Praktikum Metal 1 [PDF]

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TEKNIK MATERIAL DAN METALURGI FAKULTAS TEKNOLOGI INDUSTRI DAN REKAYASA SISTEM INSTITUT TENOLOGI SEPULUH NOPEMBER Sukolilo , Surabaya 60111Telp. (+6231) 5943645 , 5997026 , 70800753 Fax. (+6231) 5943645 , 5997026 E-mail :[email protected]



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ABSTRACT The experiment of Impact test is performed to know about resistance of a metal according to the impact load, the sensitivity and resistance of a metal due to the notch, and the effect of temperature to the impact load resistance of a metal.in this experiment, we use strip steel for the specimen, also use standards the ASTM E23 standard. There are three variances for the specimen experiment, from the dry ice temperature, without treatment, and from the boiling water temperature. There are also several tools that we used, like impact test machine, heater, miser, and clamp. To do the experiment, we must follow the step. First, we need to prepare the specimen and the tools that we will use. Put the specimen in to the dry ice until -20 0C and put the other specimen in to the boiling water until 90 0C. Then, put the test specimen on anvil and the notch must be positioned in the center in the direction of the pendulum's eye. Then, pull the pendulum until until the needle shows angle 1400. After that, release the pendulum until the pendulum hits the specimen. When the pendulum starts swinging after hits the specimen, we can stop the pendulum so that it is not dangerous. After the pendulum stopped, write the data for final angle of the pendulum. After performed the experiment, we can analyze the specimen and calculate the data to find the impact energy, the impact strength, and percentage fracture. The impact energy for specimen from dry ice is 39,00424 J, then for without treatment specimen 112,3082 J, and specimen from boiling water is 162,4511 J. For the impact strength values also from the specimen from dry ice, without treatment, and from boiling water are 0,3611 J/mm2 , 1,1344 J/mm2 , and 1,3885 J/mm2. And for percentage fracture percentage from the specimen from dry ice, without treatment, and from boiling water are 100%, 76,868%. And 85,47%.



Keywords: ASTM E23, Impact Test, Strip Steel



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TABLE OF CONTENTS ABSTRACT...........................................................................................................................................i TABLE OF CONTENTS.......................................................................................................................ii LIST OF PICTURES..........................................................................................................................iv LIST OF TABLE..................................................................................................................................v CHAPTER I..........................................................................................................................................1 I.1.



Background...........................................................................................................................1



I.2.



Problems................................................................................................................................1



I.3.



Experiment Objective...........................................................................................................1



CHAPTER II........................................................................................................................................2 II.1.



Steel........................................................................................................................................2



II.2.



Strip Steel..............................................................................................................................3



II.2.1.



Composition..................................................................................................................3



II.2.2.



Application....................................................................................................................4



II.3.



Impact Test...........................................................................................................................4



II.4.



Mechanical Properties..........................................................................................................5



II.4.1.



Strength.........................................................................................................................6



II.4.2.



Ductility.........................................................................................................................6



II.4.3.



Toughness......................................................................................................................6



II.4.4.



Modulus Resilience.......................................................................................................7



II.4.5.



Impact Resistance.........................................................................................................7



II.5.



Transition Curve..................................................................................................................7



II.6.



Ductile and Brittle Fracture.................................................................................................8



CHAPTER III.....................................................................................................................................10 III.1.



Flow Diagram..................................................................................................................10



III.2.



Materials and Tools........................................................................................................10



III.2.1.



Experimental Tools.....................................................................................................10



III.2.2.



Experimental Materials..............................................................................................10



III.3.



Treatment Table.............................................................................................................11



III.4.



Standard Test..................................................................................................................11



III.5.



Experimental Steps.........................................................................................................11



III.6.



Experiment Circuit.....................................................................................................11



CHAPTER IV.....................................................................................................................................13 IV.1.



Data Analysis..................................................................................................................13 ii



IV.1.1.



Experiment Result Table............................................................................................13



IV.1.2.



Impact Energy Calculation........................................................................................13



IV.1.3.



Impact Strength..........................................................................................................14



IV.1.4.



Percent Fracture Area................................................................................................14



IV.1.5.



FATT and Energy vs Temperature Curve...............................................................15



IV.2.



Discussion........................................................................................................................15



IV.2.1.



The Effect of Temperature on Impact Energy.........................................................15



IV.2.2.



Impact Strength..........................................................................................................16



IV.2.3.



Fracture Pattern.........................................................................................................16



IV.2.4.



FATT Curve................................................................................................................17



CHAPTER V......................................................................................................................................18 V.1.



Conclusion...........................................................................................................................18



V.2.



