Welding Stainless

HELLGAP

HELLGAP

Dealer - Purveyor
I thought maybee this could be done to make handles like hidden tangs and save on metal . The bottom one is a damascus blade that worked perfect no flaws no damage. The CPM 154 I spent at least 10 hours working on these darn blades. I never noticed the cracks until I looked under the magnifying lamp I have. What a complete and total waste of time. All that grinding and heat treated and the price of steel in the toilet. I should have give the steel away for some one to make folder blades. This is a live and learn event . I hope you all learn from my misstake. The Damascus worked excellent you cant even see the weld . The blade now needs to be heat treated. I have no quenching oil can I use olive oil or canola oil to quench the steel is 1080 or 1085 with 15n20 nickle .
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How and what rod did you use. To weld something like this I would preheat the parent pieces to over 500f then either tig or stick weld with 309 or pure nickel filler on the stainless and 7018 on the damascus. Then I would do a anneal type cycle to stress relieve it before it ever cooled down. Your weld didn't break, but, the weld induced stress zone did. The cpm most certainly partially hardened in the weld effected zone. It would be like working a hardened untempered piece of steel. I would make sure to normalize the damascus piece before you harden it as well.

I've never welded cpm 154, but, have welded tangs welded an extension on a D2 tang and welded a piece on some 13c27 stainless. No problems. Also if you do this you would be better off to make the weld a 1/2 or so up the tang instead of right where you did, that is kind of a stress point anyway.

Also, I can also see porosity in your welds. On something thin like this either leave a gap between the pieces about the width of your filler diameter or bevel the pieces. weld one side, turn it over, clean the back side of the weld with a thin grinder disk and weld that side. Make sure to keep you arc gap and if I was using rod or wire I would strike a bit up the tang and then slide to the weld zone to heat my filler a little before I started to fill the actual weld.

You can weld almost any metal, but, when you move past mild steel the procedure is more and more critical.
 
Steel Slaver you are 100 well 99.7 percent correct. The steel was heat treated prior to welding and was welded with 309 rod the damascus 7018 both stick . Mt friend has his own welding company and been welding for 35 years. He told me that as it cools it may crack on the hardened stainless and right where it was at a place that the red stopped is where is cracked probably 10 min after it cooled. It did nt crack right away .I noticed the cracks under magnifacation very tiny hair line cracks. I should have made folder blades and the big blade woulda made a small hidden tang skinner. These were some of my first ever blades I made and was trying to make the most of the steel . I let the blades sit in a drawer for a year , I had a bad feeling it wouldnt work . Lesson learned.
 
I always TIG weld knife blades. I've welded extensions on tangs before but always do that before HT.

When I weld bolts to through tang knives I anneal the tang after wards and check the hardness up the length of the tang.
 
Welding is just not a good thing when it comes to stainless steels...in fact I discourage it with any steel being used for a knife blade. There are just too many issues, and even it you do get it to work, it's likely to fail later. The problem is that you are trying to weld two dissimilar materials, usually with a third material (the welding rod/wire/filler). In my experience trying to save steel by welding (TIG, MIG, or Stick) anything to it, is asking for trouble. It's just not worth the chances you take by doing it.
 
I totally agree Ed it was a idea to try to save me money that cost me 50 bucks and 10 hours grinding and filling. I will never do it again with stainless. Damascus is different especially before heat treat . Those cpm154 blades were RC from 59.5 to 61.5 and cryo . It just was a big waste of time and money ,I wanted everyone to know what a mess they will end up with. Most people would never say anything due to the shame of it but I just look at it like a live and learn experience that cost me one time. Kellyw
 
Oh, I agree that it is not worth it, but, not because it is not possible to do well. But, because it is difficult to do well and therefore just not worth it. The dissimilar metals is not as big an issue as the hardening and stresses created in the higher carbon steel. It really would not have mattered if he would have welded 2 pieces of cpm 154 together using 154 filler, the results would have been the same.The fact that the filler is dissimilar can be a good one if you use one that is elastic like nickel.

Not trying to start a pissing match, just trying to clarify the real issues. Industry does this quite a bit with success, but, with they use strict procedures and controls. Just keeping track of the pieces of paper controlling the weld and dictating the procedure can give me a headach. Often welds are "baked" with various temperatures for up to 12 hours or more, just like a complicated anneal on a tool steel, wrapped in ceramic heating blankets and wrapped in kaowool, with multiple thermocouples contacting the steel and a van full of pids. They are not worried about a broken tang, but, life and death.

