Problems hardening W2

T

Tomaz L.

Joined
Jan 20, 2005
Messages
24
Hello everyone! I just got a shipment of W2-equivalent from the steel mill, hot rolled bar stock. I already ground a few blades which I intend to send to a professional heat treating facility later on but out of curiosity I took a few bits of steel and tried to harden them. I used a propane burner to get them to dull red and water quenched immediately. To my surprise I was not able to harden the steel even though I tried a longer soak time and higher temperature. I even tried quenching in brine, no luck.

So this is a bit frustrating... I have a shipment of W2 that I can't seem to harden. I have very little experience with heat treating but W2 is supposed to be pretty easy to harden by water quench. Could there be something wrong with the material? Spark test definitely shows a high carbon content. I suspect the steel came fully spherodized. Does that make any difference?

I would really appreciate any feedback!
 
How did you test hardness ? the hot rolled usually has a layer of decarburized material at the surface .If you just ran a file across it , the file may have bit into the decarb. All tool steel should be sold as annealed otherwise machining will be difficult. Hot rolled is not finished further and ground should have most of the decarb ground off.
 
Hmm might be, but how thick is that layer? Several of the bits I tested were ground so I'm not sure that could be the case. I tried the file test and I also put one of the bits in a vise to see how it would react to bending. The steel bent easily without breaking. :confused:
 
If you are going beyond non-magnetic, quenching into brine and still bending the bar in the as-quenched condition, I would strongly suspect you have soem mislabeled steel. Brine should get W2 harder than than the floor stones of Hades.
 
Doesn't sound like W-2 to me. I quench in oil and it gets very hard and with water it would most likly crack it. I'd send it back to where you got it or at least let them know you want your money back. It should have hardened with what you did.
 
Thanks for your input. Looks like it might be as bad as I thought. The spark test looked pretty good though so I will take a few more samples and quench them before I give up.

One more question though. What is the ideal soak time for W2? I kept the bits (1/4" thick) at red heat for about 5 minutes.
 
I don't know exactly what you did, but to me it sounds more like a temp problem.

Dull red isn't hot enough...the steel would not be austenitized.

I'd recommend you do it in near or complete darkness (as dark as you can without burning your shop down :) )

It will allow you to watch the steel much better.

Taking W2 out of my salt bath at 1450-1550 (depending on what I'm doing with it) it's what I would call a fairly bright orange. Far hotter than red.

Just my $0.02

BTW- what do you mean a W2 equivalent???

-Nick-
 
I'll try that too. As I said, I'm pretty new to heat treating. I did observe the color in semi-darkness though and I did increase the temperature all the way up to very bright orange in the end. The propane burner was not ideal so it's completely possible that the problem is on my end but the whole thing still doesn't seem right.

I say W2-equivalent because I live in Europe and the steel I got is called 1.2833 over here. For all purposes it is identical to W2.
 
You must log in or register to reply here.
Back
Top