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M2021 [2009-1] Nissan Engineering Standard
NES
Hot Rolled Steel Plates, Sheets and Strips for Automobiles
The materials stipulated in this NES shall meet NES M0301 "Substance Use Restrictions." 1. SCOPE (1) This Standard specifies hot-rolled steel sheets and strips (hereafter referred to as steel sheets, and when steel sheets and steel strips are indicated in distinction from each other, they shall be referred to as sheets and coils respectively) for automobiles manufactured by Nissan. (2) Steel sheets of the RP Standard shall apply to the regions where purchase is available through iron and steel manufacturers in Japan and North America approved by Nissan. Further, steel sheets of the SP standard (only for hot-rolled) in the regions where the RP Standard can apply are classified as a standard allowing continuous use only when there is a track record of placing an order. There shall be no new adoption of SP standard steel in this specific region. (Since some manufacturers may not have capability of manufacturing the steel sheets which meet RP Standard, steel types shall be determined in cooperation with the Purchase Department.) The Standard shall basically apply to new vehicles using steel types determined at Steel Decision Meetings after October 2000. 2. SPECIFICATION AND SYMBOL SYSTEM OF STEEL SHEETS The specifications of steel sheets shall be specified by the following symbol system drawing. The steel sheet specifications shall have two standard types, the RP standard (exacting specifications for thickness tolerance) and SP standard (thickness tolerance shall remain unchanged) for non-approved manufacturers. The specifications of RP standard steel sheets shall be designed per the following symbol system drawing.
RP200 (general symbol)
Classification by steel sheet type (classification by mechanical property)
221, 222, (223), 231-370, 231-440, 231-440F, 251-540, 252-540, 252-540F, 251-590, 253-590, *1) Note (Provisional) 254-590
Classification by surface finish (pickling)
P, S
Classification by lubrication
K, L
Classification by appearance (strict)
A, U
Classification by use (surface defect)
G
Classification by size
Specification according to thickness and width
Classification by standard size
The specifications of SP Standard steel sheets shall be designed per the following symbol system drawing. Classification by steel sheet type 211, 212, 221, 222, (223), 231-370, SP200 (classification by mechanical property) 231-440, 231-440F, 251-540, 252-540, (general symbol) 252-540F, 251-590, 253-590, *1) Note (Provisional) 254-590
Classification by surface finish (pickling)
P, S
Classification by lubrication
K, L
Classification by appearance (strict)
A, U
Classification by use (surface defect)
G
Classification by size
Classification by standard size
Specification according to thickness and width
Classification for thickness control
Q
plate
*1): The specifications with a "Provisional)" indication are the standards allowing continuous use only when there is a track record of placing an order using RP254-590 and SP254-590 specifications. There shall be no new adoption.
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M2021 [2009-1] 3. MECHANICAL PROPERTIES 3.1 Mechanical properties division Table 1.1 and 1.2 shall be referred to for the types and symbols of the steel sheets classified by the standard division of mechanical properties of the steel sheets. Table 1.1
Types and symbols for RP standard steel plate
Symbol Strength-class symbol
General symbol Hot-rolled mild steel sheets (General symbol: SP220)
RP220
Quasi-high tensile strength hot-rolled steel sheets (General symbol: SP230)
RP230-370 RP230-440
High strength tensile strength hot-rolled steel sheets (General symbol: SP250)
General parts for automobile use Drawing parts for automobile use Deep drawing parts for automobile use
RP231-370
370MPa class for general use
RP231-440
440MPa class for general use
RP231-440F RP251-540
RP250-540
RP252-540 RP252-540F
RP250-590 *1) Note
Table 1.2 General symbol Hot-rolled steel sheets for general use (General symbol: SP210) Hot-rolled mild steel sheets (General symbol: SP220)
Quasi-high tensile strength hot-rolled steel sheets (General symbol: SP230)
RP251-590 RP253-590 Provisional) RP254-590
440MPa class high hole expansion steel plate which facilitates burring 540MPa class for general use 540MPa class for improved formability 540MPa class high hole expansion steel plate which facilitates burring 590MPa class for general use 590MPa class low yield ratio 590MPa class for superior formability
Available thickness 1.2 to 14.0 1.2 to 8.0 1.4 to 6.0 1.4 to 14.0 1.4 to 6.0 1.6 to 12.0 1.6 to 6.0 1.6 to 5.6 1.6 to 6.0 1.4 to 3.0
Types and symbols for SP standard steel plate
Symbol Strength-class symbol
Specific symbol
Summary
SP230-370
SP231-370
Rolled steel sheet for general structure (JIS G 3101; SS330) Rolled steel sheet for general structure (JIS G 3101; SS400) General parts for automobile use Drawing parts for automobile use Deep drawing parts for automobile use 370MPa class for general use
SP230-440
SP231-440
440MPa class for general use
SP211
SP211
SP212
SP212
SP220
SP221 SP222 Provisional) SP223
SP231-440F High strength tensile strength hot-rolled steel sheets (General symbol: SP250)
Summary
Specific symbol RP221 RP222 Provisional) RP223
SP250-540
SP251-540 SP252-540 SP252-540F
SP250-590 *1) Note
RP251-590 SP253-590 Provisional) SP254-590
440MPa class high hole expansion steel plate which facilitates burring 540MPa class for general use 540MPa class for improved formability 540MPa class high hole expansion steel plate which facilitates burring 590MPa class for general use 590MPa class low yield ratio 590MPa class for superior formability
Available thickness 1.2 to 16.0 1.2 to 14.0 1.2 to 8.0 1.4 to 6.0 1.4 to 14.0 1.4 to 6.0 1.6 to 12.0 1.6 to 6.0 1.6 to 5.6 1.6 to 6.0 1.4 to 3.0
*1): The specifications with a "Provisional)" indication are the standards allowing continuous use only when there is a track record of placing an order using SP223 and RP223 specifications. There shall be no new adoption.
Reference Standards: See page 15.
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M2021 [2009-1] 3.2 Chemical composition Based on ladle analysis, the chemical composition of the steel shall meet the values shown in Table 2. Table 2
Chemical composition
C (0.15 max.) (0.10 max.)
Mn (0.60 max.) (0.50 max.)
P 0.050 max. 0.050 max. 0.050 max. 0.040 max.
Unit: % S 0.050 max. 0.050 max. 0.050 max. 0.040 max.
SP211 SP212 RP221, SP221 RP220 RP222, SP222 SP220 Provisional) (0.10 max.) (0.50 max.) 0.030 max. 0.035 max. RP223, SP223 RP231-370 0.040 max. 0.040 max. SP231-370 RP230 RP231-440 0.040 max. 0.040 max. SP230 SP231-440 RP231-440F 0.040 max. 0.020 max. SP231-440F RP251-540 0.030 max. 0.030 max. SP251-540 RP252-540 0.030 max. 0.030 max. SP252-540 RP252-540F 0.030 max. 0.020 max. RP250 SP252-540F SP250 RP251-590 Note *1) 0.10 max. 0.030 max. 0.030 max. SP251-590 RP253-590 Note *1) 0.10 max. 0.030 max. 0.030 max. SP253-590 Provisional) RP254-590 0.030 max. 0.030 max. Provisional) SP254-590 Remarks: 1. Although no specification is given for carbon and manganese, the values in parentheses ( ) are reference values for normal use. 2. When the value of SP250 or RP250 exceeds the above standard, the values shall be decided by the concerned parties. 3. Note *1) The amount of C (0.10% max.) is recommended for SP251-590, RP251-590, SP253-590, RP253-590. The chemical composition of the applicable steel types shall be reported as necessary. When the upper limit values are exceeded, the value shall be decided by the concerned parties. SP210
3.3 Tensile test The dimensional tolerance of the tensile strength, yield point and elongation of steel sheets and test pieces for use shall conform to Table 3. 3.4 Bending test When the steel sheet is bent according to Table 3, no crack or breakage shall occur on the peripheral surface.
