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Assignment 8 - Stainless Steel
Problem 1
Q: What properties are required in the making of a stainless steel to make it qualify as stainless?
A: A minimum of 10.5% chromium is needed it the production of stainless steel.
Problem 2
Q: Type D2 tool steel contains 12% chromium; does this qualify D2 tool steel as stainless?
A: D2 steel is not classified as a stainless steel even though it has grater then 10.5%
chromium content. This is because D2 steel has a higher carbon content and other alloy’s in
addition which prevents passivity.
Problem 3
Q: Name the basic ferritic, austenitic, and martensitic stainless grades and state their composition.
A: The basic stainless grades and composition are:
* Ferritic - Cr 17% used in elevated temperatures and non-rusting parts. Type 430
* Austenitic - Cr 18% Ni 8% used in products needing a chemical resistance. Type 302
* Martensitics - Cr 12% used for non-rusting tools and structural parts. Type 410
Problem 4
Q: Name the free machining stainless steel alloys.
A: Stainless steel alloy types are, Type 303, Type 400 Series, Type 416, and Type 430F.
Problem 5
Q: Name the stainless steels that are un-weldable.
A: Type 440 family of stainless steel are unweldable.
Problem 6
Q: Name three chemical environments that will cause rapid corrosion of any stainless steel?
A: Hydrochloric Acid, Hydrofluoric Acid, and Bleaches.
Chemistry and Chemical Engineering key words: carbon steel, stainless steel, corrosion, chemical,
steel family, acid, rust, machine, grades, chromium, martensitic, ferritic, austenitic.
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