improving quench results

[wnease]

I am experiencing warpage with steels that need faster quenches. Is there anything that can be done as a pre-treatment to reduce the need for such a fast quench to reach full hardness? For that matter, getting a blade harder in the quench without increasing the speed of the quench would also seem to be advantageous.

Other option is to switch to air hardening steel...

 

[richard j]

when you quench are you going in tip first and straight down? do you move the blade any after its in the oil?

 

[wnease]

42" sword blades... zero chance of symmetrical entry into the quench unfortunately

 

[wnease]

from Kevin, "If, however you just normalized the steel instead of spheroidizing it, the entire grain will be filled with fine alternating lamellae of iron and carbon which will mix together evenly much quicker. Thus shortening soak time, but also tearing up your tools much worse since wide sheets of carbide are a bit more immovable than tiny beads of carbide. The shortest soak times, if any, will be needed when heating a hardened piece of steel since the carbon is already in solution from being trapped there in order to harden the steel. But this is also not set in stone since much will depend on the rate of heating"

Just wondering if maybe multiple quench cycles increase the percentage of martensite formation while shortening soak times, keeping expansion uniform and reducing warpage...

... or maybe all the warpage is thermal distortion from uneven heat loss? But shouldn't it return to original proportions when temperature equalizes?

???

 

[richard j]

when you put your blade in the oil, is it going in with the blade tilted to one side or the other?

 

[Kevin R. Cashen]

...

Just wondering if maybe multiple quench cycles increase the percentage of martensite formation while shortening soak times, keeping expansion uniform and reducing warpage...

No. Going into a hardening operation with residual stress from a previous heat treatment without any stress relief will increase distortion. If you want to deepen the hardenability of the steel you can increase your soak temp, but there is a fine line between more complete solution and grain growth. Watch how you go into the oil, if it is a double edge sword do all of your quenching point down. Make some practice bars that approximate your blades and learn the cooling rate of your quenchant in counted seconds. Learn to interrupt at around 450F and then with gloved hands keep the blade straight as it cools to room temp.