The mechanical properties on three samples tested are good with the exception that the elongation of one sample was under spec at 13.5% vs 16% and each sample was a bit soft at 28 HRC.
What would be the consequence of a low Molybdenum content in ASTM 4140, say around 0.01-0.02%? I'm using the steel in the B7 condition in a tensile application.
Thanks for your help.
I appreciate all the responses.
Since I sent out my first question, I have learned that coal mining can indeed create the right environment to bring on SCC in the 7075 aluminum alloy.
There are 10 tie rods on this machine, pinned in tension and statically loaded to 40% yield for 2 hrs / day...
wktaylor
Thank you for your reply.
Is it the sulphate salts produced by pyrite oxidation that destroy the alloy?
Will I be looking for sulfur in the crack zone under the SEM?
Is it possible to predict how quickly SSC will begin in my 2.5" thick machined part under heavy load?
Regards, Larry...
