First Forge Weld, San Mai

[philb86]

I started a journey into learning how to forge, and decided it was time I give forging a knife a try.  I have done many stock removal knives, but want to take my knife making business to the next level and start learning more.  As usual, I jump feet first into things and thought to myself, I want to do a stainless san mai.  I dont know if I got lucky, or all the steps of the initial prep work led to have a first successful forge welding experience, let alone stainless to high carbon.  Once I had the billet finished I cut out and ground the profile, and finished the knife, and made a leather sheath to go along with it.

410 Stainless and 1095 HC

Maple burl and black palm scales with orange and white G10 liners and orange G10 pins.

8-9oz leather sheath made in house as well.

Let me know what you all think.

 

[Daswulf]

That turned out nice Phil! 

[LeeJustice]

Nice work.  I have a question.  Since most of it is stainless then you forgo the hardening quench which you would do if it was all high carbon steel?

[ThomasPowers]

Looking at that I would say most was NOT stainless!  The 1095 for the edge is the main part of the blade and the stainless the "ornamental" part near the spine.

So PhilB86, did you forge to shape after welding?  It looks to me you just used the billet for stock removal and so didn't have any of the stainless lower where the most grinding occurred.  Perhaps doing a simple forged in bevel on the billet next time would include more of the outer layer into the blade when you got to grinding.

Great blade and extra nice leatherwork!

[anvil]

Thomas, I got the same impression that he forged the billet then stock removal for the blade.

Nice knife and congrats on the forge weld!

[Bob Brandl]

If I'm reading Lee's question correctly, you don't skip the quench. You HAVE to get to temper as fast as possible afterwards, though. Like, immediately fast.

[LeeJustice]

Well, I was assuming that the middle of the sammich was stainless, making the bulk of it after grinding stainless.  Thomas disagrees, but I am still waiting on Phil's reply.  I asked because you are not going to harden stainless, just the high carbon steels.

[ThomasPowers]

And so you would NOT make a San Mai billet with the center LC  stainless.  The grinding and hilting indicate a strong familiarity with blade making; so I would assume it was done right rather than wrong.  Why go to the effort of doing a nice handle and sheath if the blade was soft?  I always check my blades for hardness before finishing them.

[Frazer]

410 is an air/oil quenching, martensitic SS alloy. Many kitchen knife sets are made with 410. Based on the etch I'm assuming the centerpiece is HC and sides are stainless, but either way would be fine. 

Oh, and that's a beauty of a knife/sheath. I really like that handle.

Edit: Using the HC steel for the edge is certainly the preferred way of doing things. According to my Machinery's handbook, the hardness of 410 after tempering at 400F is 41 HRC. That is relatively low.

Still, it is used for some commercial knives so I stand behind my "either way would be fine" statement.

Edited May 14, 2021 by Frazer
Added clarification.

[philb86]

Thanks all!

I really have to turn my notifications on so I know when there is a reply.  I will start by answering ThomasPowers.  You are correct, I forged the billet and then profiled the billet that I had made.  The make up is 1095 sandwiched between two pieces of 410SS.  I am planning on forging the bevels in once I get myself a little more consistent on making the billets as my second attempt tonight to make another billet of the same make up above, I found a spot where one side of the stainless did not weld to the high carbon.  I started to grind it out and it got to the point that I needed to come in for the evening, a little disappointed. 

It is a fully hardened blade, however I did an edge quench, to ensure that I did not split the billet.  I have seen a good bit of cases where when the whole entire blade is quenched and the stainless actually rips the high carbon apart right down the middle.  After I finished grinding out the unwelded portion on the current billet I made this afternoon, I may end up cutting in a preform and then forging bevels into a finished knife profile.  All depends on how much more I have to grind out of the billet, as the majority was welded.

 

Bob Brandi, as long as you thermocycle the blade properly, there is really no need to rush it off to tempering after quench.  I do however do that immediately after for any knife that I make.  I have blades that were quenched and not put in into temper until a few days later, and there has been no ill effect.

Edited May 17, 2021 by Mod30
Remove @name tag

[ThomasPowers]

Please no AT signs!   They mess up the forums software!!!!!

I had a student who normalized a blade---thermal cycling means squat as all heat treat steps are thermal cycling----quenched it and left it on a rag on his workbench with out tempering---found it in three pieces the next morning.  Depends on the alloy and how the hardening was done but doing a snap temper is just good insurance in my mind.

[philb86]

Noted, no AT signs. 

I have heard of cases like that, never experienced it though myself.  I dont disagree with it being good insurance, as I said almost always I temper after reaching ambient after being quenched, just my routine.  Was your students blade forged, or stock removal?

[Steve Sells]

I had an O1 dagger shatter after taking a phone call shortly after hardening, I only salvaged a boot knife from it

[Bob Brandl]

While I have only had a blade shatter once (52100) after waiting too long to temper, my comment was specifically regarding a stainless san mai. Several bladesmiths I know have had the stainless peel right off the core. I normalize no fewer than three times, but with stainless I don't mess around and wait.

[ThomasPowers]

Good habit to have and it won't hurt other alloys!