Quench cooling rate and finished martensite percentage relation for high alloy steel.

[shqxk]

Talking about the steel that has very long pearlite nose like most air hardening steel. D2 or CPM-3V for instance. Will the faster quench yield higher as-quench hardness?

I know the another benefit of faster quench is to avoid Cr carbide precipitating at grain boundaries but would the faster quench like oil/plate quench give higher volume of as quenched martensite compare to quenching in still air?

 

[Nathan the Machinist]

Talking about the steel that has very long pearlite nose like most air hardening steel. D2 or CPM-3V for instance. Will the faster quench yield high as-quench hardness?

I know the another benefit of faster quench is too avoid Cr carbide precipitating at grain boundaries but would the faster quench like oil/plate quench give higher volume of as quenched martensite compare to quenching in still air?

Yes, I believe it does. This would be due to higher strain energy going into Mf, which would give you a more complete conversion. Mind you, that conversion was probably going to happen anyways during/after temper, but I believe that converting during the primary quench leads to structures that play better with each other, at least in those two alloys.

RA does not just convert into martensite, and martensite that forms after-the-fact might be less cohesive to the rest of the matrix. Though I'm not sure. Pinging Mete!