heat treat confusion

J

Jax knives

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May 25, 2020
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Beginner knife hobbyist. First time heat treat apparently wasn't a success. Not sure if I have a heat treat or a tempering problem.

I did (5) .125 1180 carbon steel blades at 1475* no soak and canola quench with two 2 hour temper cycles at 375* . That netted the smallest blade hardness tested at 56 and the rest in the mid 40's. I also did (3) 1095 blades at 1500* 5 min soak and canola quench and two 2 hour temper cycles at 375* and that netted a hardness test in the mid 40's also.

Everyone of theses passed the file/skate test and were obviously nowhere near target hardness
 
What furnace and what quench oil are you using?

Hoss
*oops, I see you’re using canola oil.
 
Jax knives said:
Beginner knife hobbyist. First time heat treat apparently wasn't a success. Not sure if I have a heat treat or a tempering problem.

I did (5) .125 1180 carbon steel blades at 1475* no soak and canola quench with two 2 hour temper cycles at 375* . That netted the smallest blade hardness tested at 56 and the rest in the mid 40's. I also did (3) 1095 blades at 1500* 5 min soak and canola quench and two 2 hour temper cycles at 375* and that netted a hardness test in the mid 40's also.

Everyone of theses passed the file/skate test and were obviously nowhere near target hardness
Click to expand...

Are you sure you ground past the decarb before you tested?

The temps are backward. I use 1475 for 1084, but 1080 should use 1500. 1095 shouldn’t be heat treated above 1475. You are ok going down to 1450 even. You will get retained austenite with higher temps on 1095.
 
JT knives

Could my improper quench oil be the
main source of my problem. Is it possible my temp was acheived but the improper quench kept it from hardening?
 
Forged or stock removal? If forged, I'd suspect lack of thermal cycling/normalizing. If stock removal, you have had some of Aldo's that was very spheroid annealed.
 
Jax knives said:
JT knives

Could my improper quench oil be the
main source of my problem. Is it possible my temp was acheived but the improper quench kept it from hardening?
Click to expand...

It’s possible but if your temps are what thy say and the hardness tests are accurate then you have fell victim of NJSB. I have gotten tons of blades from customers out of these alloys from NJSB and let’s just say I’m surprised when the steel actually hardens. I dont know what is going on with there simple carbon steels but I see this problem a lot. I have tried all their recommended thermal cycling and even going above and beyond industry standard to try and get it to harden. But the most I get is weird blotchy hard and soft areas.

I would contact them and tell them you want your steel replaced. You can grind the flats and I would lay money that after an etch thy look like this.

Photo%20Dec%2031%2C%209%2007%2041%20PM.jpg


Photo%20Nov%2006%2C%202%2044%2049%20PM.jpg
 
Stacy E. Apelt - Bladesmith said:
How did you determine the hardness?
Click to expand...
I do automated electrical control work for a machining/fabrication company and the shop sup hardness tested them for me on the C scale. Carbon removed and each tested by the first scale hole. The one that was 56 you can barley even see the indent all the ones in the 40's left a divit like you center punched them.
 
JTknives said:
It’s possible but if your temps are what thy say and the hardness tests are accurate then you have fell victim of NJSB. I have gotten tons of blades from customers out of these alloys from NJSB and let’s just say I’m surprised when the steel actually hardens. I dont know what is going on with there simple carbon steels but I see this problem a lot. I have tried all their recommended thermal cycling and even going above and beyond industry standard to try and get it to harden. But the most I get is weird blotchy hard and soft areas.

I would contact them and tell them you want your steel replaced. You can grind the flats and I would lay money that after an etch thy look like this.

