Re heat treat Magnacut

[Scaniaman]

I have a few blanks that warped so bad I will have to do the HT over again. Kan someone give me the steps, time, temps for this? I'd be really greatful. Thanks!

 

[Taz]

Carbide hammer won't work? I had a warp as deep at 3/16" on some 24" OAL pieces of 1/16" Magnacut. Carbide hammer straightened them all out!

I use 1300 for 2 hours, slow cool as a stress relieving step. Then it's 2150 for 10 minutes in foil pouch, plate quench for around 2 minutes, into a bucket of ice water, wipe dry and then into liquid nitrogen. Temper to desired rockwell; I usually do my kitchen oven at 335, which is really around 345ish and gives me 64 HRC.

 

[Scaniaman]

I was in a hurry and dropped som blanks out of cryo onto a surface that the sun had heated a bit...very clever. They warped like crazy. Half circles basically...well almost.

So no full anneal before repeating the aust, cryo and temper?

 

[Taz]

Oh wow! I let them hang out of cryo so they warm up evenly.

I think most people just re heat treat and don't anneal. To anneal it, you bring it to 1650 and then cool 25° per hour until it's down to 1100° and then shut off the furnace and let it cool. It's 22 hours for the annealing process, which is a long time to have a oven going!

 

[Scaniaman]

Ok. Yeah I also let theem hang but was stressed AF and had a bunch of blades to handle and my mind slipped.

 

[Scaniaman]

So I did the heat treatment over. Came out just as warped.
So I think I'll go full anneal. Straighten. Then new heat treat.
Should I have any particular expectations on a third HT after full anneal, in terms of properties and performance?

 

[DevinT]

How thick is the material?

Hoss

 

[Scaniaman]

How thick is the material?

Hoss

The blanks are at 3 and 3.7 mm appr.

 

[DevinT]

The blanks are at 3 and 3.7 mm appr.

If you anneal the material, make sure you foil wrap it several times, steels alloyed with molybdenum are prone to heavy decarb.

Hoss

 

[fitzo]

If you anneal the material, make sure you foil wrap it several times, steels alloyed with molybdenum are prone to heavy decarb.

Hoss

That’s an awesome little nugget of info presented in a great way to tuck away in the memory files, D DevinT ! Thank you, sir!

 

[Scaniaman]

If you anneal the material, make sure you foil wrap it several times, steels alloyed with molybdenum are prone to heavy decarb.

Hoss

Ah, decarb. I have that too. This heat treat was a lot of fun see. Not only did I warp blades like a pro. I also used a new foil that the manufacturer claimed good to 1200 C. Well turns out is was magical foil, it had disapeared once I opened the furnace to get the blades out.
I give you decarb and warp:

https://imgur.com/a/zCMa1sA

 

[Taz]

Oh, Carbide tipped hammer will take that warp out quickly!!

 

[DevinT]

Ah, decarb. I have that too. This heat treat was a lot of fun see. Not only did I warp blades like a pro. I also used a new foil that the manufacturer claimed good to 1200 C. Well turns out is was magical foil, it had disapeared once I opened the furnace to get the blades out.
I give you decarb and warp:

https://imgur.com/a/zCMa1sA

Dang it

Hoss

 

[HSC ///]

Oh, Carbide tipped hammer will take that warp out quickly!!

agreed

 

[Nastasiia Coval]

I have a few blanks that warped so bad I will have to do the HT over again. Kan someone give me the steps, time, temps for this? I'd be really greatful. Thanks!

Oh no, sorry to hear about the warping! I’ve had that happen too — someone recommended full annealing, straightening, and then doing a fresh HT. The temp/time depends on the steel — for example, AEB-L is often heat treated around 1050°C for 10 minutes. You’ve got this!