A532 Class III- high Cr white cast iron

[HakiNoir]

Hi folks,

I am writing a spec for purchasing A532 Class III high Cr white cast iron as the A532 is very general and I want to restrict the hardness and ITP requirements. What specific requirements you would put in the spec for this material? I know the general ones for casting but looking if there is any specific important ones for High Cr cast irons?

Thanks!

 

[arunmrao]

Amount of retained austenite, is important apart from amount of pearlite in microstructure.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[HakiNoir]

Thanks Arunmrao.

We are trying to go with 30% Cr. I would expect martensitic matrix with CrC precipitates in the hardened and stress relieved condition. What is the acceptable retained austenite/pearlite for that? Of course if I need more corrosion resistance than wear, more Cr is needed in matrix which might alter the retained austenite. Please correct me if I'm wrong.
Also, as this would be used in erosion-corrosion application, I am wondering if is it practical to have a carbide size requirement?

 

[EdStainless]

If you aren't careful you will double the price of your castings.
A little restriction on the chemistry, SR process, and a reasonable RA limit should do everything that you need.

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P.E. Metallurgy, Plymouth Tube

 

[HakiNoir]

Ed, thanks for your input. Any recommendation on those?

 

[arunmrao]

I agree with Ed's comments. Restrict Si content, finer grain size if possible, defect free castings and certainly secondary carbide precipitation. You might want to refer to old literature from Climax Moly and AFS publication edited by AFS " Abrasion Iron Castings" edited by Rick Gundlach et al.

"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.