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M2021 [2009-1] Table 3
Dimensional tolerance of the mechanical properties Unit: MPa for yield point and tensile strength, % for elongation
Test method
Tensile test
Properties
Tensile strength
Sheet thickness All in common
Grade
Yield point Less than 1.6 mm
Ref. target value
1.6 mm min. to less than 2.0 mm
Ref. target value
2.0 mm min. to less than 3.2 mm
Ref. target value
3.2 mm min. to less than 6.3 mm
Ref. target value
SP211
330 to 430
205 to
–
205 to
–
205 to
–
205 to
–
SP212
400 to 510
245 to
–
245 to
–
245 to
–
245 to
–
RP221, SP221
270 min.
205 to 325
265
195 to 315
255
185 to 305
245
175 to 295
235
RP222, SP222
270 min.
195 to 305
255
185 to 295
245
175 to 285
235
165 to 275
225
270 min.
175 to 275
225
165 to 265
215
155 to 255
205
145 to 245
195
370 min.
235 to 355
295
225 to 345
285
215 to 335
275
205 to 325
265
440 min.
295 to 410
355
285 to 400
345
275 to 390
335
265 to 380
325
440 min.
295 to 410
355
285 to 400
345
275 to 390
335
265 to 380
325
540 min.
440 to 580
510
430 to 570
500
420 to 560
490
410 to 550
480
540 min.
385 to 520
450
375 to 510
440
365 to 500
430
355 to 490
420
Provisional) RP223, SP223 RP231-370 SP231-370 RP231-440 SP231-440 RP231-440F SP231-440F RP251-540 SP251-540 RP252-540 SP252-540 RP252-540F SP252-540F RP251-590 SP251-590 RP253-590 SP253-590 Provisional) RP254-590 Provisional) SP254-590
540 min.
Not produced
375 to 510
440
365 to 500
430
355 to 490
420
590 min.
Not produced
480 to 630
555
470 to 620
545
460 to 610
535
305 to 470
390
590 min.
335 to 500
420
325 to 490
410
315 to 480
400
590 min
430 to 560
–
430 to 560
–
420 to 550
–
Table 3
Dimensional tolerance of the mechanical properties (continued)
Test method Properties Sheet thickness
Not produced
Tensile test Yield point 6.3 mm min.
Grade
Elongation
Ref. target value
Less than 1.6 mm
Target value (ref.)
1.6 mm min. to less than 2.0 mm
Target value (ref.)
2.0 mm min. to less than 2.5 mm
Target value (ref.)
2.5 mm min. to less than 3.2 mm
Target value (ref.)
SP211
205 to
–
26 to
–
26 to
–
26 to
–
SP212
245 to
–
21 to
–
21 to
–
21 to
–
RP221, SP221
165 to 285
225
35 to 49
42
36 to 50
43
37 to 51
44
37 to 51
44
RP222, SP222
155 to 265
215
37 to 51
44
38 to 52
45
39 to 53
46
39 to 53
46
135 to 235
185
40 to 53
47
41 to 54
48
42 to 55
49
42 to 55
49
195 to 315
255
33 to 46
40
34 to 47
41
35 to 48
42
35 to 48
42
255 to 370
315
28 to 41
35
29 to 42
36
30 to 43
37
32 to 45
38
Not produced
29 to 42
36
30 to 43
37
32 to 45
38
Provisional) RP223, SP223 RP231-370 SP231-370 RP231-440 SP231-440 RP231-440F SP231-440F RP251-540 SP251-540 RP252-540 SP252-540 RP252-540F SP252-540F RP251-590 SP251-590
Not produced 400 to 540
470
18 to 32
25
19 to 33
26
20 to 34
27
20 to 34
27
345 to 480
410
21 to 35
28
22 to 36
29
23 to 37
30
23 to 37
30
Not produced
Not produced
22 to 36
29
23 to 37
30
23 to 37
30
Not produced
Not produced
17 to 31
24
18 to 32
25
18 to 32
25
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M2021 [2009-1] Test method
Tensile test
Properties
Yield point
Sheet thickness
6.3 mm min.
Ref. target value
Grade RP253-590 SP253-590 Provisional) RP254-590 Provisional) SP254-590
Elongation Less than 1.6 mm
Target value (ref.)
1.6 mm min. to less than 2.0 mm
Target value (ref.)
2.0 mm min. to less than 2.5 mm
Target value (ref.)
2.5 mm min., to less than 3.2 mm
Target value (ref.)
Not produced
21 to 36
29
22 to 37
30
23 to 38
31
23 to 38
31
Not produced
28 to 44
–
29 to 45
–
29 to 45
–
29 to 45
–
Table 3
Dimensional tolerance of the mechanical properties (continued)
Test method
Test of Hole Expansion
Tensile test
Properties
Elongation
Sheet thickness 3.2 mm min. to less Grad than e 4.0 mm
Target value (ref.)
4.0 mm min. to less than 6.3 mm
Test piece
Target value (ref.)
6.3 mm min. to less than 14.0 mm
Target value (ref.)
Less than 6.3 mm
6.3 mm min.
JIS No. 1A test piece taken in the rolled direction Same as Same as the the above above JIS No. 5 test piece taken in the rolled direction Same as the above Same as – the above
JIS No. 5 test piece taken in the rolled direction
Rate of hole expansion
Test piece
–
–
–
–
–
–
–
–
–
–
SP211
26 to
–
26 to
–
SP212
21 to
–
21 to
–
RP221, SP221
38 to 52
45
38 to 52
45
39 to 53
46
RP222, SP222
40 to 54
47
41 to 55
48
41 to
48
Provisional) RP223, SP223
43 to 56
50
43 to 56
50
36 to 49
43
37 to 50
43.5
40 to
44
Same as the above
–
–
31 to 44
38
34 to 47
40.5
35 to
39
Same as the above
–
–
31 to 44
38
34 to 47
40.5
Same as the above
80 or more
Per NES M2038
RP251-540 SP251-540
21 to 35
28
21 to 35
28
JIS No. 5 test piece taken perpendicular to the rolled direction
–
–
RP252-540 SP252-540
24 to 38
31
24 to 38
31
Same as the above
–
–
RP252-540F SP252-540F
24 to 38
31
24 to 38
31
−
80 or more
Per NES M2038
RP251-590 SP251-590
19 to 33
26
Not produced
–
–
–
RP253-590 SP253-590
24 to 39
32
Not produced
–
–
–
Not produced
Not produced
RP231-370 SP231-370 RP231-440 SP231-440 RP231-440F SP231-440F
Provisional) RP254-590 Provisional) SP254-590
Not produced
Not produced 22 to 25 to
29 32
Not produced
-5-
Same as the above Same as the above Same as the above Same as the above
–
–
M2021 [2009-1] Table 3
Dimensional tolerance of the mechanical properties (continued)
Test method Properties Grade
Bending test Bending angle
Inner radius Less than 3.2 mm
3.2 mm min.
