SYS862-1/Autumn 2014 Practical project Group 3 Amir Keyvan Edalat Keivan Heydari Mahdi Masoumi 1 1

Outline  Overview of project  Experimental methods  Experimental results  Physical properties  Chemical properties  Metallography  Grain boundary  Microstructure  Conclusion 2

Overview of Project  Material identification  Material properties  Microstructure  Manufacturing method  Applications 3

Experimental Methods  Visual observation  Physical properties  Macro hardness  Chemical composition  Energy dispersive X-ray spectroscopy (EDX)  X-ray fluorescence (XRF)  Microstructure  Optical microscope  Scanning electron microscope(SEM) 4

Visual Observation  Rectangular shape (75.7*43.7*19.1 mm) 5 Code b4a2  Surface view  Side view Effect of spark

Physical Properties  Light gray color  Density = 7,75 gr/cm 3  No damping of noise  Attracted by magnet 6 Ferro alloy Not a %100 Austenitic Steel Steel

Macro Hardness TopSideHeight Hardness(HRC) 33,633,432,6 33,5 34,9 32,932,833,2 Average33,333,233,5 Standard deviation0, ,  Same hardness value in all direction 7

Chemical Composition  SEM – EDX  Confirms AISI P20 Steel 8

Chemical Composition  XRF analysis 9 The XRF result. SiNiCuMoVMnCr Average Standard Deviation  Suggested material based on derived composition  ASTM A681  Grade AISI P20  Conventional P20 does not have Vanadium

Microstructure  Optical microscope  To be sure our observation consider grains in all dimensions  Different agents used to reveal the grains:  Nital 3%  Picral  Valeila  Kalling  Specific agent ( 90 ml boiling distilled water, 10 g picric acid, Two drops of Zephiran chloride ) which proposed by “Mokhtar Ben Salah” Master student of ETS 10 Side Top

Microstructure  Nital, Picral, Valeila and Kalling are not reveal grains boundary The pictures below show sample that etched by Nital3% 11 Etched by Nital3% 500X 1000X

Microstructure Specific agent  Keep in 60 °C (to avoid crystallization of picric)  Etching time: 60s  No difference between grains in specimen Top and Side  Grains are not stretched 12 Top Side

Conclusion  In material composition vanadium added by manufacturer for a special purpose.  Precipitate the vanadium-rich carbides  Refining of grain growth austenite  Further structure also will be fine  Increase strength and toughness 13 Etched by Kaling

Conclusion  Possible applications:  Plastic injection molds( )  Compression molds  Rubbers  Fibre glass renforcements  Composites,… 14

 Grains are not stretched 15 Conclusion Cold roll Casting Hot roll Forge

Conclusion  Sample hardness: 33HRC  P20 Usually quenched and tempered  Proposed range for tempering of AISI P20 is 480 ̊ C to 595  Tempered in >600 ̊ C or long term(maybe sample part from core) 16 Ref:Chandler, H., Heat Treater's Guide: Practices and Procedures for Irons and Steels. 1994: ASM International

Thanks for all your attentions Questions/Comments? 17