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I need to know how to heat treat shear steel. I forged a blade from some that Ric Furrer made down at Harley's. Unfortunately, I missed most of his demo and I have no idea what is to be done about heat treat. I really don't want to scew this blade up so any one who has done it, advice would be greatly appreciated.

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Bob:

 

Do you have any idea what kind of steel it is? If you can get me a close approximation I can help....

 

Scott

 

Scott,

 

Ric put some wrought iron into a Park Carburizing compound and cooked it until it became blister steel, then forge welded the whole stack together. I makes for a cool pattern and follows some really old recipes for making good steel out of iron. Basically a high carbon, high silica steel.

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Mike is right .The even was a double shear steel .The inclusions where worked out by the folding and hammering. Typical uses for the steel were knives , swords, razors.

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Well, there's really no way of being able to tell you exactly without knowing just what it started out as, and how hot it was kept for how long, and how thick it was while being cooked, and how many layers, and how much the carbon was diffused and whether or not the bands of higher C content if any are along the edge, but when I do it, I first Austenitize @ 1400, then if that doesn't harden it, then go up to 1415, and so on and so forth until it does harden, then you can get a pretty good idea of how much C it has by what temp it will harden from, and temper accordingly. If it has a band of HighC™ in the center with soft iron surrounding it, you can keep it a little harder at the edge.

 

I hope that makes sense :huh:

Edited by Jesse Frank
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Thanks for all the responces. I'm sorry that I don't have any more info other than it's shear that Ric made. I was hoping that he'd respond but there is some time before I harden it as I'm still filing.

 

Jesse, what you said does make sense, I think. So basically start at around 1400 and progressivly go hotter untill it hardens? Now a question for that, how do I accurately guess 1400? Normally I take things to non-magnetic then quench.

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That is good practical advice - take it up then quench it and see if it hardens....I would be curious to see how hard it gets.....

 

The hardenability of this material is low..very low.. and occasionally you need to austenize at a high temp to grow grain to increase the hardenability for wider hamons or through hardening.

I would guess that the material I made at Harley's was about 80 points carbon and this would be throughout the billet.

I would suggest an interupted water quench from about 1450-1475 (go to non-mag and then count to five) on a raising heat. Temper at 425 for starters.

 

Years ago I had a tanto made from this material (similar shear steel) and the lab said it had 1% carbon. It would not harden appreciably till I austenized at 1800F and did an agitated saltwater quench. Grain size is a factor in such things.

A lot is at play in these steels and it is a learning curve.

 

Ric

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I beat out a knife from the same piece of Ric's Sheer Steel, and I wasn't as lucky avoiding a couple dead spots. I HT'd in Goddard's Goop, triple quench (first melted the goo, then 2nd and 3rd were in hot liquid) and the edge seems fine - you could push it further, but I didn't feel the need. Simple forge temper right after hardening, cooled in water.

 

58612913-a7b7-028001E0-.jpg

 

58612939-96b7-028001E0-.jpg

 

58612889-a658-028001E0-.jpg

 

 

 

 

When I ground it, I discovered a little bit of seperation between a couple layers, seems to have run rather long and deep. The blade is already down to 1/16 inch thick; maybe half that at the flaw, I'm afraid to grind off any more. I suppose if I wanted to slavage it, I just take off everything south of the inclusion, and just live with a skinny blade, but that wasn't the point.

 

Could just be my poor forging skills, drawing out the blade portion from what started as 1/2 x 3/4 inch bar... is this something that might occur when forging layered steel too cool? I'd hate to slander Ric's work, rather it be my fault... but the steel is great to forge, moves like butter, easy to grind - and lovely to look at. I'll do a simple handle and keep it as a conversation piece. The edge should be fine, would make a great little dinner knife for scout camp.

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Chris,

Glad yo did something with it.

 

It could very well have been a bad weld on my part. That wrought iron had much slag and I only welded twice so more working/welding may have been a better way to go. Such is the way of demonstrations.

 

FYI

I always forge pattern-welded blades at or near welding heat for major reshaping and lower the heat as the blade takes shape......less stress and if it does delamination you have a chance of rewelding it.

 

 

Finish it out, use it for a few months, and then report on how it worked. That flaw is far up the edge and will not be an issue for some time.

Ric

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Chris, thats a nice blade. I noticed a bit of the same thing in my blade so I stopped forging when I had a rough shape and I'm working on grinding it out. I still have quite a bit of material left in the blade. I still haven't gotten to the HT yet. Moving is a big pain in the A$$!

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Must be Ric's fault.

 

Next time, triple refined, and welding heats through the drawing out.

 

I got a seax I wanna make, san mai with shear edge and wrought body. Wish me luck.

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Blister/shear is this weekend's project, if I can get a propane run made tonight before the rain hits. I'll wait until the lightning dies down, though, 'cause I got a problem sitting on ungrounded plywood right under a fume hood that reaches up the stovepipe into the sky, while generating static from my monsterblower and the heat/cool difference the superforge puts out. I think this thing gets hotter than Harley's.

 

 

I'll be trying the blister with packed charcoal dust and leather grindings, as I haven't made the effort to secure some Park Metallurgical # whatever. kaowool and satanite lid on a graphite crucible. Here's hoping it works.

 

2200 degrees for 3-4 hours is what Ric said. That oughtta eat up about half a tank of gas. (I only have the little 5-gal tanks right now - the big ones are prohibitively expensive at the moment.)

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Blister/shear is this weekend's project, if I can get a propane run made tonight before the rain hits. I'll wait until the lightning dies down, though, 'cause I got a problem sitting on ungrounded plywood right under a fume hood that reaches up the stovepipe into the sky, while generating static from my monsterblower and the heat/cool difference the superforge puts out. I think this thing gets hotter than Harley's.

I'll be trying the blister with packed charcoal dust and leather grindings, as I haven't made the effort to secure some Park Metallurgical # whatever. kaowool and satanite lid on a graphite crucible. Here's hoping it works.

 

2200 degrees for 3-4 hours is what Ric said. That oughtta eat up about half a tank of gas. (I only have the little 5-gal tanks right now - the big ones are prohibitively expensive at the moment.)

How thick is your stock?

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Jesse, if he hasn't broken any of it down, it's about 5/8" square. There is some that is at most 3/8" thick. All this is of course provided that he uses the stock that I gave him. :D

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I plan on hammering down the WI fairly thin first, to ensure good carburization. I've started breaking it down, then I ran out of gas this week. My aim is for less than 1/4 inch thick, more like 3/16.

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