Still having trouble with heat treat... anyone in Utah?

M

Mikmerk

Joined
Apr 23, 2016
Messages
15
I have an evenheat kf27 kiln.

I have tried to HT 1075, 1084, 80Crv2, and 5160

Basic Protocol:

I've been soaking at 1500 for 10 min, then quenching in 3 gallons of canola oil heated to 140F.

1075 has reached max hardness 64HRC

5160 has reached max hardness 64HRC

80Crv2 lands consistently at 54HRC

1084 has never been above 40HRC

All my results have been inconsistent but these are the best.

All the Steel varieties reached full hardness when quenched in 8% brine. Then they promptly fractured.

I've tried canola oil, vegetable oil, corn oil, water, brine, interrupted quench. 1475F, 1500F, 1520F, 1550F, 1600F, 1650F before quench. 3min soak, 5 min soak, 8 min soak, 10 min soak.

I've normalized before quenching, and I've tried repeated heat and quench cycles back to back.

I've ground down .060 to see if it was the same HRC through and through (it was).

I've tried letting the steel cool in the oil, in the air, and water quench after oil.

One experiment involved 4 identical 1075 tokens (notched for id purposes). Each was quenched at a successively higher temp. Then one quenched at 1500 hit mid 40's HRC, 1550 was Full hard at 65HRC, 1600 was 61HRC, and the 1650 had some spots at 61 HRC and some at mid 50's.

Is there anyone in Utah near SLC that has successfully treated these steels? If so come to my shop and show me what I'm doing wrong. I'll buy you lunch.

I'm guessing that I'm doing something fundamentally wrong or there is a serious flaw with my setup.
 
It is very likely that the 80CrV and 1084 are fully spheroidized when you get the steel. This means you have to cycle the steel as part of the HT to break down those balls of carbides. Start with a soak of 15 minutes at 1650F, cool to black and repeat at 1500F, then another cycle at 1350F... quench after the last cycle. Now it is ready to do the HT. Most makers do this on all carbon steel they HT.
 
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Stacy E. Apelt - Bladesmith said:
It is very likely that the 80CrV and 1084 are fully spheroidized when you get the steel. This means you have to cycle the steel as part of the HT to break down those balls of carbides. Start with a soak of 15 minutes at 1650F, cool to black and repeat at 1500F, then another cycle at 1350F... quench after the last cycle. Now it is ready to do the HT. Most makers do this on all carbon steel they HT.
Click to expand...

Ok, im sorry, this has blown my mind. Most new knife makers choose 1084 because of its ease of heat tx. Now we may have to Consider cycling to get the most out of it depending on its state. Read a few other post just like this with individuals having trouble with 1084 hardening.

Ok:

To heat treat 1084:
Ramp to 1650, soak for 15 minutes, cool to black
Ramp to 1500, soak for 15 minutes, cool to black
Ramp to 1350, soak for 15 minutes, then?? Qwench in oil? Or cool to black also??

Followed by 1475-1500 roughly 5 minutes then quench in oil to harden.

My main question is what to do after the 1350 soak for 15 minutes, its unclear to me

Thanks!
 
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In for details. Aka Solution.
Please fill us in with particulars.
Thanks Dozier.


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The 1084 and the 80Crv2 that I'm having trouble comes from Aldo. I've read here and there that his steel is spheroidized. This very well may be the issue with my HT. I plan to run a full thermal cycle and quench here soon, then a thorough grinding to remove any decarb before hardness testing.
 
Ja Baudin said:
Ok, im sorry, this has blown my mind. Most new knife makers choose 1084 because of its ease of heat tx. Now we may have to Consider cycling to get the most out of it depending on its state. Read a few other post just like this with individuals having trouble with 1084 hardening.

Ok:

To heat treat 1084:
Ramp to 1650, soak for 15 minutes, cool to black
Ramp to 1500, soak for 15 minutes, cool to black
Ramp to 1350, soak for 15 minutes, then?? Qwench in oil? Or cool to black also??

Followed by 1475-1500 roughly 5 minutes then quench in oil to harden.

