SYS862-1/Autumn 2014

Practical project Group 3

Amir Keyvan Edalat

Keivan Heydari

Mahdi Masoumi

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OutlineOverview of projectExperimental methodsExperimental results

Physical properties Chemical propertiesMetallography

Grain boundaryMicrostructure

Conclusion

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Overview of Project

Material identificationMaterial propertiesMicrostructureManufacturing methodApplications

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Experimental MethodsVisual observationPhysical properties Macro hardness Chemical composition

 Energy dispersive X-ray spectroscopy (EDX)X-ray fluorescence (XRF)

Microstructure Optical microscopeScanning electron microscope(SEM)

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Visual ObservationRectangular shape (75.7*43.7*19.1 mm)

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Code b4a2

Surface view

Side view

Effect of spark

Physical Properties Light gray color Density = 7,75 gr/cm3

No damping of noise Attracted by magnet

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Ferro alloy

Not a %100 Austenitic Steel

Steel

Macro Hardness

  Top Side Height

Hardness(HRC)

33,6 33,4 32,6

33,5 33,5 34,9

32,9 32,8 33,2

Average 33,3 33,2 33,5

Standard deviation 0,309121 0,309121 0,974109

Same hardness value in all direction

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Chemical CompositionSEM – EDX

Confirms AISI P20 Steel

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Chemical CompositionXRF analysis

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The XRF result.

Si Ni Cu Mo V Mn Cr

1 0.1531 0.4316 0.1464 0.5077 0.1981 0.99 1.7965

2 0.1864 0.4409 0.1175 0.5122 0.1708 0.8857 1.8297

3 0.1616 0.4182 0.1532 0.5025 0.1459 1.0055 1.8177

Average 0.167033 0.430233 0.139033 0.507467 0.1716 0.9604 1.814633

Standard Deviation 0.014127 0.009317 0.015477 0.003963 0.021318 0.053199 0.013726

Suggested material based on derived composition ASTM A681

Grade AISI P20 Conventional P20 does not have Vanadium

MicrostructureOptical microscope

To be sure our observation consider grains in all dimensions

Different agents used to reveal the grains:Nital 3%PicralValeilaKallingSpecific 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

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Side Top

Microstructure Nital, Picral, Valeila and Kalling are not reveal grains

boundary

The pictures below show sample that etched by Nital3%

11Etched by Nital3%

500X 1000X

MicrostructureSpecific 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

12Top 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

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Etched by Kaling

ConclusionPossible applications:

Plastic injection molds(https://www.youtube.com/watch?v=eOr-lpny13U)Compression molds

RubbersFibre glass renforcementsComposites,…

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Grains are not stretched

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Conclusion

Cold roll Casting

Hot roll Forge

Conclusion

Sample hardness: 33HRCP20 Usually quenched and temperedProposed range for tempering of AISI P20 is 480MC to 595

Tempered in >600MC or long term(maybe sample part from core)

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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