W2 grain structure

[Ryan Minchew]

I recently bought an even heat oven and some w2 to start experimenting with. I researched normalizing procedures for w2 and it seems they are all over the map. Some say it needs to drop 50 degrees some say 100 and others say the same temp all three cycles.
I started out with Aldo's w2. Here is a picture of the steel without anything and a piece I took through all 3 cycles of 1575, 1475, and 1400 with a 10 minute hold at each one. There doesn't seem to be much difference between the two if it does the piece on the left is the piece I normalized it may even have slightly larger grain? The opposite of what I want.



Next is a picture after each temp. It seems it went backwards or are the pictures even clear enough to tell?
It goes left to right 1575, 1475, and 1400. Any advice on what I should do?

 

[Stacy E. Apelt - Bladesmith]

The steel came from Aldo normalized and ready to use ( most likely fully spheroidized). Any treatments done will not refine it more. Normalizing and such is done after other thermal events ( like forging) have occurred.

Everything looks OK in your photos. If you want a comparison, heat a piece to 1800F and hold for 10 minutes. Quench and break it. That should show what large grain looks like.

 

[Ryan Minchew]

Thanks Stacy. I should have gone that far. All I've gone by is photos. When broke open the piece as it came it looked like large grain to me just going off photos. I will overheat a piece to get an idea of what large grain looks like in person.

 

[Don Hanson III]

Are the broken pieces hardened?

 

[Ryan Minchew]

Are the broken pieces hardened?

No sir just left to cool to black. Broke the piece then put it back in the oven as by that time it was cooled enough to be to the next temp I had programmed.

 

[Don Hanson III]

The hardened state is the only one I compare grain size in. It will be finer after hardening.

 

[Ryan Minchew]

The hardened state is the only one I compare grain size in. It will be finer after hardening.

Ah okay. Thanks. Seems I've got some more experimenting and research to do. I appreciate it.

 

[Don Hanson III]

It's also much easier to break with fully harden.

 

[Ryan Minchew]

It's also much easier to break with fully harden.

Yes it is lol.
I heated a piece to 1800 and broke it to see what it looks like compared to a as bought piece and a piece I normalized. I can see an obvious grain difference now.

 

[Ryan Minchew]

Left to right. Heated to 1800 and air cooled. Heated to 1800 and parks 50 quenched. Big difference. The far right is a piece that had not been overheated just went from annealed state through the normalizing procedure I did earlier. It and the middle piece look close to the naked eye. Did not expect that.