My main question is what to do after the 1350 soak for 15 minutes, its unclear to me

Thanks!
Click to expand...

You can oil quench or cool to black. It really isn't much difference. Oil quenching locks in the fine grain as martensite. Cooling to black locks it in as pearlite. In either case, you are going to convert to austenite in the HT and then convert to martensite in the final quench. I think I quench because it is faster, and I am going to put it right back in the forge for the final heat and hardening.
 
Mikmerk said:
The 1084 and the 80Crv2 that I'm having trouble comes from Aldo. I've read here and there that his steel is spheroidized. This very well may be the issue with my HT. I plan to run a full thermal cycle and quench here soon, then a thorough grinding to remove any decarb before hardness testing.
Click to expand...


THIS

I was under the impression that Aldos 1084 came normalized and ready to grind , shape and then heat teat/quench. Much consternation with the last batch that will not hold an edge. Man that is a lot of heat treating.
 
So, using Aldos 1084 and a 2 brick forge, just eyeball the best you can? Kind of hard to hold soak times with a forge, but 1084 is the recommended steel for "backyard heat treatment" I'm at a bit of a loss.
 
I get my Steel from jantz knife supple (not plugging) it comes annealed. I don't have any issues with their 1095 when I quench in 10w-40 motor oil. I water quenched once and it warped so lesson learned there.
 
Living The Dream said:
THIS

I was under the impression that Aldos 1084 came normalized and ready to grind , shape and then heat teat/quench. Much consternation with the last batch that will not hold an edge. Man that is a lot of heat treating.
Click to expand...

I'm about to call everyone I made a blade for out of Aldos steel. I have no complaints, including the blades i use myself that I made. But i can tell,, dang. When I heat tx D2, and s35vn, those blades always feel so much harder than the 1084's. Guess i know why. Who sends out 1084 for HRC testing?
 
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Ive invested over 300 dollars to tailor a ht for s35vn, but Im second guessing myself about 1084 now. I feel stupid.
 
I think I may start a new thread because I use a forge and don't want to derail the OP 's thread. But now I have a whole new range of questions.
 
Guys, It has been quite a journey so far learning about HT. Luckily I have a Hardness tester on loan from a friend so I can measure my results. Don't get me wrong, I love Aldo's steel and will continue to buy from him. I'm just trying to find any patterns I can with the steel I'm using to determine the failure in my system.

I understand the worry though. I have a friend who has been making and selling superb knives for some time and even he admitted to me that my findings were causing him to second guess his methods. Luckily I have one of his knives and found that it tested out just fine.

I received some excellent advice from DevinT, and that is start simple and not mix everyone's methods or info on the web. I have to find out what works with my equipment and go from there.

I admit, it is frustrating. I didn't even know what Spheroidized meant until a few days ago. When i finally figure it out however, I'll have a confidence level in my work that will be supported by a foundation of solid experience.
 
Alpha Knife Supply said:
Not all spheroidized annealed steel requires a non standard heat treatment.

Chuck
Click to expand...

I will comment on that a bit.

Chuck is right, it isn't always an issue.

Much process annealed steel isn't 90-100% spheroidite. Just calling it annealed can be confusing. That is why guys like Aldo and some other suppliers specify the steels they carry which have been fully spheroidized.

With hypo-eutectiod steels and steels at the eutectoid, the issue is pretty small. There is less carbon to be concerned with extra carbides. Also, these steels have a higher austenitization temperature. I personally don't think properly austenitized 1084 would need it.

52100, W2, and 1095 may gain a good bit from thermal cycling if they came at 90+% spheroidite. Without a sufficiently long soak, the lower austenitization temperatures used in the HT of these hyper-eutectiod steels can be low enough to not release the tied up carbon (resulting in soft blades). Most folks who are having problems are forge HTing their blades, and thus not getting a full soak of 10-20 minutes. In most cases where an oven HT did not get the desired results, a longer soak and assuring that the blade is truly at the desired temperature will solve the problem.

As has been pointed out by Bill Burke in another thread, one long soak ( or even better three long soaks with a cool to black between them) at 1550F will also break down spheroidite. This is followed by a normal HT.
 
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