Clarification about correlation of yield strength and hardness of a 8640 steel after heat treatment 2

[ZecaEng]

Dear all,

First of all I will describe my current situation.
I am starting an internship on a new company, I am still on my third day, but an accident happened and as I am the only one here who has any knowledge on materials the responsible engineer came up to me and asked me the following question:

"I am doing an FEA to investigate the cause of the accident and I want to know if there is a way to find out a table or any reference correlating the hardness of a 8640 steel with the yield and ultimate tensile strength after certain heat treatment, knowing the properties before the treatment and the hardness post heat-treating? Assuming that I know the heat treatment"

I know that is too little information, but it would be of great help if anyone could give any advice.

Matheus

 

[curiocity]

I did a quick Knovel search and think ASM Handbook, Volume 4 Heat Treating, section 13.4 might have some of the information you're looking for. Hope that helps!

 

[redpicker]

It really depends a lot on what the "certain heat treatment" was, or perhaps more percisely, how well it is defined.

 

[ZecaEng]

Thank you that was of great help!

 

[curiocity]

You're very welcome Matheus! I have a question too if you don't mind - I'm in the process of putting together some materials to help ramp up new engineers, and am curious as someone starting out, what type of information do you most urgently need to do your job, and what/where do you current look for that research and information?

 

[TVP]

Matheus,

ISO 18265 shows a number of hardness conversions and their approximate tensile strength for steels. For quenched and tempered steels in the range of ~ 22 to 60 HRC, the ratio of yield strength to tensile strength is in the range of 90-98%, with 90-95% being typical up to ~ 45 HRC and 95-98% for steels > 45 HRC. You can obtain ISO 18265 directly from ISO or from a licensed vendor such as IHS:

http://www.iso.ch

http://global.ihs.com