HELP! I can't get 1084 hard

I just had a similar thing happen to me with 1095 . Very frustrating. Talked it over with a few members and decided it was not 1095. Accidents happen ... steel gets mixed up all the time . I use a lot of different steels but I away mark everything. But I took this supposed 1095 from a 48 inch bar color tagged and labeled . I am not going to waste my time trying to figure out what the heck it is. I will find a use for it.

I would just get rid of that steel and make a new order. That way you can get to the bottom of this. Good luck
 
Maybe I have some from the same batch. It's 1/4" and with a 1485 soak for 5 minutes, quenched in brine, it came out at rc45. I was going to redo it just to be sure, but everything else I've done in the past few months has come out in the mid 60s, varying with the steel type.
 
Granted it doesn't happen often, but steel types can get mixed up (somehow). I haven't gotten a *wrong* bar of steel yet, but I remember a bar of O1 that I don't think had consistent alloy chemistry. The first blade from it hardened well enough following the recommended O1 treatment. There were 3 others from the same bar - one went through about 4 attempts, and not even a 10 minute soak at 1700 F with hot water did anything. The other two did not harden in fast oils, but got right around 60 RC if treated like W1/2 and quenched in brine.
 
Was yours 1084 or the 1095 that I was describing ?


Willie71 said:
Maybe I have some from the same batch. It's 1/4" and with a 1485 soak for 5 minutes, quenched in brine, it came out at rc45. I was going to redo it just to be sure, but everything else I've done in the past few months has come out in the mid 60s, varying with the steel type.
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I just placed a order with Aldo for some new stock. We will see if it was me or the steel. One positive in all of this, I have learned a lot more about heat treating.:)
 
Theiskell said:
I just placed a order with Aldo for some new stock. We will see if it was me or the steel. One positive in all of this, I have learned a lot more about heat treating.:)
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Was it Aldo steel that you were having problems with? Or from somewhere else?
 
Sorry just read the OP and saw it was from USAKnifeMaker. Those guys are great there I would call them and explain your issue.
 
I question this just a bit.
When you say "preheated" what exactly do you mean - how much time?
When I preheat for austenizing, I let my oven soak for a full 30 minutes prior to use. It only costs pennies to run the oven that long and it's well worth the time/expense to make things go right.
You want the entire mass of the oven up to your target temp.
When I put a full sized blade in my oven that has soaked at target temp, it only takes 1/2 of your 7 minutes for mine to get to full temp. Actually, about 4 minutes.
Something tells me you're not getting this steel either :
1.) Up to full temp, or
2.) enough soak at full temp.

Theiskell said:
I put the knife in, blade edge up with the oven preheated to 1500. It takes about 7 minutes to become nonmagnetic.
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I let it soak at temp for 20 minutes, sometimes longer if I am doing something. I oversized the element for the size of the oven. It does not have any trouble getting up to temp and holding it. Recovery time is also very quick.

On one of the test pieces I took it up to 1650 and let it soak for 15 minutes it still came out at 42 RC
 
This has got to be a bad batch. I made a file guide out of the same 1084, and soaking at 1490 for 5 min, then quenching in brine resulted in Rc27!!!! :(:(:(
 
Willie71 said:
This has got to be a bad batch. I made a file guide out of the same 1084, and soaking at 1490 for 5 min, then quenching in brine resulted in Rc27!!!! :(:(:(
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I have been playing around with test pieces for the last few days. I don’t understand the results I am getting but I did find something that gave me 64 RC.
The oven set 1675 with 30 minutes of soak at that temperature
Steel soaked from cold for 10 minutes…. looking at color charts online the steel looked to be in the 1650 range. It was orange ???
Immediately quenched in cold 60* water = 64RC
I repeated this same test only quenching in canola oil and got 42RC again. I also tried heating the steel to 1550 and quench in water this gave a 52 RC. Could this be different steel that has to quench in water? Remember I am a virgin at heat treating so go easy on me
 
I can think of 2 possibilities. Your oven/temperature is off or your steel might be a much higher carbon than 1084 (hypereutectoid). Try heating a piece to 1500 F, pulling it out and checking to see if it is non magnetic. If it is still magnetic test at increasing 50F intervals. Heat your test piece to 1675 F and quench in canola - test the hardness, do the same with a brine quench.
 
Bo T said:
I can think of 2 possibilities. Your oven/temperature is off or your steel might be a much higher carbon than 1084 (hypereutectoid). Try heating a piece to 1500 F, pulling it out and checking to see if it is non magnetic. If it is still magnetic test at increasing 50F intervals. Heat your test piece to 1675 F and quench in canola - test the hardness, do the same with a brine quench.
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Yes at 1500 it's non magnetic. I did heat to 1675 and quench in canola and got 42 RC. i haven't tried a brine quench yet
 
If you "calibrated" your oven with an IR gun, that is your first mistake. They are not accurate at those temps, and no good for measuring the air temp in a cavity. If you were getting nonmagnetic at that supposed 1500, that tells me you are off by at least 86 degrees, as the curie point of steel is 1414f (look it up if you don't believe me) Make a test coupon of a fresh piece and preheat your oven to what you think is 1700 for a half hour. Place that test coupon in your oven for 10-15 minutes (no peeking) and quench it immediately. No carrying it across the shop, no dawdling, straight into your brine or whatever in less than a second Leave it in your quenchant until it is at room temperature, then sand it down to clean metal, no scale, then test it. Once you have tested it, put an end in a vise, put on really good eye protection, and break it to see what your grain looks like in the broken section

-Page
 
I know this thread is a month old at this point, but I just ran into the same problem with the same steel.

1/4" thick by 1.5" wide 1084 from USAKM. Tried multiple scrap pieces after I couldn't get the two blades I ground to harden. Hardness was reading between 40-50rc. Used a calibrated Evenheat kiln, 1500F quenched in preheated Parks #50. Heat treated some 1084 from Aldo as well, hardened just fine.

Pretty sure it's a mislabeled or bad batch.
 
I have made a couple more knives out of the same steel. What I found was quench it in water and I get 62-64 straight out of the quench. I tried doing a full grind on one and taking it as thin as I could and it warped on me, but I was able to straighten it out. Using canola the best I could get was 50 rc....I’m new at this so someone with more experience could probably do better, but they were not around at the time :)
 
I just had this same issue with Aldo's 1084. Literally got an email from my heat treater a few minutes ago and he says that half the batch, from 5/32 stock came in where it should. The 3/16 stock is all coming in mostly at 42-43 with two at 52. Doesn't seem to matter what he does, 1500 to parks does nothing, and 1550 to brine still won't make them harder. The the two highest hardness ones also vary pretty bad when testing different areas of the knife. These were done in PID controlled salt baths, by a guy who has been heat treating for 20 years.
 
Just a followup. The supplier did some test coupons, and he got Rc64 out of parks 50. I have found inconsistent results. A few pieces have hardened properly, and others have had soft spots, or didn't harden. The alloying must be inconsistent in this batch.

Warren
 
usa knifemaker is pretty good about replacing orders that are not right. I would let know about your problem and may be they will replace it for you
 
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