Test piece
SP211
180°
0.5 x thickness
JIS No. 1 test piece taken in the rolled direction
SP212
180°
1.5 x thickness
Same as the above
RP221, SP221
180°
RP222, SP222 Provisional) RP223, SP223 RP231-370 SP231-370 RP231-440 SP231-440 RP231-440F SP231-440F RP251-540 SP251-540 RP252-540 SP252-540 RP252-540F SP252-540F RP251-590 SP251-590 RP253-590 SP253-590 Provisional) RP254-590 Provisional) SP254-590
180°
Close contact
JIS No. 3 test piece taken in the rolled direction Same as the above
180°
Close contact
Same as the above
180°
1.0 x thickness
JIS No. 3 test piece taken perpendicular to the rolled direction
180°
1.0 x thickness
Same as the above
180°
1.0 x thickness
Same as the above
Close contact
0.5 x thickness
180°
1.0 x thickness
1.5 x thickness
Same as the above
180°
1.0 x thickness
1.5 x thickness
Same as the above
180°
1.0 x thickness
1.5 x thickness
Same as the above
180°
1.5 x thickness
Same as the above
180°
1.5 x thickness
Same as the above
180°
1.5 x thickness
Same as the above
3.5 High-speed strength of deformation (Applicable at the time of process approval test) This Standard is applicable to RP251-590, RP253-590, (provisional) RP254-590, SP251-590, SP253-590 and (provisional) SP254-590 only. Tensile strength at strain rate 1,000/sec: 730 MPa min. Evaluating method shall be established in a separate NES section.
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M2021 [2009-1] 4. SURFACE AND INTERNAL DEFECTS 4.1Classification by appearance (strict) The surface of the steel sheets shall be free from harmful flaws or scabs, etc. (hereafter referred to as defects) affecting their use. However, minor defects are allowed to exist on the surface of the coils depending on their characteristics. The nature and quantity of these defects are subject to agreement between the concerned parties. The allowable conditions for appearance(strict) is specified in Table 4. This specification in principle shall be applied to one side of the sheet. Table 4
Classification by appearance
Classification by appearance Strict
Symbol A AU
Normal
Remark:
–
Surface to be applied Steel sheet Strip Upper surface Lower surface Upper surface
Outer surface Inner surface Outer surface
Application Applied to steels for strict surface quality after painting or plating and steels that do not allow fine waviness on the surface for function. Applied to usage for non-“strict” quality on the steel sheet.
If the surface is not specified for division of appearance, no defect on the surface shall be allowed during stamping.
4.2 Internal defect The steel sheets shall not contain harmful defects affecting their use, e.g. two-ply and lamination. The concerned parties shall specify the method of inspection and the required freedom from internal defects, which even in minute form could adversely affect the performance of the finished part, particularly in vital parts. 5. SURFACE FINISH DIVISION The surface finish division of steel sheets is specified in Table 6. Table 6 Surface finish Surface finish division symbol Summary Mill oxide finish – As hot rolled. Pickled finish P Remove scale (iron oxide) by pickling. Apply to the sheet in thickness (over 6 mm) unavailable for Shot blast roll finish S pickling process and required for removing scale. 6. LUBRICANT DIVISION Unless otherwise specified, the steel sheets shall be lubricated. (However, no lubricant shall be used for mill oxide finish sheets..) Classification, symbol and summary of solid lubricants shall conform to Table 7. Lubricant division Normal lubricant High-lubrication anti-rust oil Special anti-rust oil Solid lubricant
Table 7 Symbol – L K
Application of solid lubricant Summary – Anti-rust oil also used as press oil Used to improve sliding performance while pressing, or stop using press oil.
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M2021 [2009-1] 7. STANDARD SIZE AND DIMENSIONAL TOLERANCE 7.1 Standard thickness The standard thickness shall conform to Table 8.1 and 8.2. Table 8.1 Standard thickness
Remark:
(1.2) 3.1 13.0
(1.3) 3.2
Remark:
2.0 5.0
2.2 5.6
2.3 6.0
2.5 6.3
2.6 7.0
2.8 8.0
2.9 9.0
3.0 10.0
12.0
The thickness shown in parentheses ( ) shall be considered the possibility of production and cost difference with the cold-rolled steel sheets. (NES M 2020, 2032) Table 8.2
Standard thickness
Standard thickness for RP standard steel plate
(1.4) (1.5) 1.6 1.7 1.8 1.9 3.5 3.6 3.9 4.0 4.4 4.5
(1.2) 4.0
(1.4) 4.5
1.6 5.0
Standard thickness for SP standard steel plate 1.8 5.6
2.0 6.0
2.3 6.3
2.5 7.0
2.6 8.0
2.8 9.0
2.9 10.0
3.2 11.0
3.6 12.0
3.8 13.0
14.0
The thickness shown in parentheses ( ) shall be considered the possibility of production and cost difference with the cold-rolled steel sheets. (NES M 2020, 2032)
7.2 Dimensional tolerance in thickness The dimensional tolerance in thickness shall conform to Table 9.1, 2, 3, 4. Table 9.1
Thickness dimensional tolerance for RP standard steel plate (in cases where cold rolled base sheets are used) Unit: mm
Classification by strength type Classification by nominal
RP221, RP222 RP223
thickness
RP231-370
RP251-540, RP252-540
RP231-440
RP252-540F, RP251-590, RP253-590R,
RP231-440F
(Provisional) RP254-590
1.20 min. to less than 1.60
±0.10
±0.10
±0.13
1.60 min. to less than 2.10
±0.10
±0.11
±0.13
2.10 min. to less than 2.60
±0.10
±0.11
±0.13
2.60 min. to less than 2.90
±0.11
±0.11
±0.14
2.90 min. to less than 3.10
±0.11
±0.13
±0.14
3.10 min. to less than 3.60
±0.11
±0.13
±0.15
3.60 min. to less than 4.10
±0.12
±0.14
±0.16
4.10 min. to less than 5.10
±0.14
±0.16
±0.17
5.10 min. to less than 6.10
±0.15
±0.17
±0.18
6.10 min. to less than 7.10
±0.16
±0.18
-
7.10 min. to less than 8.10
±0.17
±0.19
-
8.10 min. to less than 9.10
±0.18
±0.20
-
9.10 min. to less than 14.1
±0.19
±0.26
-
Remarks: 1. The thickness shall be measured at any point more than 40 mm inward from the side edge. 2. The nominal thickness means the thickness of the base sheet. 3. This specification shall not apply to abnormal parts of coil. 4. A special restrictive dimensional tolerance may be specified by agreement between the parties concerned, if specifically necessary. 5. The thickness dimensional tolerance of the RP standard steel sheet shall not be changed depending on the sheet width.
