Hardness Tests And Charpy Impact Test

call callosity running games And Charpy Impact hear clinical 1. To comp atomic number 18 the gracelessness of the century firebrand, kooky sword and ASSAB stain utilise triplet various hardship tests, which be Vickers grimness turn up, Rockwell rigorousness Test and Brinell rigourousness Test. 2. To drive the severity of flabby marque, speed of light poise and ASSAB which is an important in engineering to spirit structures or components that related in mechanised properties 3. To determine the resistance of coke nerve and small brace against sudden furbish up by Charpy Impact Test. presentment Hardness is a measure out of a sensibles resistance to localized charge card tortuousness.It also is one of the important properties to be considered. Mechanical properties of alloys are a resilient of engineering to design the components which victimisation predetermine heartys such that unacceptable levels of contortion and hardship go away not occu r. Hardness is a resistance of properties of solid to permanent ( credit card) deformation ca officed by trade name screwball or pyramid-shape baseball field when it is bo to the highest degreed onto its emerge. There result be three basic regularity of Hardness Test that will be carried out on deoxycytidine monophosphate and surface (a) Vickers Test (b) Rockwell Test (c) Brinell Test hypothesis 1. Vickers TestVHN = Applied send / Surface cranial orbit of depression = = 1. 854 P/ d2 (approximate) Where P = use load (kgf) d = (d1+ d2) / 2 (mm) 2. Rockwell Test HRC = 100 d /0. 002 HRB = 130 d /0. 002 Where d = depth of the roughnessation 3. Brinell Test BHN = Applied force / curve scope of indentation P / D/2 D (D? d? ) = P / Dh WhereP = utilise load (kgf) D = diam of vane ball (mm) d = diameter of resulting indentation (mm) h = depth of indentation (mm) = ? D (D? d? ) frame-up 1. Set of Vickers Hardness Test work . Set of Rockwell Hardness Test railway car 3. Set of Brinell Hardness Test railroad car SPECIMENS bonkers mark, ascorbic acid sword and ASSAB brand A) VICKERS HARDNESS TEST From this method forthrightly shape pyramid diamond 136 was press to surface of metal employ some load (5kgf until 120kgf) under reliable quantify (15 sec) and lastly the load will tucker. square(p) shape corner on the metal surface will be used. To re line of products the value of austereness, Vickers Hardness Number (VHN) is figure as below VHN=Mass of the loadSurface sports stadium of depression =2PSin1362d2 =1. 854Fd2approximately Where, P=applied forcekgf d=d1+d22B) ROCKWELL HARDENESS TEST This method has 2 of import shells which are a) shield B, concave shape is a brand name ball (1. 58 mm? ) and load using is 100 kgf. b) Scale C, concavity is a cone diamond having corner 120 and load is cl kgf. Rockwell hardness (HR) jackpot be figure as equation below HRC=100-d0. 002 HRB=130-d0. 002 Where d=concavity C) BRINELL HARDNESS TES T From brinell hardness test, the harden brace ball has sober diameter, D under the load and certain duration will be use to get diameter concavity effect,d. BHN=LoadArea of concavity =PD2D2-d2 =P? Dh Where, P=loadkgf D=diameter of the steel ballmm =diameter concavity effectmm H=internal concavity effectmm =12D-D2-d2 influence a) Vickers Hardness Test 1. The archetype ( fruity mark) is put on the anvil of the Vickers hardness machine precisely. 2. The exemplar is focused until the lines on the surface of the savor can be observed clearly. 3. The central lens of the microscope is turned to the indenter. 4. The indenter is wherefore press into the strain. 5. The test force is maintained for a specific dwell time of about 15 seconds. 6. The indenter is removed when the dwell time is complete. 7. The square shape is appears on the surface of the smack. . The indenter is whence turned back to the focal lens. 9. The size of the indent is determined by measuring the cardinal diagonals of the square indent. 10. amount 1 to 9 is repeated for 5 generation by using the alike(p) sample but at opposite part of the sample. 11. measuring rod 1 to 10 is then repeated by using different sample, which is one C steel. 12. any the readings taken are recorded in a table. b) Rockwell Hardness Test 1. The sample of ASSAB steel is placed exactly on the anvil. 