Suggestion...........................................................................................................................18



BIBLIOGRAPHY................................................................................................................................vi ATTACHMENT.................................................................................................................................vii



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LIST OF PICTURES Picture II.1.(a) Specimen used for Charpy and Izod impact tests.(b) Schematics drawing for impact test and Specimen placements for both Charpy and Izod tests.......................................5 Picture II.2. Schematic description of transition temperature...................................................8 Picture II.3. Brittle and Ductile Fracture...................................................................................9 Picture III.1. Flow Diagram of Impact Test............................................................................10 Picture IV.1. FATT Curve.......................................................................................................15 Picture IV.2. Fracture Pattern..................................................................................................16



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LIST OF TABLE Table II.1. Cold-forming strip steels..........................................................................................3 Table III.1. Heat Treatment Table...........................................................................................11 TableIII.2. Experiment Circuit of Impact Testing...................................................................11 Table IV.1. Impact Test Data Result........................................................................................13



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CHAPTER I INTRODUCTION I.1. Background During the period of use, a material usually receive various kinds of loading, one of which is shock load. Impact load is often defined as the load acting on a structure in a very short time, generally less than 1 second, even for only a few milliseconds. Some examples of impact loads are air pressure loads due to bombs, bullet shots, or collisions of objects on structures. The existence of this impact load will certainly have a more dangerous impact when compared to static loads such as in tensile tests, because the very fast strain rate results in very fast fractures. The initial test was developed in 1905 by the French scientist Georges Charpy and then the test was used during World War II, because of that, there were many brittle fracture phenomena that led to the welded joints of warships and their tankers. Among the fracture phenomena, some are partially broken and some are actually broken into two parts. This phenomenon occurs especially in winter, when ships are in the high seas or at anchor and it turns out that medium steel, which is usually ductile, can turn brittle when under certain conditions. One of the most famous cases was on the Titanic, when the Titanic collided with an iceberg, the steel hull and wrought iron rivets failed due to the brittle reclaim. A type of catastrophic failure in the structure of a material, fracture that occurs without prior plastic deformation and at very high speeds. Causes of fracture include low temperature, high impact loads and high sulfur content. On the night of the Titanic disaster, each of these three factors emerged: The water temperature was below freezing, the Titanic was traveling at high speed when it hit an iceberg, and its steel hull contained high levels of sulfur, which would make the steel structure a more fragile. Therefore,it is very important to do an impact test on the material, and currently every material to be used in various engineering fields in general, one of which really needs to go through an impact test in order to meet good safety standards. mpact tests are used in studying the toughness of material. A material's toughness is a factor of its ability to absorb energy during plastic deformation. Brittle materials have low toughness as a result of the small amount of plastic deformation that they can endure. To know the factors of impact testing result,The kind of impact tests will be studied through this experiment. I.2. Problems Based from the background above, the problems of this experiment are as follow: 1. How does the resistance of a metal according to the impact load? 2. How do the sensitivity and resistance of a metal due to the notch? 3. How does the effect of temperature to the impact load resistance of a metal? I.3. Experiment Objective From the experiment problems above, the objectives of this experiment are as follow: 1. To know about resistance of a metal according to the impact load. 2. To know about the sensitivity and resistance of a metal due to the notch. 3. To know the effect of temperature to the impact load resistance of a metal.



CHAPTER II REVIEW OF LITERATURE II.1. Steel Steel is an alloyed metal with iron as a basic element and carbon as its main alloying elements. Carbon content in steel ranges from 0.2% to 2.1% by weight according to grade. Function carbon in steel is an element hardener by preventing dislocation shift on the crystal lattice (crystal lattice) of atoms iron. Another common alloying element added besides carbon is manganese (manganese), chrome (chromium), vanadium, and tungsten. (Arifin: 2017:1) Steels are the most complex and widely used engineering materials because of the abundance of iron in the Earth’s crust, the high melting temperature of iron (15348C), a range of mechanical properties, such as moderate (200–300 MPa) yield strength with excellent ductility to in excess of 1400 MPa yield stress with fracture toughness up to 100 MPa m-2, and associated microstructures produced by solid-state phase transformations by varying the cooling rate from the austenitic condition. (Totten, 2006:14) Steels can be classified by their carbon component. In general, carbon steels contain up to 2% total alloying elements and can be subdivided into low-carbon, medium-carbon, highcarbon, and ultrahigh-carbon (UHC) steels. Low-carbon steels contain up to 0.25% C. The largest category of this class is flat-rolled products (sheet or strip), usually in the cold-rolled or subcritical annealed condition and usually with final temper-rolling treatment. The carbon content for high formability and high draw ability steels is very low (