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M2021 [2009-1] Table 9.2 mm
Dimensional tolerance in thickness for SP standard general rolled steel sheet (Dimensional tolerance in thickness specified in JIS G 3193)
Classification by nominal width Classification by nominal thickness
Less than 1.25 1.25 min. to less than 1.60 1.60 min. to less than 2.00 2.00 min. to less than 2.50 2.50 min. to less than 3.15 3.15 min. to less than 4.00 4.00 min. to less than 5.00 5.00 min. to less than 6.30 6.30 min. to less than 10.0 10.0 min. to less than 16.0 Remarks:
Unit:
Less than 1,600
1,600 min. to less than 2,000
2,000 min. to less than 2,500
2,500 min. to less than 3,150
3,150 min. to less than 4,000
4,000 min. to less than 5,000
±0.16 ±0.18 ±0.19 ±0.20 ±0.22 ±0.24 ±0.45 ±0.50 ±0.55 ±0.55
– – ±0.23 ±0.25 ±0.29 ±0.34 ±0.55 ±0.60 ±0.65 ±0.65
– – – – ±0.29 ±0.34 ±0.55 ±0.60 ±0.65 ±0.65
– – – – – – ±0.65 ±0.75 ±0.80 ±0.80
– – – – – – – ±0.75 ±0.80 ±0.80
– – – – – – – – ±0.90 ±1.00
1. Either plus side or minus side of the tolerance given in the above table may be restricted on demand. In this case, however, the total range of dimensional tolerance shall be equal to the total range of tolerance in the above table. 2. The thickness of the steel coils shall be measured at any point of 25 mm minimum inward from the edge of mill-edged coils and plates cut from the coils of 50 mm minimum in width, and at the middle of those of less than 50 mm in width and at any point of 15 mm minimum inward from the edge of trim-edged coils and plates cut from the coils of 30 mm minimum in width, and at the center of those of less than 30 mm in width. The thickness of the steel sheets left as rolled shall be measured at any point inward from a line on which they are to be cut widthwise, and that of trim-edged sheets shall be measured at any point 15 mm minimum inward from the edge thereof. 3. Dimensional tolerance of thickness for steel types with “Q” shall be controlled so that the lower dimensional tolerance is more strict (dimensional tolerance shown above Table 9.1 - nominal thickness x 0.02), and upper dimensional tolerance (dimensional tolerance shown above Table 9.1 + nominal thickness x 0.02) is within the upper limits. Total dimensional tolerance range is unchanged.
Table 9.3 Dimensional tolerance in thickness for SP standard hot-rolled mild steel sheets (Dimensional tolerance in thickness specified in JIS G 3131)
Unit: mm Classification by nominal width Classification by nominal thickness
Less than 1.60 1.60 min. to less than 2.00 2.00 min. to less than 2.50 2.50 min. to less than 3.15 3.15 min. to less than 4.00 4.00 min. to less than 5.00 5.00 min. to less than 6.00 6.00 min. to less than 8.00 8.00 min. to less than 10.0 10.0 min. to less than 12.5 12.5 min. to 14.0 max. Remarks:
Less than 1,200
1,200 min. to less than 1,500
1,500 min. to less than 1,800
1,800 min. to less than 2,300
±0.14 ±0.16 ±0.17 ±0.19 ±0.21 ±0.24 ±0.26 ±0.29 ±0.32 ±0.35 ±0.38
±0.15 ±0.17 ±0.19 ±0.21 ±0.23 ±0.26 ±0.28 ±0.30 ±0.33 ±0.36 ±0.39
±0.16 ±0.18 ±0.21 ±0.24 ±0.26 ±0.28 ±0.29 ±0.31 ±0.34 ±0.37 ±0.40
– ±0.21 ±0.25 ±0.26 ±0.27 ±0.29 ±0.31 ±0.35 ±0.40 ±0.45 ±0.50
1. The thickness of the steel plates shall be measured at any point 20 mm minimum inward from the edge thereof. However, that of the steel plates less than 40 mm in width shall be measured at the middle thereof. 2. This table shall not be applied to on abnormal parts of coils. 3. Dimensional tolerance of thickness for steel types with “Q” shall be controlled so that the lower dimensional tolerance is more strict (dimensional tolerance shown above Table 9.3 - nominal thickness x 0.02), and upper dimensional tolerance (dimensional tolerance shown above Table 9.3 + nominal thickness x 0.02) is within the upper limits. Total dimensional tolerance range is unchanged.
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M2021 [2009-1] Table 9.4
Dimensional tolerance in thickness for SP standard quasi-high tensile strength hot-rolled steel sheet (Dimensional tolerance in thickness specified in JIS G 3113)
Unit: mm Classification by nominal width Classification by nominal thickness
1.60 min. to less than 2.00 2.00 min. to less than 2.50 2.50 min. to less than 3.15 3.15 min. to less than 4.00 4.00 min. to less than 5.00 5.00 min. to less than 6.00 6.00 min. to less than 8.00 8.00 min. to less than 10.0 10.0 min. to less than 12.5 12.5 min. to 14.0 max. Remarks:
Table 9-5
1,200 min. to less than 1,500
1,500 min. to less than 1,800
1,800 min. to less than 2,300
±0.16 ±0.17 ±0.19 ±0.21 ±0.24 ±0.26 ±0.29 ±0.32 ±0.35 ±0.38
±0.17 ±0.19 ±0.21 ±0.23 ±0.26 ±0.28 ±0.30 ±0.33 ±0.36 ±0.39
±0.18 ±0.21 ±0.24 ±0.26 ±0.28 ±0.29 ±0.31 ±0.34 ±0.37 ±0.40
– – – – ±0.29 ±0.31 ±0.35 ±0.40 ±0.45 ±0.50
1. For the steel plate of less than 1.6 mm thickness, dimensional tolerance in thickness specified in JIS G 3131 shall be applied. (refer to Table 9.3) 2. Remark 1 of Table 9.2 shall be referred to for the place of measurement of the thickness. 3. This table shall not be applied to on abnormal parts of coils. 4. Dimensional tolerance of thickness for steel types with “Q” shall be controlled so that the lower dimensional tolerance is more strict (dimensional tolerance shown above Table 9.4 - nominal thickness x 0.02), and upper dimensional tolerance (dimensional tolerance shown above Table 9.4 + nominal thickness x 0.02) is within the upper limits. Total dimensional tolerance range is unchanged.
Dimensional tolerance in thickness for SP standard high tensile strength hot-rolled steel sheets (Dimensional Tolerance in thickness specified in JIS G 3134) Unit: mm
Classification by nominal width Classification by nominal thickness
1.60 min. to less than 2.00 2.00 min. to less than 2.50 2.50 min. to less than 3.15 3.15 min. to less than 4.00 4.00 min. to less than 5.00 5.00 min. to less than 6.00 6.00 Remarks:
Less than 1,200
Less than 1,200
1,200 min. to less than 1,500
1,500 min. to less than 1,800
1,800 min. to less than 2,180
±0.16 ±0.18 ±0.20 ±0.23 ±0.26 ±0.29 ±0.32
±0.19 ±0.22 ±0.24 ±0.26 ±0.29 ±0.31 ±0.33
±0.20 ±0.23 ±0.26 ±0.28 ±0.31 ±0.32 ±0.34
– ±0.25 ±0.29 ±0.30 ±0.32 ±0.34 ±0.38
1. For the steel plate of less than 1.6 mm thickness, dimensional tolerance in thickness specified in JIS G 3131 shall be applied (refer to Table 9.3). 2. Remark 1 of Table 9.2 shall be referred to for the place of measurement of the thickness. 3. This table shall not be applied to on abnormal parts of coils. 4. Dimensional tolerance of thickness for steel types with “Q” shall be controlled so that the lower dimensional tolerance is more strict (dimensional tolerance shown above Table 9.5 - nominal thickness x 0.02), and upper dimensional tolerance (dimensional tolerance shown above Table 9.5 + nominal thickness x 0.02) is within the upper limits. Total dimensional tolerance range is unchanged.