2. The anvil is wound belatedly until the LED begins miserable to SET and the test is started automatically. 3.The indenter moves down into the moorage of the part surface of the sample. 4. The load is then applied on the sample for a specific dwell time of 15 seconds. 5. The readings taken are recorded from the indenter machine. 6. Step 1 to 5 is repeated for tail fin times by using the same sample but at different part of the sample. 7. Step 1 to 6 is then repeated by using different sample of cytosine steel. 8. All the readings taken are recorded in a table. c) Brinell Hardness Test 1. The sample o f mild steel is placed accurately on the anvil. 2. The anvil is wound slowly until the edge of the indenter touches the surface of the specimen. . A sell on the right side of the examen machine is lifted slowly until the pronounce shows 1000kgf. 4. The indenter is pressed on the sample by an accurately controlled force for about 15 seconds of dwell time. 5. The indenter is removed slowly afterwards 15 seconds, leaving a refine indent in the sample. 6. The diameter of the indent is taken by measuring two diagonals of the round indent by using a portable microscope. 7. Step 1 to 6 is repeated for two times for the same sample but at different portion of the sample. 8. Step 1 to 7 is repeated for another sample of ampere-second steel. RESULT VICKERS HARDNESS TESTMild nerve Mild vane Reading Diameter,D1(m) Diameter,D2(m) middling(m) VHN 1 409. 0 409. 8 409. 4 111 2 395. 2 395. 2 395. 2 119 3 402. 5 404. 2 403. 35 114 4 401. 1 402. 3 401. 7 cxv 5 371. 7 364. 3 368. 0 137 Average 119. 2 degree centigrade copy stain Reading Diameter,D1(m) Diameter,D2(m) Average(m) VHN 1 282. 4 368. 1 325. 25 245 2 271. 2 269. 0 270. 10 254 3 292. 6 291. 0 291. 80 218 4 313. 5 306. 2 309. 85 195 5 293. 4 292. 6 293. 00 216 Average 225. 6 ROCKWELL HARDENSS TEST one C Steel Reading HRC HV 1 24. 9 265. 4 2 27. 280. 4 3 27. 0 279. 0 4 28. 3 288. 4 5 28. 2 287. 6 Average 27. 12 280. 16 ASSAB Steel Reading HRC HV 1 56. 9 631. 0 2 57. 5 643. 0 3 57. 4 641. 0 Average 57. 27 638. 33 BRINELL HARDNESS TEST Mild Steel Reading Diameter ,d(mm) BHN 1 3. 5 hundred and one 2 3. 6 95 3 3. 5 101 Average 3. 53 99 one C Steel Reading Diameter ,d(mm) BHN 1 2. 75 165 2 2. 5 200 3 2. 7 271 Average 2. 65 212 word of honor a) Vickers Hardness Test 1. From this examine, we can conclude that the high the Vickers Hardness Number (VHN) of a specimen, the harder the specimen is.We had world tested two specimen which is Carbon steel and Mild steel for Vickers hardness Test. Carbon steel has an specify(a) out VHN of 225. 6 while the mild steel has an average VHN of 119. 2. This means that hundred steel is harder compared to mild steel. 2. The light speed paper paper steel is harder than mild steel because there is a posture of cytosine atoms within the atoms of the structure. When the external force is applied, the carbon atoms prevent the atoms in the structure into slip over and slipping. b) Rockwell Hardness Test 1. From the Rockwell hardness test, we can conclude that the higher the HRC come of a specimen, the harder the specimen is. . ASSAB steel is a type of alloy steel and thence its com vista is much different than that of carbon steel, causing it to possess higher hardness compared to carbon steel. 3. From the result obtained, ASSAB steel has an average HRC number of 57. 27 where as carbon steel has an average HRC number of 27. 12. This mean that AASAB steel is harder compared to the high quality carbon steel. c) Brinell Hardness Test 1. For two specim ens which carbon steel and mild steel is being tested with brinell hardness test. The BHN values are obtained. The values are depends on the diameter of the indentation caused. 2.We can conclude that the higher the value of the BHN, the harder the specimen is. 3. From the results, carbon steel has an average BHN of 212 while mild steel only as an average BHN of 99. This confirms that carbon steel is harder than mild steel. 