80crv2

[Geoff Keyes]

Does anyone have the HT for this nailed down? I've been treating it like 1084 with good results. I've heard that an 1800F soak pre-HT helps dissolve carbides.

 

Geoff

[Geoff Keyes]

OK, I don't know where the 1800F came from, stuck in my head from somewhere. I found this on a UK site.

 

 

 

I use 80CrV2 a fair bit, tough old steel and does need good temperature control to get best out of it

If forging, then don't forge below 900C or about 1100C. Normalise at 860C to redissolve Chromium, then any other normalisations or anealings that you like doing. Harden 830C (off top of my head) with a soak of at least 5 mins and temper at between 200 and 250 depending on hardness desired, mostly I find 230 good for general purpose knives

 

Geoff

Edited April 23, 2016 by Geoff Keyes

[Gabriel James]

I definitely wouldnt say "nailed down" but Ive been heat treating it like 1084 maybe only a tad hotter, only difference is during normalization. First normalization cycle u take it 100-200 degrees hotter than normal to put these alloys into solution in the steel, 2nd cycle is 50+, and last one is sub critical to even the grain out before HT.

A lot of the stuff i read had people quenching in water and stuff, which i ignored and i was pleased with my results.

 

 

Since i have a fair amount of this left id like to see any other options that others might have better success than mine since i only have done 2 blades in this so far.

[JJ Simon]

As I understand it there is a wide window of results you can get depending on the way you cycle the steel.
So it can vary in toughness and hardness.
Aldo might have the info and I think Kevin the professor has a good handle on the whats and hows of it.
The one thing I noticed after heat treat is that it has a deep decarb and then is hard as Chinese arithmetic!!!

[Wes Detrick]

In a follow up to another post, I told them that I would tell how I heat treat 80CrV2. I broke a blade after this heat treat and had great grain on it, and it was tough and hard as hell, so here is how I heat treat it.

 

I use my propane forge, a baffle pipe, and a thermocouple so depending on what you use, your results may vary.

 

I do the standard three cycle normalization followed by a quench into Parks 50. I do this at night so I can watch for recalescence.

 

The knife goes into the forge cold, the forge is fired up, and then gets heated to 1600 F slowly. I think this first heat cycle takes maybe 30 minutes to get to temp, so real slow. I leave it at 1600 F for a few minutes(2 or 3 maybe), farting with the gas if I have to to keep it there. Take it out and cool in still air. The forge is turned off and while the knife cools, so does the forge.

I let the forge drop to 1325 F or so, then the knife goes back in. The forge does not get fired up again until 1200 F though.

 

Once at 1200 F, the forge gets fired back up again, and the knife is brought up to 1550 F slowly. The second heat is faster than the first, but it still takes 10 minutes or so. By this point, I have the gas turned way down so that the heat builds slowly. Once at 1550 F, it stays in for a few minutes again, and then back out to cool. Forge is turned off again. Knife goes back in the forge at 1325 F, and the forge is fired back up again at 1200 F.

 

Once at 1200, the forge gets fired back up again, and the knife is brought up to 1500 F slowly. The third heat takes about as long as the second, around 10 minutes or so. The gas turned way down so that the heat builds slowly and if possible, I turn it down even more. I typically have the torches right above the point where they start to sputter. Once at 1500 F, it stays in for a few minutes again, and then back out to cool. Forge is turned off again. Knife goes back in the forge at 1325 F, and the forge is fired back up again at 1200 F.

 

Once at 1200, the forge gets fired back up again, and the knife is brought up to 1500 F slowly. The last heat takes about as long as the second third, around 10 minutes or so. Torches are still really low. Once at 1500, it stays in for a few minutes again, and then quickly goes nose down into the Parks 50 until warm enough to hold. I know Parks is a bit fast for 80CrV2, but I haven't had an issue yet and it has produced good results. Once out, file test, and like JJ said, it has some thick decarb on it. And hard as Chinese Arithmetic like he said

 

Into the over for temper between 400 and 425. I use an oven thermometer to make sure the temp is right. This is the grain I get:

 

 

It comes out hard as wood pecker lips. I locked this blade into my post vise and it took 4 solid two handed hits with my 4 lbs sledge to break that knife. There was almost no deformation of the blade, other than a very slight bend. I was impressed.

[JJ Simon]

Thanks for the info.
When I've worked with it, I have done a forging heat cycle, A cycle above 1600, a cycle in the solution zone between 1450-1550 and a sub critical cycle.
I have read that the sub critical cycle just makes it tough as hell.
It so far is an amazing steel.
My only complaint is the deep decarb.
But it is stunningly hard.
Basically hard like 1084 but with the other alloys that make it like 5160. Like a spring.
It would be great to see what your hardness is at after temper.
I'm going to be its over 60R.
And that is pretty impressive.