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M2021 [2009-1] 7.3 Standard width The standard width shall conform to Table 10. Table 10
Standard width Unit: mm
914 600 1,180 2,100
1,219 630 1,200 2,500
1,524 670 1,250 2,600
1,829 710 1,300 2,800
2,134 750 1,320 3,000
2,438 800 1,400
3,048 850 1,500
900 1,600
950 1,700
1,000 1,800
1,060 1,900
1,100 2,000
1,120
7.4 Dimensional tolerance in width The dimensional tolerance in width shall conform to Table 11. Table 11
Dimensional Tolerance for width Unit: mm
Dimensional tolerance A B Classification by Classification by nominal C Trim-edged ordinary Re-sheared steel nominal width thickness Slitted steel plates plates steel plates + + ±0.3 0 2.0 0 5 Less than 3.15 Less than 160 ±0.5 0 3.0 0 5 3.15 min. to less than 6.00 – 0 4.0 0 10 6.00 min. to less than 20.0 Less than 3.15 5 0 2.0 0 ±0.4 160 min. to less 3.15 min. to less than 6.00 5 0 3.0 0 ±0.5 than 250 6.00 min. to less than 20.0 10 0 4.0 0 – Less than 3.15 5 0 2.0 0 ±0.5 250 min. to less 3.15 min. to less than 6.00 5 0 3.0 0 ±0.5 than 400 6.00 min. to less than 20.0 10 0 4.0 0 – Less than 3.15 10 0 3.0 0 ±0.5 400 min. to less 3.15 min. to less than 6.00 10 0 3.0 0 ±0.5 than 630 6.00 min. to less than 20.0 10 0 5.0 0 – – 0 4.0 0 10 Less than 3.15 630 min. to less – 0 4.0 0 10 3.15 min. to less than 6.00 than 1,000 – 0 6.0 0 10 6.00 min. to less than 20.0 Less than 3.15 10 0 4.0 0 – 1,000 min. to 3.15 min. to less than 6.00 10 0 4.0 0 – less than 1,250 6.00 min. to less than 20.0 10 0 6.0 0 – Less than 3.15 10 0 4.0 0 – 1,250 min. to 3.15 min. to less than 6.00 10 0 4.0 0 – less than 1,600 6.00 min. to less than 20.0 10 0 6.0 0 – – 0 4.0 0 10 Less than 3.15 – 0 4.0 0 10 1,600 min. 3.15 min. to less than 6.00 – 0 6.0 0 10 6.00 min. to less than 20.0 Remarks: 1. Dimensional tolerance A shall be applied unless otherwise specified. 2. Dimensional tolerance in width of mill-edged steel plates shall be determined by agreement between the parties concerned.
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M2021 [2009-1] 7.5 Dimensional tolerance in length of sheet The dimensional tolerance in the length of the sheet shall conform to Table 12. Table 12
Dimensional tolerance in Length of Sheet (Dimensional tolerance in length of JIS G 3193) Unit: mm Dimensional tolerance Classification by Classification by A B nominal length nominal thickness Cut by ordinary method Re-sheared or cut accurately +25 +5 Less than 6.0 0 0 Less than 6,300 +25 +10 6.0 min. 0 0 +0.5% +10 Less than 6.0 0 0 6,300 min. +0.5% +15 6.0 min. 0 0 8. SHAPE 8.1 Flatness The maximum value of flatness for steel sheets shall conform to Table 13. Table 13
Flatness (Flatness specified in JIS G 3193) Unit: mm
Classification by nominal thickness
Less than 1,250
1,250 min. to less than 1,600
1,600 min. to less than 2,000
2,000 min. to less than 3,000
3,000 min.
Classification by nominal width Less than 1.60 18 20 – – – 1.60 min. to less than 3.15 16 18 20 – – 3.15 min. to less than 4.00 16 16 16 – – 4.00 min. to less than 6.00 14 14 14 24 25 6.00 min. to less than 10.0 13 13 13 21 22 10.0 min. to less than 25.0 12 12 12 16 17 Remarks: 1. The value of the flatness means a value obtained by deducting the nominal thickness of steel sheet placed on the surface plate from the measured value of maximum strain. (Figure 1) 2. This table shall not be applied to mill-edged steel plates. 3. This table shall not be applied to steel plates supplied after they are straightened by a stretcher leveller. 4. The above table shall be applied to a length of 2,000 mm selected arbitrarily and to the total length of a steel plate that measures less than 2,000 in length. Figure 1 Thickness (t)
Maximum strain (h)
Flatness = (h−t)
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M2021 [2009-1] 8.2 Lateral curvature The maximum values of lateral curvature are specified in Table 14.1, 2 and the measuring method thereof shall conform to Figure 2. Table 14.1
Lateral curvature of sheets (Lateral curvature specified in JIS G 3193) Unit: mm
Classification by nominal width Classification by nominal length
250 min. to less than 630
630 min. to less than 1,000
1,000 min.
Less than 2,500 5 4 3 2,500 min. to less than 8 6 5 4,000 4,000 min. to less than 12 10 8 6,300 6,300 min. to less than 20 16 12 10,000 10,000 min. 20 per 10,000 (arbitrary) 16 per 10,000 (arbitrary) 12 per 10,000 (arbitrary) Remarks: 1. Table 14.2 shall be applied to lateral curvature of steel plates less than 250 mm in width. 2. This table shall not be applied to mill-edged steel plates. Table 14.2
Lateral curvature of coils (Lateral curvature specified in JIS G 3193) Unit: mm
Remark:
Classification by nominal width Less than 250 250 min. This table shall not be applied to mill-edged steel plates.
Maximum value 8 per 2,000 (arbitrary) 5 per 2,000 (arbitrary)
Figure 2 Lateral curvature
Lateral curvature
Width
Width
10,000 mm (Sheet less than 10,000 mm in length)
Lateral curvature
(Sheet 10,000 mm min. in length)
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Width
2,000 mm
Coil
M2021 [2009-1] 8.3 Deviation from a right angle in the sheets Deviation from a right angle in the sheets shall be denoted by A/W in Figure 3 and must not exceed 1.0%. Figure 3 (Deviation from a right angle specified in JIS G 3193)
Remarks: 1. A is a measured value and W is a nominal width. 2. This figure shall not be applied to mill-edged steel plates.
9. TEST Testing methods and test pieces shall conform to Table 15.
Test name Tensile test Bending test
Table 15 Testing method JIS Z 2241 (Method of tensile test for metal materials) JIS Z 2248 (Method of bend test for metal materials)
Testing method and test pieces Test piece No. 5 test piece specified in JIS Z 2201 (Test pieces for tensile test for metallic materials) No. 1 and No. 3 test pieces specified in JIS Z 2204 (Bend test pieces of metal materials)
Remarks When otherwise specified, No. 1A test piece specified in JIS Z 2201.
10. INSPECTION Inspection results of chemical composition, mechanical properties, internal defects, surface defects, surface finish, tolerance in shape and dimension shall pass the specifications in sections 3, 4, 5, 6, 7, and 8. 11. NOTATION Steel sheets which have passed inspections shall have, in a suitable method, notation of symbol, inspection No. or manufacturing No., size, number of sheets or weight, and manufacturer's name or its abbreviation.