Photo%20Dec%2031%2C%209%2007%2041%20PM.jpg


Photo%20Nov%2006%2C%202%2044%2049%20PM.jpg
Click to expand...
JT Knives
I actually posted a earlier thread with what I thought was a decarb problem. I actually ground away my logo on the 1095 blades trying to get rid of the deficiency in the steel. The area"s were like pitted blushed areas almost like blistering.The 1080 blades did not experience that same problem but deffinatley have some discolored blotchy spots on several of the blades.blades.I had come to the conclusion my canola oil quench was the problem or maybe I had over heated them.But the one edc blade that faired 56 deff had an even darker decarb look than all the others.
( I need to figure out how to post pics)
 
Don’t get me wrong I’m not saying that all their steel is junk. I actually buy steel from them but I would never buy 1080-1095 & W2 from them, It’s just not worth the risk. Even if thy where giving it away for free I personally would pass on it. Maybe in Damascus it could get mixed around and be fine but in a mono blade no thanks. Until I can see some ownership or explanations to this issue I’m steering clear. Especially when there are other places with great steel why take the chance. But other then that I have loved their other steel and it’s usually shipped promptly.
 
You said it skated a file, so did those blades I showed. But look at it and the very edge hardened but where we abd I think you test is right behind the first pin hole. It’s soft down the center of the blades. That’s how the steel will skate a file and still test soft.
 
JT

At this point for the knives that will clean up do I attempt to harden them again with more suitable quench oil or do I scrap them all. Pretty disappointing for the 6 that I have heat treated but I have another 7 from the same steel that are shaped/beveled ready for HT
 
Jax knives said:
JT

At this point for the knives that will clean up do I attempt to harden them again with more suitable quench oil or do I scrap them all. Pretty disappointing for the 6 that I have heat treated but I have another 7 from the same steel that are shaped/beveled ready for HT
Click to expand...
Getting some parks 50 will be a good choice no matter what especially if your planning on sticking to steels like 1084, 1095, w2, 8670, 80crv2. Try taking one of the blades and do a high temp cycle by bringing it up to 1800 for just a minute or two then do 3 thermal cycles at lowers temps 1650, 1550, 1450 for example. That may grow the grain to the point it can be refined and hardened properly and may also help evenly distribute everything in the steel. I think when this issue came up before with Njsb’s 1084/1095 the people having issues were only doing stock removal and I believe there were some people forging it that had no issues and I’d be willing to bet it’s something to do with the forging temps.
 
Joshua Fisher

I took you're advise, figured I had nothing to lose at this point but time. Took one blade to 1800 held 2 min and cooled. Repeated with 3 cycles at 1650, 1550 1450.

Re Heatreat at 1500 and quenched in canola oil( no parks yet) and the blade does not pass the file test it is softer now than before so I see no point in hardness testing the blade .

The frustration is starting to sit in. Guys on here have more success with a torch and a magnet than I'm having with an oven.
 
Jax knives said:
Joshua Fisher

I took you're advise, figured I had nothing to lose at this point but time. Took one blade to 1800 held 2 min and cooled. Repeated with 3 cycles at 1650, 1550 1450.

Re Heatreat at 1500 and quenched in canola oil( no parks yet) and the blade does not pass the file test it is softer now than before so I see no point in hardness testing the blade .

The frustration is starting to sit in. Guys on here have more success with a torch and a magnet than I'm having with an oven.
Click to expand...
Your going to have some decarb, how far were you able to file in? Take the blade to your grinder and grind it down a bit then test again or keep filing on it to see if it’s completely soft or if you hit hardened steel after 4-6 passes with the file.
 
Also if you are quenching 1095 in canola you need to make sure the canola is around 120 degrees Fahrenheit so it cools the blade quick enough to get a hardened blade.
 
I have tried high temps, nothing worked for me. The thing that gets me is this steel is touted as the end all be all steel for new knife makers. And all their steel does is make new guys question what thy are doing wrong. I would normally side with the steel and say yeah double check you temps, oil, soak exc. but, I have had this happen to quite a few of my customers Knives and so I know it’s not a process issue. If it has to be forged first then thy need to say something to let people know.

Do you still have your order number. If you can get me your/that info I will contact Their steel quality control guy and ask him what’s up.
 
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