Plate quenching?

E

Everglade Blade

Joined
Apr 5, 2013
Messages
63
I need some help, I've been making knives for a couple of years and now I want to try and use another steel. I'm looking at A2, I do my own heat treating, I have a good programmable oven. I want to know how exactly to use the plate quenching method? Any help would be greatly appreciated, also any good A2 ht methods I won't turn down :D
 
This is what I do and it works pretty well for me.
I use 3x1x12 aluminum stock as quenching plates.
Finish to 600 grit and double foil wrap, put in oven while it's cold, spine down, tang towards door.
Ramp to 1200 hold for 5-10 min., ramp to 1500 hold for 5-10 min., ramp to 1775 hold for 20-25 min.
I clamp the bottom plate hanging over the edge of the table right next to my oven, as soon as the oven has done its thing I put on welding gloves grab some pliers and take the knife out quickly but carefully, so as not to bump it into anything, place it spine down on the bottom plate turn it onto its side and quickly sandwich it between the top and bottom plates. I hold it with a spring clamp for about a minute.
Then cut open the foil, check for warp, test hardness and temper immediately.
When I dry ice treat them, if I remember correctly, 450 degree double temper gave me 60 HRC. And without dry ice I think I got 59 HRC with a 400 degree double temper.
 
Thank you so much, I've been wanting to try a2 for a while, I mostly do O1. Thanks for the help,now I need to order some and try it.
 
I've tried a couple of different recipes for A2, the one I liked the best was actually an air-quench recipe.

Coat in anti-scale compound (I used ATP641)
Preheat to 1100ºF, equalize
Ramp to 1775ºF, hold for 35 minutes
Quench in still air to below 150ºF
Temper at 400ºF, 2 hours
Sub-zero treatment in dry-ice & isopropanol for 20 minutes
Temper at 400ºF, 2 hours

Final hardness: 59.5HRC

This recipe is optimized for a really tough blade though, so other recipes may get better edge retention.

I also did some oil-quenched A2 with sub-zero before the temper cycle. It was considerably harder (64HRC @ 400ºF temper), took a noticeably finer initial edge but didn't seem to hold it any longer when cutting things like cardboard. It might be better for cutting softer materials like foodstuffs or for a skinning knife, but the air-quench version was my favorite overall.
 
Yeah, I followed your testing tread, ( thought it was great, very precise) and that's what got me into doing a A2 knife. I had been thinking of trying A2 for awhile,then once again after reading your tread, I'm looking again.
 
Everglade Blade said:
So, you just pull it out of the ht oven and let it hang? Is that air quenching?
Click to expand...

Yes, that was what I was doing... Most 'air quenched' steels these days are 'positive pressure' quenched, which is where they inject an inert atmosphere into a vacuum furnace. Cooling in regular air works fine too as long as the steel is protected from oxygen.
 
You must log in or register to reply here.
Back
Top