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M2021 [2009-1] 12. NOTATION OF SYMBOLS Symbols of the steel sheet shall be, as a rule, indicated in the order of grade, use division, surface finish division, lubricant division, appearance classification, use classification, thickness, width and length. For example, the order of each symbol shall be as designated below. SP221 (or other grade name) P (S) KAGQ (Q is not applicable to RP standard steel plate.) Further, in the case of the coil, length shall be indicated as C (feed length) or COIL. (feed length) Example for symbol: SP211 1.6 x 600 x 700 Ordinary rolled steel sheet (equivalent to SS330) with mill oxide finish, thickness of 1.6, width of 600, and feed length of 700 SP222P 2.3 x 700 x C Automobile drawing sheet; with pickling finish, coil in thickness of 2.3 and width of 700 SP252-540FPK Steel sheets with 540 MPa class high hole expansion, pickling finish and applied with solid lubricant 13. DRAWING NOTATION When the steel sheets are identified on drawings, the grade symbols of steel, surface finish and thickness shall be indicated. However, if it is necessary to designate the mechanical properties of steel sheet, specification symbols can be indicated. Example SP220P t2.3 SP230-370P t1.6 SP253-590P t2.0 (designation of low yield ratio type high tensile strength steel sheets) 14. REPORT When a manufacturing process and an item decided between the parties concerned are changed, the manufacturer shall report to that effect and obtain approval. Further, a report shall be submitted to the Material Department, Production Engineering Department, and Material Development Department of Nissan Motor Company, if a change affects overall Nissan organization, or to the Engineering and Inspection Departments of the plant concerned if a change affects a specific plant. 15. OTHERS (1) The steel plates to which special treatment is applied such as steel plates covered with vinyl shall be indicated by adding a new symbol to the end of the existing symbols after consulting with the Material Administration Department. As for the technical detail, they shall be decided by agreement between the parties concerned. (2) The type of packing, weight, the inner and outer diameters of coils shall be decided by each plant according to the agreement between the parties concerned. 16. REFERENCE STANDARD JFS A 1001 - 1998 Hot Rolled Steel Plates, Sheets and Strips for Automobiles JFS A 1001 - 2008 Hot Rolled Steel Plates, Sheets and Strips for Automobiles JIS G 3101 - 1987 Rolled steels for general structure JIS G 3131 - 1996 Hot rolled mind steel plates, sheets and strip JIS G 3113 - 1996 Hot rolled steel plates, sheets and strip for automobile structural uses JIS G 3134 - 1990 Hot rolled high strength steel sheets with improved formability for automobile structural uses JIS G 3193 - 1990 Dimensions, mass and permissible variations of hot rolled steel plates, sheets and strip JIS Z 2241 - 1998 Method of tensile test for metallic materials JIS Z 2201 - 1998 Test pieces for tensile test for metallic materials JIS Z 2248 - 1996 Method of bend test for metallic materials JIS Z 2204 - 1996 Bend test pieces for metallic materials NES M 0301 - 2008-N Substance Use Restrictions NES M 2020 - 2006-N Cold Rolled Carbon Steel Sheets and Strips for Automobiles NES M 2032 - 2006-N High Tensile Strength Cold Rolled Carbon Steel Sheets and Strips for Automobiles NES M 2038 - 2001-N Test Method of Hole Expansion
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M2021 [2009-1] (Reference) New/Conventional Standard Comparison Chart Before revision in 1995 After revision in 2000 After revision in 2008 NP210 SP210 SP210 NP211 SP211 SP211 NP212 SP212 SP212 NP220 SP220, RP220 SP220, RP220 SP221, RP221 NP221 SP221, RP221 SP222, RP222 NP222 SP222, RP222 SP223, RP223 NP223 SP223, RP223 NP230 SP230, RP230 SP230, RP230 NP231
(Provisional)
NP232 NP233
SP230-310 SP231-370 RP231-370
(Provisional)
SP230-400
Eliminated
Remarks General rolled steel sheet Equivalent to JIS SS330 Equivalent to JIS SS400 Mild steel sheet (270MPa class)
Quasi-high tensile strength steel sheet 310MPa class high tensile strength steel sheet
SP231-370 370MPa class high tensile RP231-370 strength steel sheet Eliminated 400MPa class high tensile strength steel sheet
NP234 NP240
SP231-440(F) SP231-440(F) 440MPa class high tensile RP231-440(F) RP231-440(F) strength steel sheet SP250, RP250 SP250, RP250 High tensile strength steel sheet NP241 (Provisional) SP250-490 Eliminated 490MPa class high tensile strength steel sheet NP242(F)
SP251-540 RP251-540 SP252-540(F) RP252-540(F) -
No setting No setting
SP253-590 RP253-590 SP254-590 RP254-590
No setting No setting
(Provisional)
SP250-690
SP251-540 RP251-540 SP252-540(F) RP252-540(F) SP251-590 RP251-590 SP253-590 RP253-590 (Provisional) SP254-590 (Provisional) RP254-590 Eliminated
540MPa class high tensile strength steel sheet 590MPa class high tensile strength steel sheet
690MPa class high tensile strength steel sheet
Provisional standards are enclosed within a frame and are to be used for orders placed using the conventional standards. New standards are inapplicable in this case. *Steel sheets of the same grade are not classified by mechanical properties. This is true of both the old and new standards. Append an “0” as the final digit to indicate steel type.
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M2021 [2009-1] ANNEX Major points in the Jun 2009 revision Through production improvement and rationalization of steel manufacturer, etc. due to the steel type reduction, such as small volume steel type and steel type that is difficult to manufacture, the revision for abolishment of below steel type shall be performed for the purpose of steel plate stable purchasing (volume, cost and quality). Revision content at this time including other steel type of steel plate related NES, shall be as shown below. Standard No. M2021
M2027
Standard Name Hot Rolled Steel Plates, Sheets and Strip for Automobiles Zinc Coating (Hot-Dipped) on Steel Plates and Steel Strips for Automobiles
Steel type SP223 SP782-440 SP793
Revision content Temporal standardization Temporal standardization Temporal standardization
Remark New adoption shall not be allowed. New adoption shall not be allowed. New adoption shall not be allowed.
Major points in the March 2009 revision (1) Review in response to the revision of JFS standard The chemical compositions and mechanical properties (YP, TS, EL) have been changed in accordance with JFS standards (excluding TS: 590 MPa grade) in response to the revision of Japan Iron and Steel Federation standard "Hot rolled steel sheets and strip for automobile use" (JFS A1001) in April 2008. Because the mechanical property range for a steel type of 590 MPa or more is wide, and is considered to affect applicable parts and part performance, handling method will be studied continuously with the blast furnace steel manufacturer. The available thickness has also been changed in accordance with the JFS standard. (2) Raising of the lower limit of applicable thickness of hot rolled steel sheets (exceeding 1.4 mm ⇒ 1.6 mm or more) The lower limit of applicable thickness of hot rolled steel sheets has been raised after taking into consideration the comment from the blast furnace steel manufacturer that productivity of thin hot rolled steel sheets is poor at a hot rolling plant, which inhibits throughput improvement of the overall holt rolled products. Major points in the March 2008 revision Although there were standards for low yield ratio steel sheets (RP253-590, SP253-590) as the 590 MPa class of high tensile strength steel in the conventional standards, there were no standards for high yield ratio steel sheets. Therefore, high yield ratio steel sheets (RP251-590, SP251-590) were newly standardized for the purpose of cost reduction. In addition, the specifications for the standard values of the material characteristics of the newly established steel types were matched to the Japan Iron and Steel Federation standard (JFS revised in fiscal 2008). However, specifications for the upper limit value of the amount of C were added from the viewpoint of spot welding quality, and specifications for the high-speed strength of deformation were added from the viewpoint of high-speed collision. Japan Iron and Steel Federation standard High hole expansion type A JSH590A High hole expansion type A JSH590B High yield ratio type JSH590R Low yield ratio type JSH590Y -
NES standard SP251-590 SP253-590 SP254-590
Points of partial revision in March 2006 Description of "The materials stipulated in this NES shall meet NES M0301 "Substance Use Restrictions."" was added at the beginning of the text. Normative Reference NES M0301-2005-1 Major points in the February 2002 revision The RP standard steel sheets are available to be purchased through iron and steel manufacturers in Japan (refer to revision in October 2000) and North America (LTV, Bethlehem, USS) approved by Nissan. Major points in the October 2000 revision Steel sheets of the RP standard were newly established for the main purpose of the 3 items mentioned below. (1) Review of setting of plate thickness (gauge and tolerance) to design optimized parts (2) Standard integration with Renault (3) Further reduction of material cost Main changing points are as follows.