Dealing with the stresses created in the hardenable steel will always be a pain, but once they are gone they are gone, unless you do another process to reinstall them. But, then stresses are never visible and it is difficult to make sure they have been dealt with.
 
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Personally, I NEVER weld anything to a tang. My favored method is to anneal and directly thread the tang. To that end I always forge/make a tang that is overly long. IF it becomes necessary to add something to the tang, I always use a mechanical method....and if that's not possible, I start over.

I always cringe when I see folks trying to "save steel" by using a stub tang and then trying to add material to it....in my experience that's just asking for trouble. As I mentioned previously, even if such a process is successful during building the knife, chances are very good that it will fail later....usually in the hands of a customer.
Maybe I'm overly anal about this sort of thing, but I truly believe that a person can spend years and years building a good reputation, and then have it all destroyed by trying to save a few pennies on something. I suppose it's easy for me to say that because I've tried all of those things in the past, and seen how and why they fail..... I just mention it here to try to help others not make the mistakes that I already have.
 
First off, I am not a cutler or a welder, but I have heard some suggestions on this subject over the years.

In Madison, we have a company called DEC, or Dairy Equipment. They produce those big stainless tanker trucks for transporting milk. They have welders, and granted, these guys are the "cream" of their profession, no pun intended. Obviously, stainless steel can be welded.

Additionally, in the early 1970s many custom bike builders used an alloy called 4130 chrome molly for frames to save weight. There were numerous accidents when the frames shattered along the welds.

The issue wasn't the alloy, but the concept of heat relief. Is it possible that this technique could be of help to cutlers?
 
That argument does have some merit to it....but in this case the stainless steels that we are talking about are martinsitic (spelling?) stainless, which means they possess extreme air hardening characteristics. Most tank applications tend to be 300 series stainless, which is a non-hardening variety, and rightly so for that application.

The 41XX series steel is a completely different animal, that is often confused with stainless because of it being labeled "Chrome/Moly" steel. 4130 is not a "stainless" steel.

I'm not trying to chastise, just pointing out the differences versus the knife steels.

My stance is that welding (TIG/MIG/Stick) on steels that knife blades are being produced from, is just not a good thing, and in the long run, doing so will cost an individual more time and money than if they had just just enough of the given steel in the first place.
 
EdCaffreyMS said:
I'm not trying to chastise, just pointing out the differences versus the knife steels.
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Oh, have no fear, I never take offense in a debate, or when folks are thinking out loud to solve a problem.

If anything, I was hoping to jog some expert metallurgist here or a cutler who had a similar problem.

And of course, it is common for me to serve admirably as a bad example.;)
 
I agree Ed I bought the stainless in differnet lenghts not knowing what lenght I should buy to save money and screwed up the blades. There is a huge difference between a milk tanker truck and a heat treated knife that undergoes 1800 degrees for and hour and then dunked in -270 degree liquid nitrogen. Milk tank trucks are welded in Regina by a bunch of guys who dont even have welding certificates for a journyman. I know several of these guys. Yes they can weld but welding a knife is a different thing all together, Im with Ed and I threw this thread out there to show everyone not to do this to save a few bucks . As far as the damascus blades I welded I think its ok because they were not heat treated . Before I did this. They are all final ground down ready for etching . But from now on if the damascus isnt 8 inches or longer it will never be in my shop.
 
I agree 100% that trying to save money by welding an extension on a piece of blade steel is not worth the time or is it a money saver. Plus it will never be as strong as a a solid parent piece. Just trying to point out it is possible and that the main issue you have to deal with is the stress. More welds fail in many applications due to stress than from poor welds.

Reasons I have welded on D2. 1 I broke the end off a threaded hidden tang. (Threaded pre HT and yes, I would have been better off to have drawn it way back before I tightened the butt cap way to tight.) Another, I decided I wanted a threaded cap after HT and yes, I could have soldered threads on but, I could also weld threads on and have it be way stronger than any soft solder joint and know that that the knife failing at those points just was not going to happen. My opinion. But, I have a mig, a tig, stick and every rod I could want. Plus I have already bet my life on my welds many many times.
 
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