HAve you ever had steel that just wont harden as well as other batches?

blgoode

blgoode

Knifemaker / Craftsman / Service Provider
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Oct 3, 2003
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What I have been using is 0-1. I am getting it from pops or McMaster Carr. It seems like sometimes I get a little steel that just wont get that 100% brittle feel when quenched. And I know I had it hot enough......I think :D

Anyway, just throwing out the idea that some steels may vary....whats your experience?
 
I was just dealing with that a couple weeks ago with the last hawk I posted. Same steel out of the same bar. Finally bought some tranny fluid and got it to go but it sure had me scratching my head. Still don't know what was going on with it. It was 1084/95. Never had any problem with it hardening up before. Maybe it was just old steel........ :D
 
Throw a couple of them little blue pills in the quench. At least it will stay hard for a few hours anyway. Not speaking from experiance mind you.
 
WHat it does is more or less get hard but...not glass hard. I have sample pieces of different RC hardness 0-1 to judge by. When I quenched it it skated the file but not like brittle hard would. So I re HTed. same deal. The hardness to me would make a good chopper because it feels like its about 56 RC but I am trying to go for 58 to 59.

paring.jpg


Can you tell anything from the photo? Its the top one. ..The bottom one feels like 59 RC.
 
Dont know Brian. My problem with O-1 seems to be getting it soft enough Not to be brittle. I get the drillrod from toolandie.com
 
I knew I could count on the oldtimer to give me advise on hardness :o :D


I am using peanut oil at around 125 degrees. I wonder if quenching the previous blades raised the temp enough to effect the hardness. I may try it again and heat the oil to around 110 degrees. I'll let you know..........

Hope this one doesnt crack all up :D :D :eek: :eek:
 
I can really tell that threre is a fine line between too soft and being brittle in 0-1. Seems like my oven does better at tempering one blade, way in the back, at a time. I can tell if its near the front it doesnt get tempered as well and it has to go back in for one more ride.
 
When I switched from peanut oil to vet grade mineral oil, I got a whole lot more consistant results. For what it's worth. bruce
 
maybe I'll try that as well......I could just get the texaco type A like Ed Fowler recomends....
 
Try grinding some material off and then testing. What you may have is a layer of steel that has lost carbon and not got to full hardness. Gib
 
Gib - good idea!! I'll do that when I get to the shop this afternoon.....

Greg - ((((necessary quench speeds will increase as the grains get finer as a result of the pearlite nose of the TTT curve moving to the left.))))) IS he saying that a faster quench is needed i.e. lower quenching temperature??
 
I started having better results when I went with the real quench oil.
But it's been a few years and I don't remember which oil I bought but it works. Keep working at it, you're doing good :D

Don Hanson lll
 
You guys are too kind.......I will have to do a pass around knife for the smth forum guys to show my appreciation!
 
kinda.... he's saying that with a small microstructure in the steel it reacts quicker to form pearlite...

"So the more grains you have, the more of these points will be available, thus the easier it is for pearlite to form. This is what moves the pearlite nose to the left, and requires us to cool things all the faster. With something like 1095 it could even make it impossible to achieve maximum hardness.

This is why one of the standard industry answers to incomplete hardening is to increase the austenization temperature a bit. A slightly larger grain size will retard pearlite formation and increase hardness."

so increase the austenization temp a little ..... and quicken the quench speed



that is ..... if grain size is your prob in hardening....
- otherwise.... it could be decarb... or a funny batch of steel that was less than homogenous, or less than typical o1 elemental make up

yesh... lotsa variables

Greg
 
Greg Obach said:
This is why one of the standard industry answers to incomplete hardening is to increase the austenization temperature a bit. A slightly larger grain size will retard pearlite formation and increase hardness."

so increase the austenization temp a little ..... and quicken the quench speed
Greg
Click to expand...

So I raise my temperature a little to increase the grain size...then lower the quench temp a little...am I getting this idea right?
 
Get yourself some actual quenching oil. Parks AAA is what you want for oil hardening steels.
 
Each mill that makes the steel will make it to a different chemistry not only within the typical chemistry but O-1 has optional elements that some mills may use . Therefore the heat treating response for steels from each mill may be very different !! So stick to the same source especially for tool steels. K Cashen has mentioned this in regards to L-6 either here or swordforum.
 
Gib - you may have hit the nail on the head. The blades easily skip a dull file and a sharp file dign in with pressure aplied :D

I am a happy boy!!
 
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