[Wes Detrick]

Thanks for the info.

When I've worked with it, I have done a forging heat cycle, A cycle above 1600, a cycle in the solution zone between 1450-1550 and a sub critical cycle.

I have read that the sub critical cycle just makes it tough as hell.

It so far is an amazing steel.

My only complaint is the deep decarb.

But it is stunningly hard.

Basically hard like 1084 but with the other alloys that make it like 5160. Like a spring.

It would be great to see what your hardness is at after temper.

I'm going to be its over 60R.

And that is pretty impressive.

 

My pleasure JJ. This forum has helped me in more ways than I can count, so if I have the chance to pay back, I am grateful.

 

I do the cycle above 1600; its my last heat. A full heat, and then it gets put on a brick to cool but I have never done any sub-critical cycling but have heard of other people doing it so I wonder about it. I may have to throw that one in the mix to see how it works out. Is there a recommended temp to take it too sub-critical? Is a soak at that temp recommended?

 

You know man, I am not sure what the hardness would work out to be. I think the Parks 50 quench would certainly push it pretty high. I have no way to test in any scientific way but like you I am intensely curious what the HRC was after the temper cycles.

[JJ Simon]

 

My pleasure JJ. This forum has helped me in more ways than I can count, so if I have the chance to pay back, I am grateful.

 

I do the cycle above 1600; its my last heat. A full heat, and then it gets put on a brick to cool but I have never done any sub-critical cycling but have heard of other people doing it so I wonder about it. I may have to throw that one in the mix to see how it works out. Is there a recommended temp to take it too sub-critical? Is a soak at that temp recommended?

 

You know man, I am not sure what the hardness would work out to be. I think the Parks 50 quench would certainly push it pretty high. I have no way to test in any scientific way but like you I am intensely curious what the HRC was after the temper cycles.

I don't know what the sub critical temps should be or the length of soak.

As a suggestion you could see if anyone on here has a hardness tester and do a quick beveled piece and harden it both ways and send them out.

[Jerrod Miller]

Sub-critical tempers are done about 25-50 degrees below the austenitic (A3) line and held for a normal temper time (so about 2 hours for knife geometries). I have access to a Rockwell tester and would be happy to run a chunk if you want (PM me if interested and I'll send you my address).

[Wes Detrick]

Sub-critical tempers are done about 25-50 degrees below the austenitic (A3) line and held for a normal temper time (so about 2 hours for knife geometries). I have access to a Rockwell tester and would be happy to run a chunk if you want (PM me if interested and I'll send you my address).

 

Crap, I have no way to hold anything at any given temperature for that amount of time. I can do a spat of minutes, but in order to do a soak that long, I would have to hover over the gas valve constantly turning it off and on. No thanks.

PM inbound Jerrod, and you have my thanks!

[Jerrod Miller]

Yeah, a sub-critical anneal/temper is great for things that just won't get soft with a normalize cycle in industrial applications, but for the hobbyist they aren't overly practical. That is the major reason I'd say people should stay away from 440C. I should probably mention that a soak at that temp for 10 minutes or so would probably be better than nothing, especially if you could just leave it in the forge to cool down slowly.

 

Also, "funny" story: Same type of thing happened to me last night. Forging out a 1084 "blacksmith knife". I was keeping the blade cool and heating the tang to wrap it around to form the handle and the freaking blade cracked in my hand. Time to heat treat it and test to failure. That will have to wait for next week though, Ren-Faire in Wenatchee this weekend; I help with the joust team (man the list, pick up broken lance shards, help knights with armor, etc.).

[JJ Simon]

I feel both you guys pain.
I ground right over a plunge line, basically making a flat from the ricasso to the tip so I went to do the same on the other side.
Which is fine, except I have knives to finish for blade.
So this thing can sit in the reject pile.

[Wes Detrick]

Yeah, a sub-critical anneal/temper is great for things that just won't get soft with a normalize cycle in industrial applications, but for the hobbyist they aren't overly practical. That is the major reason I'd say people should stay away from 440C. I should probably mention that a soak at that temp for 10 minutes or so would probably be better than nothing, especially if you could just leave it in the forge to cool down slowly.

 

Also, "funny" story: Same type of thing happened to me last night. Forging out a 1084 "blacksmith knife". I was keeping the blade cool and heating the tang to wrap it around to form the handle and the freaking blade cracked in my hand. Time to heat treat it and test to failure. That will have to wait for next week though, Ren-Faire in Wenatchee this weekend; I help with the joust team (man the list, pick up broken lance shards, help knights with armor, etc.).

 

I feel both you guys pain.

I ground right over a plunge line, basically making a flat from the ricasso to the tip so I went to do the same on the other side.

Which is fine, except I have knives to finish for blade.

