80CrV2 and 1084 heat treat with basic setup

[PatF]

My understanding is that 80CrV2 is basically 1084, but obviously with some extra stuff. Apparently the added vanadium helps refine the grain size?

 

If my heat treating is SUPER basic (heat a little past magnetic and quench in canola, temper in the oven) am I likely to see ANY difference between the two? My guess is no. 

 

If I switch to a real quenchant (Parks), how about then?

 

For that matter, am I likely to see a difference with 1075?

Edited January 8 by PatF

[Pieter-Paul Derks]

With such a basic heat treat I think you will not get much improvement over a simple steel.

I use 80crv2 primarily and it really needs a 5 minute soak at a relatively even temperature. 

 

I use a oil drum furnace with a simple burner, so it is not like you need a super expensive electric oven or anything.

When you do get the heat treat right it is a fantastic steel, fine grained but still very tough.

 

Parks 50 is too fast of an quenchant, you would need a slower oil as well, I guess heated canola would work.

[Alan Longmire]

Pieter is right.  The chrome in the 80CrV2 is what requires the short soak, the vanadium prevents grain growth.  If you can control the temperature of your forge with some accuracy, you can do that sort of short soak.  

 

You do, however, need to get yourself a length of steel tubing that will fit in your forge and cap one end closed.  This is a muffle pipe, and if you stick a little charcoal down the to the far end while it's at heat it will remove the oxygen from inside, preventing scale and decarb.  Throw your magnet as far away as you can, it is not telling you anything useful for any alloyed steel (that is, any steel that has anything except iron, carbon, and manganese in it).  When 80CrV2 goes nonmagnetic, it still needs to be around 125-150 degrees hotter before it begins to transform.  Instead of a magnet, watch the shadows.  This is the other reason for the tube, you can see the shadows form and disappear.  It's almost impossible in an open forge.  The shadows appear right as the steel is starting to transform.  When they are all gone and the steel is noticeably brighter all over, the transformation is complete and you can quench.  For things like 80CrV2 that need a little extra time to get the chromium carbides into solution, hold it at the heat for a few minutes.  Do a forum search for decalescence, that's what the shadow thing is called.  

 

Both 80CrV2 and 1084 quench fine in hot canola, Parks 50 won't give you any advantage.  It's for water-hardening steels like 1095, W1 - W2, and low-Mn 1075.    

[PatF]

Thanks all!

 

And thanks for the tip on the muffle pipe. I've heard of, and tried to look for decalescence, but have never been successful in seeing it in my open forge. Does that happen with every steel or just higher alloy steel? My forge setup is non-optimal (wife bought me a two burner square devil forge before either of us knew any better and I love her to pieces for it; so that's what I'm using and figure I'll use it till I burn it up) so maybe I'll just stick to simpler steels and ornamental work.

 

And thanks for the info on Parks 50, I'd heard so much about it that I had it built up in my head without thinking if it really WAS more appropriate for my uses.

Edited January 9 by PatF

[Doug Lester]

Sounds a little backwards but the way I learned to spot decalescence is to heat the steel to yellow (I've never seen cherry red in my forge under any ambient light situation) and check for the recalesence.  The shadow passing over the steel looks the same but it's as the returns to a dark red.  They're both caused by the steel giving up energy to change phases.

 

Doug

Edited January 9 by Doug Lester

[Alan Longmire]

On 1/9/2023 at 2:24 AM, Doug Lester said:

They're both caused by the steel giving up energy to change phases.

 

Nope.  Absorbing on the way up (thus the dark line) giving it up on the way down (bright line).

 

On 1/8/2023 at 11:35 PM, PatF said:

Does that happen with every steel or just higher alloy steel?

 

It works for all water-hardening and almost all oil-hardening steels.  Once the chromium level gets over around 10% decalescence gets iffy.  For things like A2, D2, and all the martensitic stainless steels it can't be relied on, which is just as well since those all require a fairly long soak at critical* to fully redistribute the carbides.

 

But yeah, all the 10XX series, 5160, 52100, and anything that doesn't require a soak longer than a minute or two, it'll work every time.

 

* edited to add: "critical" is different for each alloy, it is NOT when the steel goes nonmagnetic.  It is when the crystal structure changes from body-centered cubic to face-centered cubic, allowing carbon to go into solution.  For 1095, this is around 1425 F, which is 10-15 degrees above non-magnetic. For 5160, this is around 1550 F, 125 degrees past nonmagnetic.  For low-alloy stainless steels like AEB-L, this is around 1925-1950F, about 540 degrees above nonmagnetic, plus you then hold it for ten minutes at that heat to fully dissolve the carbides.  Plus it does the crystalline transformation at around 1650, but isn't ready to harden yet because the carbides don't go into solution until the higher temperature, which is why decalescence doesn't work for stainless and high-alloy steels. And AEB-L is an "easy" stainless... 

Edited January 11 by Alan Longmire
clarifying things

[PatF]

Thanks for the addendum!