Metal testing question

J

johnggrg

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Jan 17, 2010
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Ok have a problem. Started making my first knife from some D2 tool steal a friend gave me. I am in the process of removing stock on the blade. My friend that gave me the steel came over and seen the knife and said looks good. I said I will have to send it out to be Heat treated but they have to know for sure what kind of steel it is. So I asked him again about it and he said he is almost positive it is D2. I'm like I thought you said for sure and he said he got it from the rack where all the D2 steel was so he is almost positive. So my problem is do I send it in for HT assuming it is D2 and go from there or test it. I called a place that was local and they said they would have to know what type of steel it is to test it? I said if I knew I wouldn't need it tested. He also said if it was D2 they couldn't test it. If they could it would cost $65.00. So not sure what to do on this. I can't afford to have it tested at this time and I am almost done with the forming of the knife. Not sure if I should just throw in the towel on this or what. Any thought on what I could do? Thank you. john
 
Can he tell you what other steel it could possibly be. Knowing that could help. Also if he has a piece of known D2 take it and grind it and compare it to grinding some of the scrap from the piece you made yours from. Sparks should be very similar if the same steel. If it could be a non air hardening steel try heating a piece to quite a ways past non magnetic and then waving it around in the air till it is cool then check it with a file. D2 would get very hard. Something like 52100, 5160, 1095-1070 would not.
 
Years ago I had a chunk of steel I was told was D2 (i.e. I bought it as D2) and I tried to test harden a piece with the "heat -n- wave" technique. It didn't work. I was convinced that I'd been rooked.

A bit later I learned that D2 requires soak time (20 minutes or more) in order to harden...

Dave
 
It always pays to know exactly what steel you have, and the HT specs on it, even if you send it out. That way you can ask questions and make sure your heat treater knows what he is doing.
 
Abrasive said:
Years ago I had a chunk of steel I was told was D2 (i.e. I bought it as D2) and I tried to test harden a piece with the "heat -n- wave" technique. It didn't work. I was convinced that I'd been rooked.

A bit later I learned that D2 requires soak time (20 minutes or more) in order to harden...

Dave
Click to expand...

So would this be a good test? But let it soak for 20 minutes? If this would be a good test please let me know. I have a friend that could heat it(an extra piece) up with a torch to test it. I had heard D2 was an air cooled metal. This seems to be my only way of testing it. If it works then i can send it in as D2.
Any thoughts? John
 
I'd spark test it and rust test it against a known piece of D2 in the same condition (spheroidized annealed, not hard). If it tests the same then harden test a piece. If it looks like a duck, walks like a duck and quacks like a duck - it is most likely some kind of a water fowl.
 
At the moment I don't have a known piece of D2. I know this steel is really hard. And if it gets any water on it and it will start to rust pretty quick. But I do have a scrap piece that I could get heated up and do that type of test now. So would the heat test work? Would I air cool or quench it for 20 minutes? Thank you for trying to help me out with this. John
 
johnggrg said:
At the moment I don't have a known piece of D2. I know this steel is really hard. And if it gets any water on it and it will start to rust pretty quick. But I do have a scrap piece that I could get heated up and do that type of test now. So would the heat test work? Would I air cool or quench it for 20 minutes? Thank you for trying to help me out with this. John
Click to expand...

Anyone? John
 
Well, I have always soaked my D2 for 30 minutes at 1850 then quenched between 2 pieces of aluminum. But, if it got near that temp and was air cooled it would get hard. Not as hard as possible. Simple steels would not. D2 doesn't spark much and simpler steels do. grind it first.

But, annealed D2 is not very hard and will not start to rust very quick with just getting some water on it.
 
What Nathan said.

Yes, D2 is air-cooled.

You will have a hell of a time holding temperature, without over- or under-heating for 20 minutes with a torch. I am sure there is some guy out there who's a torch savant and could do it in his sleep but it ain't me.

Annealed D2 will rust more readily than hardened D2, but neither of them rust quickly with just a little water. I'm a bit suspicious there.

The unfortunate truth is that you have to pay for results when making blades - or anything, really. If you want to use mystery steel, you are either going to have to test a bunch of pieces and see how they harden and wear, or have the steel tested. I am all for recycling materials but have just about given up on that for anything critical. It's so much better all around to know what steel you are working with before you put hours and hours into it.

That said, don't throw in the towel. Here is what I'd do. Probably. ;) If you can test a couple of pieces and get them to air harden, have it HT'd as D2. If it isn't D2, it won't be optimal but it won't be the end of the world. Have them leave it a bit on the hard side - you can always temper it back a bit.

Dave
 
Thank you for the replies. What I meant to say about the rust was it showing signs of rust. I guess I'll see if I can test a scrap piece and go from there. As for hardness. This steel already seems hard. But I will finish it anyway. As it being my first and I can still learn from it. John
 
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