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M2021 [2009-1] 1)
2)
3) 4)
5)
6)
For the purpose of 1 gauge down ( 0.1 mm) of plate thickness whose actual purchasing amount in fiscal 1999 was large, the standard dimensions of thickness for hot rolled steel sheets of the RP standard, 1.3, 1.5, 1.7, 1.9, 2.2, 3.0, 3.1, 3.5, 3.9, 4.0, and 4.4 (unit: mm) were newly established. However, for plate thickness of 5.0 mm or more, new ones are not especially established because the same or better gauge-down effect can be obtained by the SP standard steel plate with Q. Plate thickness of 11.0, 12.7, and 14.0 without actual results of purchasing in fiscal 1999 was deleted. For dimensional tolerance of thickness of the RP standard steel sheets, classification according to the strength-class symbols was set to integrate with the Renault standard and classification by nominal width was abolished. In addition, thickness dimensional tolerance was narrowed to the range similar to the Renault standard compared with the SP standard steel sheet. Application of classification Q by dimension control of the SP standard is not acceptable for the RP standard steel sheets because of the narrowing of the range of thickness dimensional tolerance. Although it is possible to purchase the RP standard steel sheets through Japanese iron and steel manufacturers (Nippon Steel Corporation, Kawasaki Steel, NKK, Kobe Steel) approved by Nissan, other manufacturers are not acceptable at this moment. In the case of purchasing through the procurement section of Renault, the Renault standard is applied. However, it is necessary to pay attention that the plate thickness type and tolerance of hot rolled mild steel sheets of the RP standard are the same as the Renault standard, and the dimensional tolerance is different between quasi-high-strength hot rolled steel sheets and high-strength hot rolled steel sheets according to strength types. (The RP standard steel sheets may not be able to be delivered or may be specially controlled materials in regions other than Japan and the regions handled by the Renault procurement section because of the narrowing of the range of plate thickness dimensional tolerance.) Although the RP standard steel sheets are basically applied from new vehicles in and after October 2000, it is possible to replace the SP standard steel sheets by the RP standard steel sheets based on agreement between the parties concerned in some cases. (It is not acceptable to replace the RP standard steel sheets by the SP standard steel sheets.) Measuring places for thickness of the RP standard steel sheets matched the Renault standard and were changed to arbitrary points of the inner side 40 mm or more away from the side edges.
Major points in the June 2000 revision Use of quasi-high tensile strength steel sheets of the 440 MPa class and high tensile strength steel sheets of the 540 MPa and 590 MPa classes were diversified as a measure of weight reduction. High hole expansion steel sheets (440 MPa and 540 MPa) that were planned to be standardized after establishment of the test method were standardized. In addition, the high tensile strength steel sheets of the 690 MPa class that was not intended to be expanded for adoption but was partially used were tentatively standardized. Supplementary explanation regarding revised items Addition of new steel types (SP231-440F, SP252-540F) Steel sheets whose hole expansion property was excellent among SP231-440 and SP252-540 of the conventional standard were newly established by affixing F. Although there were types of A and B as high hole expansion steel sheets in the standard of the Japan Iron and Steel Federation (hereinafter referred as the JFS standard) and a total 7 types were set, the minimum necessary steel types were set from the viewpoint of reduction of steel types. Relevant standards are as follows. For the classes of 540 MPa and 440 MPa, one type was respectively set because in the type A of the JFS standard of the 540 MPa class, the difference between it and the usual improved formability material (SP252-540) was not clear and in the type B of the JFS standard of the 440 MPa class, it was judged that the type A was able to substitute for the type B in formability. In addition, compared with SP231-440 and SP252-540, mechanical characteristic values are the same except the rate of hole expansion, and types with F are decided to be positioned as derivative steel types.
JFS standard (JSF A1001) Rate of hole Symbol of type expansion JSH370A 90 min. High hole JSH440A 80 min. expansion steel JSH540A 60 min. sheet A JSH590A 55 min. JSH440B 100 min. High hole expansion steel JSH540B 80 min. sheet B JSH590B 60 min.
NES standard (NES 2021) Rate of hole Steel type expansion ― No setting SP321-440F 80 min. ― No setting ― No setting ― No setting SP252-540F 80 min. ― No setting
Remark: The rate of hole expansion is the indicator of formability measured in the JFS standard (JFS T1001) and NES 2038 Test Method of Hole Expansion. The bigger the values are, the better formability is.
Major points in the May 2000 revision Inner surfaces (lower surface) designation classification of the appearance application surfaces are described by newly setting the symbol (“U”) for the strict appearance materials (“A”).
