8620 yield v. temperatureI 1

[mikerock]

I am caught without books.....and was asked:

"I recently read a paper that said; AISI-8620 has 85,000 psi yield strength
at room temperature but at 650*F it drops to below 30,000-psi yield
strength. Is this true?
ED"

Thank you,
Mike

 

[metengr]

No. However, what do you think?

 

[tbuelna]

mikerock,

If your 8620 alloy steel part was quenched and then tempered at a temperature below 650degF, then continued exposure above 650degF will essentially re-temper your part. An 8620 steel part tempered at 650degF would still likely result in an Fty well above 30ksi.

According to MIL-HDBK-5, the Fty at 650degF of a low-alloy steel like 8620 only drops to about 75% of RT properties (ref. fig. 2.3.1.1.1).

Hope that answers your question.
Terry