Help!! Bruce Bump or anyone on damascus...

anvilring

anvilring

Joined
Nov 29, 2000
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Have a look at the link below. I "think" my trouble is once I did the first initial weld, I went straight to the power hammer and my steel was still way too hot! Notice that the cracked edges are on the top layer of 5160; still the hottest layer, as the ones on the bottom against the anvil cooled much quicker. No problem with those layers. Could it be that I'm attempting to forge at what is still critical temp with too much (i.e. 20# Little Giant!!) force?? I ground into the side in one photo and the weld is good. I used a square faced 5# hammer to weld with and I'm not hitting it that hard at all really, those cracked edges are from the power hammer yes??

I'm back out to the shop...

thanks anyone who can shed a little light here....

regards, mitch

http://www.flex.net/~mitchwilkins/homepage/page6.htm
 
Hi Mitch, I think the 5160 cant take the welding heat without burning. Ive been told to stay away from it for damascus. What kind of flux do you use? I would think it should have protected the steel better. Ive seen cracks like that from overheating. Do you use a pyrometer? Are You using propane or coal? I do forge and draw billets at welding heat but sprinkle just a fine dust of borax on it to keep the surface from roasting.

When you speak of critical heat do mean welding heat? Critical heat is barely nonmagnetic (1500f approx.) and ready to quench. Welding heat is 2300f

You would have better luck with the old standard 1084 and 15n20 or any of the 10x steels and l6. o1 and mild steel made Bill Moran famous but the edge will roll more than likely. There is too much carbon migration unless a very small amount of mild steel (1018) is in the stack.
 
Lets see,5160 is not the problem as I weld it all the time.First problem I see is get rid of the flat faced hammer when welding,use a rounded face and make sure you overlap each weld with the next hammer blow.You see how the outside layers are squished out farther then the middle layers,you are not hitting with enough force when stretching out the billet to get all the way through the middle of the billet,when you have this problem starting be sure to hit the edges to keep the billet squared up.Make sure your anvil face is warm when welding so it doesn't suck the heat from one side faster than the other as this will cause uneven stretching and welding.The looks of the steel you are showing is a result of one of two things either you got the billet way way to hot(as in sparks coming off it before welding) or you stretched it under the hammer and let it cool off to much before you quit hitting it.If you look at the pictures good you will see that the outside layer is not the only one with these breaks in it,this leads me to believe that you got the billet way to hot as the steel is burned in these layers which you see in the large grain in the breaks.Try rotating the billet in the forge and not letting the flame hit in the same spot all the time,and try welding at a lowwer heat with a rounded face hammer,If you have to try a thinner billet to start out with so the heat gets through the whole billet faster and evenly.

Just grind off the edges of this billet untill all the burnt cracks are gone and grind the rest of the billet clean ct it and add a couple pieces of new steel on the outside and try it again.It will be a lesson to learn in what not to do and how to correct the problem if it does happen again.Old files will do this the easiest to you so watch using them,they work great but burn easily if not good quality ones.Also don't try the weld on the whole billet at one time,do it in a few stages and weld a little bit at a time.The power hammer is not the problem,if you had the billet welded good to begin with the hard blowes woulden't hurt,heck with practice you can weld under the power hammer and forget the hand hammer welding completely.

Vince Evans like a 5160 and L6 blend for his swords and I have welded it with cable and a lot of different types of steel myself so I really don't think the steel was the problem,unless you used old steel springs and didn't normalize it first ,I have tried this and found that a hardened steel doesn't work as well as when you normalize it or anneal it first..

Just keep trying and you will get it,
Good Luck and hope this helps,
Bruce
 
It also looks pretty obvious to me that you got it too hot. I consistantly stick sound welds at around 2100F-2200F so don't be afraid to drop your temp and save your steel. If you are not hot enough, you may have to take another weld, if you are too hot you are pretty much done (as you have learned in this case) So which is the safer bet? :) 5160 will weld fine, but it always had a different look to it in the final product that did not appeal to me and some steels weld easier.

I highly recommend Bruce B's suggestion of 15n20 and a 10XX series. This stuff will weld like a dream, look beautiful in the etch, and perform like a champ. I would be a little more careful mixing L6 and 10XX however, due to the great differences in heat treating requirements, and expansion rates.

I agree with Bruce E. on the force of your blows going evenly into the center of the billet and definitely agree with the idea that you want to heat it as evenly as possible. However, I have used flat dies for welding my entire career and have come to prefer them, over the rounded dies, for anything but extreme drawing operations, another one of those things that come down to what you are used to.

Bruce E. Is also correct that hand welding is not a necessity, although I have found that 25lb. Little Giants can slap the steel around more than weld it. Welding works off compression not just hitting, so the more your blows squeeze, and the less they rap, the better the welds. This goes back to Bruces advice about deep penatrating blows. This is why presses, and very large hammers probably weld the tightest. If you find the smaller power hammer is not "squeezing" enough, I would go to as large a hand hammer as you can handle and mash that thing together first and then go to the Little Giant.
 
Max recommended forging temperature for 5160 is 2150F. Of course you'll go a bit higher to weld. It certainly does look like overheating. The bigger the billet the more significant the difference between power hammer and power press. The press will work the center of the billet while the blows from the hammer tend to work only the outside.
 
This is a big help! I've got a damned pyrometer but have yet to get a thermocouple and an "inconel" (sp?) tube for it. I'm breaking down my forge for a rebuild begining today, it's been two years since I've done anything to it and having added a burner, re-welded two holes, changed the opening ect... it's time for new kaowool and refractory as well as a new method of building the furnace "mouth" (opening) I'm learning! I'm learning! I'll report next week on my progress with this problem but again thanks to you guys for all the help!

P.S. I know you all problably know about Ron Reil, as far as I know it was he who perfected the home built ventori burners we all use in our forges and now on his web site, he's added three others: the Mongo, and Mini-Mongo burners which are incredibly hot! Such a cool site and he works hard to help others! Not a bladesmith but he knows his stuff. Here's a link to his home page and I'll post a seperate thread for it as well......

compliments and regards, mitch


http://www.reil1.net/
 
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