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M2021 [2009-1] Major points in the 1999 revision (1) Addition of new steel type (SP254-590) (2) Addition of available thickness (SP230: 1.2t, SP250: 1.4t) (3) Review and change in the range of thickness classification of mechanical properties (4) New establishment of appearance classification (A: strict appearance material) (5) New establishment of usage classification (G: surface defect control use) (6) Addition of lubricant classification (L: high lubrication antirust oil) (7) Addition of classification for dimension control (Q) to classification by size (8) New establishment of high-speed strength of deformation (9) Deletion of conventional units (application of phase 3 of SI unit) Supplementary explanation regarding revised items (1) New addition of steel type (new high tensile strength steel of 590 MPa class) Although there was low yield ratio steel sheets (SP253-590) as the 590 MPa class of high tensile strength steel in the conventional standards, high residual austenite type TRIP steel high tensile strength steel that had the characteristic of high elongation was newly established as superior formability steel sheets (SP254-590). Note that it was described regarding steel type symbols in ANNEX at the revision in 1996 that SP**4 was planned to be high hole expansion steel sheets (high burring workability steel sheets), but it was decided to be SP254-590 for consistency with the steel type symbol (superior workability = SP154-590) in the cold rolled high tensile strength steel standard (M2023). (2) Addition of available thickness Although a change from cold rolled materials to hot rolled materials for the purpose of cost reduction and weight reduction by reduction of plate thickness are adopted in quasi-high tensile strength steel materials or high tensile strength steel materials, there are some problems in the lower limit of plate thickness. The lower limit was newly established within the range of the actual ability of steel manufacturers. Concretely speaking, 1.2t of SP231, 1.4t of SP251 and SP252, and 1.4t and 1.6t of SP253 were newly established. 3) Change and addition of mechanical properties 1. Change in sheet thickness classification 1.2 mm, 1.6 mm, 2.0 mm, 3.2 mm, 6.3 mm were adopted for the purpose of consistency with the JFS standard in plate thickness classification of yield points and total elongation. The upper limit of the standard was decided to be 6.3 mm min. (less than 6.3 mm is not established) and the range in which purchasing is possible was decided to be the upper limit. 2. Name change of target value Although the median value of the allowable range of mechanical characteristics of each steel type was conventionally decided to be the “target value” as a guideline of selection of steel types (grade), it was changed to “Reference target value” for consistency with the JFS standard (for low carbon steel sheets, yield point: reference value, elongation: target value, and for quasi-high tensile strength steel sheets and high tensile strength steel sheets, yield point: target value, elongation: reference value). 3. Addition of superior formability steel sheets Superior formability steel sheets (SP254-590) were newly established in consideration of actual manufacturing ability. However, for characteristic values other than the tensile test, the conventional standard was carried over. Revision of (4) appearance classification and (5) usage classification Standardization of strict appearance was divided into “Appearance classification” that was related to existence of assurance of scratches and “Usage classification” that was related to the mixing rate in the case of existence of scratch assurance and established. Revision contents are as follows. System Appearance classification
Name and symbol Strict (A) Normal (No symbol) (Cold rolled base sheet: (B))
Usage classification (Applied to A)
For surface defect control (G) For general (no symbol)
Concept This is the classification according to the presence of assurance of material surface quality (scratches, etc.). Strict appearance covers even fine surface defects but normal appearance does not cover them. However, surface defects that cause cracks in processing were outside of the standard regardless of this classification. This is the classification according to the degree of surface defects based on appearance classification.
For the appearance classification, materials whose surface quality was strict was newly established by affixing “A”. “G” of the usage classification was affixed to the materials whose defect control was further necessary from among materials with A and they were positioned in the grade of the best class of surface quality and defects as AG. Although some strict surface materials were actually operated as the materials with G, the symbol was set again in this revision while securing consistency with cold rolled steel sheets (NES M2020).
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M2021 [2009-1] (6) Addition of lubricant classification Because recently pressing working oil was abolished, application of solid lubricant was abolished and high lubrication antirust oil for which formability was placed higher priority was expected to be adopted thereafter for the purpose of downgrading, etc., the materials were newly established by affixing “L” this time. (7) Addition of classification for dimension control (Q) to classification by size The specification of “Q” in which sheet thickness dimensional tolerance of the lower limit side was strict was added to the classification by sheet thickness control from the viewpoint of optimum design. Ex. SP211Q t2.0 (coil width 800) → Sheet thickness of the lower limit is 1.80 and sheet thickness of the upper limit is 2.20 according to sheet thickness dimensional tolerance corresponding to pertinent sheet thickness and sheet width in Table 9-2. Lower dimensional tolerance of thickness becomes strict and equals tolerance – 0.16 (based on the formula described in the remarks of Table 9-2). (8) New establishment of high-speed strength of deformation Tensile strength by the high-speed tensile test was newly established as the substitute characteristic of absorption performance at collision. This strength standard was set based on the Nissan Research Center’s results measured by the high-speed tensile test of the One-bar method. Assurance by steel manufacturers is conducted as the process approval test. However, “The evaluating method shall be established in a separate NES section.” is described in the text, but the method is decided between the Materials Development Department and steel manufacturers for the time being. Concretely speaking, a crosscheck is performed between measurement values by Nissan One-bar method high-speed tensile test and measurement values by steel manufacturers’ evaluation facilities and manufacturers’ assurance values are decided, if necessary. (9) Regarding deletion of conventional units The conventional units that were described with the SI units in this Standard as reference were deleted because description of the unit system was changed from “description of conventional units with SI units as reference” to “description of SI units only” along with transition of phase 3 of SI unit. Outline of standard for 590 MPa class high tensile strength steel (cold rolled, hot rolled, GA) This revision was made for cold rolled, hot rolled and GA steel sheets together, and the outline was shown. GA steel sheet (hot GA steel sheet (cold Hot rolled steel Cold rolled steel rolled base sheet) rolled base sheet) sheets sheet (M2027) (M2027) (M2021) (M2032) SP254-590 TRIP steel SP154-590 No standard *1 No standard *1 New (1.4 min.) (Superior formability) SP793-590 Dual Phase (DP) steel SP253-590 SP153-590 SP783-590 New (1.6 min.) (Low yield ratio type) Revised (1.4 min.) Precipitation strength steel SP151-590 No standard No standard *2 No standard *2 (General use) Notes *1) Standardization is not planned for the time being because manufacturing is technically impossible. *2) Standardization is not planned for the time being because pressing forming is expected to be difficult and applicable parts are severely limited.
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M2021 [2009-1] Material selection flow of 590 MPa class high tensile strength steel The selection flow when engineering designers study application of 590 MPa high tensile strength steel is shown below. Start of study
Naked steel sheet or antirust steel sheet?
Is applicable plate thickness is t ≥ 1.6?
Antirust steel sheet?
Naked steel sheet
No
(After this, select based on material cost.)
Is applicable plate thickness t ≥ 1.4?
Yes
SP793-590 (GA hot rolled DP) (For details, refer to the material selection flow of M2027.)
SP783-590 (GA cold rolled DP)
SP253-590 (Hot rolled DP) If formability is NG, is a shape change possible?
No
No
SP254-590 (Hot rolled TRIP)
Yes SP153-590 (Cold rolled DP) If formability is NG, is a shape change possible?
No
Shape change
SP154-590 (Cold rolled TRIP)
Yes Shape change
Items to be noted in steel type change If the steel type is unavoidably necessary to be changed, pay attention to the following points. (1) A change from SP253-590 (hot rolled DP) to SP254-590 (hot rolled TRIP) is possible because performance such as pressing formability, yield strength, etc. does not reduce. (2) On the contrary, a change from SP254-590 (hot rolled TRIP) to SP253-590 (hot rolled DP) requires an agreement between the parties concerned because of reduction of performance mentioned above. A change from SP154-590 (cold rolled TRIP) to SP153-590 (cold rolled DP) is also similar to the case mentioned above. Others All materials newly standardized are not corresponding to the JFS standard as described in “Major points of ANNEX” at the beginning, and there are small actual results of mass production. Mechanical properties are set in this background and problems such as difficulty in pressing formability, etc. may occur in the case of current elongation values. Then, for mechanical properties, standards are planned to be revised in a year when actual result data of mass production is accumulated. Supplementary explanation regarding each item Item 5 Surface finish classification The 3 types of “As hot rolled (Finish leaving surface as forged : no symbols)”, “Pickling finish (P)” and “Shot blast roll finish (S)” were established. Item 7 Standard size and dimensional tolerance 1. For coil width, it is desired to avoid width less than 550 that is disadvantageous in terms of costs. 2. For thickness tolerance, corresponding tolerance revision (accuracy improvement) of the JIS standard was reflected. Item 12 Notation of symbols The order of description of each symbol was specified.
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M2021 [2009-1] Item 14 Report Departments to which the report about the change in the manufacturing process of steel sheets, etc. was submitted were changed to the Material Department, Production Engineering Department and Material Development Department of Nissan Motor Company along the current condition.
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