[Gavin Melville]

I needed to tig a tube of silver steel to the same thickness (5mm) of gauge plate. Everything, and there wasn't much, said to use 312 filler rod, and keep the heat down. Did that and after two weeks of fairly hard use the gauge plate cracked 0.5mm from the weld. I'm guessing this happened at the edge of the heat affected zone. I didn't need any further heat treatment, the steel was hard enough as it was.

I don't have a photo, I've had to re-weld and put back in service. Think a cotton reel with a big centre hole sitting on top of two matchboxes.

I've found that what I buy as silver steel is also known as O1 oil hardening tool steel.

Does anyone have experience welding tool steels?

[big gear head]

Yea, I've welded 0-1, and it seems to break every time. You have to heat treat it after welding. I looked for the correct wire for 0-1 and it was so expensive that my manager didn't want to buy any.

[CMSRacing]

If you have a non food oven the part will fit in, bake it for 20-30 min. per inch of material, roughly, at about 550F, or till it turns a nice blue in a clean section.
That will give you a full temper, retaining a good hardness and bringing back some toughness. I'll post a pick when of some tempered O-1 when I get to work tomorrow.
When welding large pieces, a preheat with a torch can help as well as well.


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[Otto Nobedder]

If you have a non food oven the part will fit in, bake it for 20-30 min. per inch of material, roughly, at about 550F, or till it turns a nice blue in a clean section.
That will give you a full temper, retaining a good hardness and bringing back some toughness. I'll post a pick when of some tempered O-1 when I get to work tomorrow.
When welding large pieces, a preheat with a torch can help as well as well.


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That's one of the many things that makes this place great! On the average welding forum, that question would be obscure subject matter, ignored by and buried by people try to one-up each other with weld pics.

Here, someone knows his s#!t and gives you a solid answer!

Steve S

[Gavin Melville]

I tried that today, welded two small bars together, heated until just blue then let it air cool. Quite tough, but did break at the same place, perhaps 1mm outside the weld.

I'll post some photos over the weekend.

[big gear head]

I think the 0-1 is going to have to be heated to it's critical temperature after welding, which I think is about 1400 degrees. then annealed if you need to work with it more. This might help. http://www.hudsontoolsteel.com/technical-data/steelO1

Have you considered using something else, like 4140?

[CanMoulder]

I tried that today, welded two small bars together, heated until just blue then let it air cool. Quite tough, but did break at the same place, perhaps 1mm outside the weld.

I'll post some photos over the weekend.

Part of the heat treating process you might have to after heating it blue you have to let it cool off and Polish out the blue color than reheat ( anneal ) to a straw color
I have never welded 01 but i have used and heat treated it befor

Kev