So this thing can sit in the reject pile.

 

The blacksmiths gods demanded their sacrifices again. Must be something for the air. Sorry about the loses

JJ, I did almost something similar with the knife above. I was trying to cut the plunge out a little more with a belt, and it rolled right over the edge too much and just ruined it.

Edited April 30, 2016 by Wes Detrick

[JJ Simon]

I understand. I am discovering that it is better for me to go back and put my file guard back on when doing this and even if its a mm closer to the shoulders and I basically make a new plunge line, its still better than rolling them over.

[Kevin Colwell]

I just saw this. Family health issues last week, but everyone is ok now.

 

I cycle through 3 normalizations, 1600, 1500, 1420. Then, I heat to 1475 and soak for 10. Probably don't need it, but the soak makes me feel better (chrome and vanadium).

 

I temper 3x. 385, 400, 410

 

This formula works good for me. If (when) I make little puukkos, I change the tempering. I temper about 15F cooler at each cycle. John Doyle told me that he gets great results with tempering at 385F.

[Wes Detrick]

Jerrod was able to get my knife tested for hardness and this is what he found:

 

Spine = 57 HRC

Center near break = 57 HRC

Edge = 53 HRC (this reading is questionable due to the thinness of the part near the edge)

Ricasso = 58 HRC

He made mention that the edge test is in doubt because of how thin it is and how much it flexes. I would image that most people go with a test on the ricasso where the testing mark could be covered. Post heat treat grinding was done such that the blade never heated up to a point where I couldnt handle with bare hands, so I am going to say that the edge is about 57/58 HRC like the rest. If Jerrod wants to weigh in and give the gory details, I will leave that up to the expert.

What this does tell me though, is that I am going to take my temper down to between 375 - 400 to keep a little more hardness in it. I had tempered this blade twice for an hour each at 425. Other than that, I am fairly satisfied with my heat treat of the steel. Just need to dial that temper back a bit and we should be golden.

[Jerrod Miller]

I think that covers it pretty well. The test near the edge was pretty close and thus in fairly thin metal, and any flex that may occur would certainly explain the lower reading. I can snap a picture of the blade to show where the hardness tests were done if there is any interest (and if Wes is cool with it, it is his blade after all).

[Wes Detrick]

By all means Jerrod, please take pictures if you would like. Do whatever you like with the blade now. A teaching aid for what not to do?

Edited May 26, 2016 by Wes Detrick

[Austin_Lyles]

Picked up a bunch of this stuff last night. Excited to see how it performs. Seems everyone has great things to say about it so we'll see what all the buzz is about.

Edited May 26, 2016 by Austin_Lyles

[Jerrod Miller]

Here it is. You can see I got quite close to the edge for that test, while not sharp, the blade did get pretty thin near the edge. If I get a chance to run it on a Vickers I'll see what it really is, but I'd bet that it is in the 57-58 HRC range like the rest of the blade.

[Wes Detrick]

Ugh, you can see where I rolled over the plunge with the belt. Thanks for posting that Jerrod. I hope my failures help other people.

[Jerrod Miller]

If it were me, I'd have just gone with it. Roll both sides a bit, or just move it back on both sides, or even get rid of the plunge altogether. Remember, if it is symmetrical it is a deliberate pattern.

 

Honestly, I didn't even look at the plunge until well after I did the hardness test.

[Joël Mercier]

Found this data on an European website. Quench temp is higher. 

Heat treatment: Hardening temperature 840-880°C (1545 - 1615°F), holding time 5-10 min. Quenching in oil.

Tempering 2 hours

150 celcius..........63hrc

200 celcius .........60hrc

250 celcius..........57hrc

http://brisa.fi/knife-steel/80-crv2.html

Edited October 31, 2017 by Joël Mercier

[Wes Detrick]

I would say that those Austenizing temps are little high. The bottom end temp is close to what I do at 1525 but that top end temp is a bit high. I would start to worry about grain growth.  Maybe the Vanadium helps counteract that, but still, I would use the bottom end temp.

The temper temps are about spot on for what Jerrod found with my test knife, what the Prof is reporting above.  375 F should give you right about 61/62 RC.  Go a little higher for a big blade.

[Vern Wimmer]

43 minutes ago, Wes Detrick said:

I would say that those Austenizing temps are little high. The bottom end temp is close to what I do at 1525 but that top end temp is a bit high. I would start to worry about grain growth.  Maybe the Vanadium helps counteract that, but still, I would use the bottom end temp.

The temper temps are about spot on for what Jerrod found with my test knife, what the Prof is reporting above.  375 F should give you right about 61/62 RC.  Go a little higher for a big blade.

Does a small, sub 4", blade tempered at 375F, say, flat ground with a micro bevel, pass the brass rod test ?