1075 heat treatment

[Gerhard Gerber]

Do you mean some anti-scale compound so I can normalize in the kiln?

I don't have any refractory cement, and I'm careful about what I put in the kiln because I can't afford to replace it.
I try to get at least 2 uses out of each foil envelopes, so I considered using one of those for the 1070 blades, but I mostly make hunting knives in stainless and chef's knives in 1070, so the envelops are too small.

 

[Alan Longmire]

No, I meant in the forge.  I agree about putting odd things in the kiln.  If you have some protective atmosphere in the forge you can do all the pre-quenching heat treat steps with no worries about decarb.

[Gerhard Gerber]

Chicken & egg situation, if I could get my new burners working I could build the new forge with the proper bricks I acquired nearly 2 years ago and stick a pipe in there.....

Been thinking about this a lot seeing the price of kilns, before I've imported it....

Shouldn't say this out loud, but I'm pretty sure I got lucky a few times and did a better HT with a pipe in the forge than with the accurate kiln, specifically carbon steel blades......way less decarb.

 

I have a small container of something that might be water damaged refractory cement, I could never get it to set into anything usable so I might as well try the mix you suggested, can't hurt and no loss 

Edited January 12, 2022 by Gerhard Gerber
grammer

[Alan Longmire]

Certainly worth a shot.  Use a coat thin as paint.

[Doug Lester]

Is Parks #50 the preferred quenchant for 1075?

 

Doug

[Alan Longmire]

If it's the NJSB low-Mn 1075, yes.  That or water/brine, it was developed for hamon.

 

If it's Admiral or other high-Mn 1075, no. Canola or a medium oil is better.

[Randy Griffin]

I have a piece of 1075 from NJSB so when I use it I will need to quench in water to get the most out of the steel?

[Alan Longmire]

No, canola is fine.  Only use water if you want really active hamon or if it's really thick in section, like a hammer. 

[Gerhard Gerber]

I now have 1070, 1084 and 80CRV2 in thin bar stock suitable for kitchen knives.

The recommendation here is bar stock like that needs to be normalized as well, currently I just grind and heat treat.

I will still try the old refractory cement as anti-scale, but I have serious doubts I can get the stuff to bind.

So I had a thought, what if I profile the blade, normalize, grind the bevels and then heat treat?

[Alan Longmire]

5 hours ago, Gerhard Gerber said:

what if I profile the blade, normalize, grind the bevels and then heat treat?

 

That will work fine.  I'd throw one more normalizing cycle in after the grind just to relieve any uneven stresses from the grind.

[Bjorn Gylfason]

I'm wondering if anyone has experience with this thing I'm pondering.

 

I have a pretty long blade forged from 1075 and am more concerned with toughness than absolute hardness.

 

Would quenching it in medium speed oil help any with that or should I use the fast one and just temper it back?

[Alan Longmire]

Use the fast oil and temper it back.  The finer structure is tougher.