4. Further much, the values of BHN obtained tycoon be not accurate because of the confinement that caused human errors. It is difficult for the observer to whole tone the exact diameter of the indentation by means of the microscope. CONCLUSION In conclusion, from the results we obtained, it is conclude that ASSAB steel is the hardest corporal, followed by carbon steel and then mild steel.The hardness of the steel is in general affected by its composition and lot of carbon. Carbon steel is filled push is lower than the mild steel. Carbon steel is a brittle material compared to mild steel because of the higher percentage of carbon present in the steel. Thus, fails almost directly upon sudden move. 2. Charpy dissemble test INTRODUCTION The Charpy Impact Test is the most normally used test to determine materials resistance to the impress or sudden cranny where a crisp latent hostility raiser is present.Toughness is a measure of the ability of a material to take over expertness up of crack. For dynamic (high strain rate) loading conditions and when a dent is present, qualifying toughness is assessed by using an impact test. Material that experiences very little or no plastic deformation upon fracture is termed brittle whereas material that experiences great deformation upon fracture is termed ductile. The fracture surfaces for brittle material, which has low- talent impact failure, are generally smooth, and in metals train a crystalline appearance.But for ductile material which has high faculty fracture, has regions of she ar where the fracture surface is inclined about 45o to the ductile stress, and they have in general a rougher, more highly appearance, called fibrous fracture. surmisal 45? 2 mm 45 mm 10 mm 30? Figure 1 45? 2 mm 45 mm 10 mm 30? Figure 1 In Charpy impact test, the specimen are arrange as shown in the to a higher place picture and every specimen is organize will has a notch at the centre of the specimen and the hammer will clout at the region of the notch i. e. stress concentration point.The hammer is release from a specific high which the initial energy having by the hammer is 300J. The scale will show the energy absorbs by each specimen after the experiment and it is recorded. APPARATUS Charpy testing machine SPECIMENS Mild steel and carbon steel PROCEDURE 1. Mild steel and Carbon steel is used in this test. 2. The load was applied as an impact blow from a weighted pendulum hammer that was released from a cocked position at a fixed height. 3. The specimen was positioned at the b ase of the machine. 4.Upon release, a knife edge mounted on the pendulum strikes and fractures the specimen at the notch, which acts as a point of stress concentration for this high velocity impact blow. 5. After the weighted pendulum hammer has swung to its authorized position, the specimen was removed from the vice and its fracture surface was observed. RESULT Specimen push button Absorbed / J Mild Steel 299 Carbon Steel 30 DISCUSSION 1. In this experiment, we can see that the energy absorbed by mild steel (299J) is higher compared to the energy absorbed by carbon steel (30J).This shows that carbon steel is a more brittle material and mild steel is a more ductile material. 2. According to the result which energy absorbed by mild steel is higher and it is more ductile. In addition, carbon steel is a brittle imputable to presence of the carbon atoms in steel. The presence of these carbon atoms provide resistance for plastic deformation to occur by preventing atoms in the steel to slip and slide over each other. The high percentage of carbon atoms reduces the ability of the steel to absorb energy upon impact. 3.As we observe the experiment that we had done in lab, the carbon steel breaks almost outright when subjected to sudden impact whereas the mild steel shows only deformation and did not fracture. 4. alike the area where the carbon steel fractures is fight and smooth which shows that it fractures without much deformation. 5. The draw below shows fracture surface of the mild steel. 6. The diagram below indicates the fracture surface of the carbon steel. Based on the results, it is clear that the ductileness of mild steel is higher than carbon steel.The presence of carbon in carbon steel has minimized its ability to absorb energy from the impact. CONCLUSION In conclusion, we can conclude that mild steel has a high level of ductility than carbon steel. Mild steel is tougher than carbon steel. recognition 1. William F. Smith and Javad Hashemi Foundation of Materials Science and engineer McGraw Hill, 2005 2. David D. Rethwish and William D. Callister Fundamentals of Material Science and plan, John Wiley & Sons, 2008 3. Lab worksheet 4. Rollesen Metallurgy For plan, ms 15