To heat treat or not to heat treat

[engineer23]

I am doing a tool wear study using tools fabricated from h13. I'm considering using them without heat treatment in the hopes that I will be able to observe more wear. Is this a good idea or are there adverse consequences to using tools of this material which are not heat treated?

I'm using these tools in FSW (Friction Stir Welding). If you are not familiar with the process, here's a link to the wiki which gives a good overview:
http://en.wikipedia.org/wiki/Friction_stir_welding

 

[FredGarvin]

I have never worked with FSW and I don't play one on TV either.

I would think that the tool temperature is going to be high enough that any kind of heat treat you have will be eventually lost. Have you done any post work inspections on the microstructure of a used tool?

 

[engineer23]

I tend to agree with you on that point. I think I'm going to just use them as-is without heat treatment. We've used tools made of softer steels before with no problem, so I imagine that untreated h13 would be comparable to those in properties. I'm just looking for wear and not really interested in the quality of the welds. I'm actually planning on doing SEM analysis of the tools post-weld for these experiments...Hopefully I will find something interesting!