Recommendation? Quenching speed structural differences?

M

Mstrick96

Joined
Mar 6, 2018
Messages
28
I've been studying the quenching speeds of steels and the resulting metallurgical characteristics. I have a couple of questions.

Is the goal of quenching always to try to get as close to all martinsite as possible? Or are there reasons why I might want to select a slower speed quenchant to end up with a martensite/bainite blend? Or even have some retained austenite?

From what I've read, it's possible to design a quenching profile to end up with a 50/50 blend or whatever. I just haven't seen why I might want to do that.
 
Yes! Bladforums.com and knifesteelnerds.com are becoming my two favorite sites.

From the referenced paper, it looks like getting the most out the bannister vs martinsite issue requires controlled molten salt bath quenching systems. I'm also interested in the properties that more common quenchants can produce. Especially in blends.
 
If you are not holding at bainite formation temperatures, I can't imagine a reason you would want less than full hardness out of the quench. The only thing you might be able to do with playing with speed is get differential hardness without clay or an edge quench. I remain unconvinced that differential hardening has any non visual advantages over differential tempering, so I would probably not bother. Just use a quenchant that is fast enough for your steel.
 
1084ttt.jpg
What has gotten me to thinking along these line is that some of the ttt diagrams I've seen make it look like the required quench speed is almost impossible to achieve if the goal is to get tot he left of the "nose". Like this one for 1084. Looks like it needs to be under a second? If I can't get a fast enough quench,what does slower do to the steel?

I must be missing something.
 
Thanks, Larrin!
That's helpful. It sounds like the ttt diagram is more useful if I am interested in producing bainite, while the CCT curve is more useful for transforming to mostly martinsite.

Lots to learn!
 
A member here offered up a salt pot for someone to do some testing with bainite. Whatever came of that?
 
Salt pots are on order and the testing should start this fall. Evenheat is building a special low temp salt pot for this project.
 
You must log in or register to reply here.
Back
Top