1095

D

dominion22

Joined
Dec 24, 2015
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Hello everyone, new to forum.limited knife making experience. Just purchased an Evenheat kiln and tried my first knife with disappointing results. Using 1095 steel and after researching the process gave it a go. Brought heat up to 1450 F and soaked for 10 mins. ( blade is 1/8" ) and quenched in warm canola oil. Never got hard. Tried more heat, soaking longer and even quenching in warm brine, nothing is working. Last soaking there was a lot of scale and now I'm worried I baked all the carbon out of it. Any advise would be greatly appreciated.
 
Welcome to the forum. Let's assume your kiln is giving you accurate readings, first of all. Second, by FAR the culprit in circumstances such as yours is decarb layer. Not to be confused with scale. Scale is the carbon that has leeched out, and there is a layer of decarb that must be sanded thru before hard steel is reached. Try removing a few thousandths and see if there is hard steel underneath. The decarb layer will be fairly deep, because it sounds like you've run the same knife thru a few hardening cycles. You tried quenching it in brine and it did not get hard? I bet it did, but sand/file thru the decarb layer that is present. As an aside....1095 will get hard at 1450, but should be at 1475 with a 10 minute soak. 130F canola should do decently well with 1/8" 1095. Not the best, but serviceable.
 
The black later came off in the quench, was down to bare metal on spine and steel was soft enough to file
 
That "bare metal" is decarburized steel. Sand/grind off a few thousandths of an inch and all of a sudden sparks will fly and you will be at hard steel.
 
Have you tested your kiln for accuracy? Mine is about 5 degrees off so I have to adjust for that. An important part of learning to heat treat, is learning how your equipment works.

Eta- if your kiln is reading hotter than it actually is, then your aust temp would be VERY low for 1095.
 
Put a few chunks of rock salt on a piece of steel and put it in your kiln. The salt will melt at 1475. It could be a few degrees off due to altitude and impurities in the salt but it will be close enough to properly H/T 1095.
 
1450 will work, but only if the steel has been normalized, thermal cycled, and set up for that type of heat treat. It's a good temp if you are going for a hamon. I'm too lazy to type it out again, and there was a thread on this exact same issue last week. You can look for that thread for the details. I use the same prep as I do for 52100 and W2, for the normalizing and thermal cycling. I use 1460f for austentizing W2 and 1095, and 1475 for 52100. You can fine tune 1095 a bit more with the recipe that Stuart lists, but the difference will be quite minimal, and it takes up another program in the kiln. If you do a lot of 1095, set the kiln up with Stuart's program.
 
I was under the impression that normalizing is only done if the metal has been forged . Does it still need to be done with flat bar that hasn't been worked?
 
i used to be under the same impression. i was told the steel was forged at the factory and annealed when it was made, but not normalized. so, its actually "forged " when you get it.
 
you can also double check your temp with a magnet, as well as salt. a magnet will not stick or attract to steel at all when it is at critical temp. if you feel the slightest pulling of the magnet toward the steel when its red hot, it isn't hot enough. happy holidays.
 
Thanks for the info, first ( of many, I'm sure) learning for me. A couple strokes with a file and steel is hard, in the oven now tempering
 
Many of the steels we use come in a spheroidized state, which makes them easy to grind and machine. If coarse spheroidized, you need to use heat to break up the carbides and get everything into solution. I do it to all my carbon steels now except the 15n20 from Aldo. It just doesn't need it. Normalizing and thermal cycling puts your steel in an optimum condition for heat treat, and I haven't had a blade fail to harden properly since I started doing this. Aldo's 1084 (1/4" stock) and 52100 are notorious for needing thermal cycling. I haven't tried his 1095 without cycling, so I can't comment on how needed it is, but if you do cycle, you know the condition of the steel for sure.
 
dominion22 said:
When plate quenching , should plates be room temp or cold?
Click to expand...

Plate quenching is for stainless steels, and a few other very slow quench rate steels.

1095 is a shallow hardening hyper-eutectoid steel. It needs a very fast quenchant. Parks #50, water/brine are the usual ones used. Water/brine have issues with cracking the blade if you are not experienced ( and even then about 25% may crack). Canola oil will work on thinner knives in 1095. Above 1/8" thick, you will need the faster quenchant.

Just to be clear, if you plate quenched a 1095 blade it would not harden.
 
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