stress relieve Al alloy 2

[lidbasky]

Hi,
Is it usual to stress relieve an A356-T6 Al ring that cut & rough turned from tubular casting?
If it should be done, what is its temperature?

 

[swall]

The usual course of action when high dimensional stability is needed is to go to a T7 heat treat. For a 356 sand casting, perform normal solution treatment at 1000F for 8-12 hours, then water quench. Age at 440F, as opposed to the typical ageing temp of 310F. An alternate would be a T71 treatment at 475F. The normal "stress relief" for aluminum is in excess of 650F, which obviously would destroy your T6 properties.

 

[lidbasky]

I afraid that the part became overaged after stress releive treatment and cause tensile strength that we obtain by T6 temper (over 230 Mpa)became lesser than what is specified in standard.

 

[AndyVictor]

Thank you for these postings. I am not a metallurgist. Can you provide some guidance as to the source for these information (Such as heat treatment procedure for various metals and its effect on the metal for each case!!)on heat treatment metallurgy for a non metallurgist.

Regards

 

[CoryPad]

The ASM Handbook series, available from ASM International:

http://www.asminternational.org