matthewfromers

a problem about forge welding

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Hello everyone, I'm Matthew, and I'm writing to you from Italy.
I am 33 years old and for about a decade I enjoy making knives.

After I built a Japanese bellows and had some experience with it, I moved to making some forge welds (something that had never come out in an appreciable way),
these are the results after welding and acid etching.

After this passage, everything seemed to me to be properly welded and no obvious signs were present between the metals or spaces. So I proceeded to heat the pieces and continue to work them, this time in both directions, to lengthen what was the package. But out of 5 tests, 4 have (unfortunately :unsure:) been opened.

The method I used for welding in the forge was:
remove oxides and slag with a sanding machine and leave the metal "naked". Clean the metal with a nitro thinner.
Clamp the pieces and weld them with the welding machine, add a handle in 2 cases. W.ith the hot forge, bring the package to the red color and put borax, put the package back into the forge and bring the temperature up to the white (in a couple cases up to sparkling white).
I've removed and tap immediately with a 2kg hammer, repeating the operation 2 more times (add borax, reach the temperature and beat).

Everything look really cool but when i try lengthen the packege... it's open it up.

I've try to weld forge iron (s275jr) and 1050 (from a spring truck) and iron and w1 steel (from an old file).

I ask for support, advice, or any documentation that can help me understand where I'm wrong. Heartfelt upfront. In addition, I apologize if my post is not placed in the correct forum section.

:rolleyes: thank you, from Matthew

 

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WhatsApp Image 2019-09-01 at 15.12.10.jpeg

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WhatsApp Image 2019-09-01 at 15.12.09(2).jpeg

WhatsApp Image 2019-09-01 at 15.12.09(3).jpeg

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Hi Matthew,

Welcome. Someone with more tech knowledge will doubtless provide a link to the “read this first” article. 

Based on the pictures, the welds don’t look too bad. Sure, there’s a slight delamination, but I’d suggest grinding it out and continuing to work the piece. It may be that the delamination is not critical and the rest of the weld is good. A couple more heats to welding temperature while working the piece may give you a viable billet. On the face of it, I don’t see anything immediately wrong with your method. But it is Monday morning.

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Hello Neal, thanks you for the first reply!

I realize I am not very practical about the forge weld and the delamination of the layers.

By delamination do you mean this area here (red marked)? Or are there are others that I can't recognize? thank you very much for your contribution

 

:rolleyes: Matthew

delamination-01.png

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Yes, that's right. Based on the picture, it looks like the rest of the weld could be good. I'd try removing the affected area with an angle grinder and working the piece at a welding heat to see if you get further separation. if you do, then  the entire weld is bad - but based on the method you've described I'd be surprised; I do pretty much the same and it works fine. Occasionally I get minor delamination at the end of billets where some scale has crept into the weld - I simply grind these off and forge on.

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Dear Neal,

after taking the photos I tried to work the pieces, the one marked with the red of is literally open, detaching completely. While all other packages have opened.
I assume at this point 2 things:
- although they appeared to be correctly welded in the forge, in reality they were not. (and it would seem strange to me because I reach temperatures consistent with what is required).    

-I'm working the package after welding incorrectly, perhaps working it at lower temperatures. (never below red).

All this is so frustrating.... :unsure:

 

Thanks for your support Neal,

 

Matthew

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I’m no expert in any way, but I’m also a little confused by the weld that failed. Was it a stack billet or a lap weld. From the cross section, it looks to me like it needed a scarf on the ends of the darker piece.

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I was talking to a nice gentleman in another forum and he suggested that the biggest problem was the choice of truck spring steel.
For the chromo content that could be added to the alloy. In fact the test in w1 seems to be better and has not delaminated.

I enclose a photo, I'm trying to use it to make a small Japanese spear planer.

Looks like there's not delamination or other strange stuff.

1944325052_WhatsAppImage2019-09-03at08_32_08.thumb.jpeg.08477150cf8897f9d53beae4c3a42744.jpeg

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The gentleman you spoke with is probably correct. I've heard many stories about the same problem trying to forge weld leaf springs. There's people with much more knowledge of this subject than I have and I'm sure they will be around before too long. I would try welding up some  high and low carbon steels. I'm not sure of the European designations but in the US they are known as 10xx series steels like 1095, 1060, 1080, etc. Mixed with some lower carbon content layers they are much simpler to weld up. All in all nice work and glad to have you here.

Pnut

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The pleasure is all mine to be here!
The gentleman in fact advised me to try with 15n20 and 1075 (which we simply call c75 here in Italy).
The biggest problem, here, is to find materials of considerable thickness, even normale iron retailers usually have nothing with a higher percentage of carbon than (1040) c40e in Italy.

So I've usually find out steel from knife maker supply!

Thaks for your reply Pnut.

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You can always make blades from low carbon everywhere but the cutting edge. I'm starting a wrapped eye tomahawk out of mild steel with a 1060 cutting edge. 

Pnut

 

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If fact the aisi 1060 didn't contain chrome!
But probably my truck spring contain some of that :unsure:

I would like to see your tomahawk! I look foward to creare an axe in the same way

Matthew

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I still have to make a drift or mandrel to wrap it around. It's another on the growing list of projects. I hope to get to it soon. 

From what I've heard here and elsewhere spring steels can be aproblem to forge weld. I stick to low alloy carbon and mild steel because I don't have much experience when it comes to forge welding, when it comes to blacksmithing in general. I've only been actively forging for less than a year but have been researching it for a bit longer. Truth is you have much more experience than I do so take anything I say cautiously. I try to not pass on bad info but I've been wrong before and am sure I'll be wrong many more times. Happy forging and remember it's supposed to be fun.

Pnut

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Dear Pnut, don't worry about, I'm very glad for your support and I will for shure try to weld some other material together! And I will keep you informed! ;)

As you rigthly said: " it's supposed to be fun ", and, luckily, it is a lot! <3

Matthew

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One aspect of forge welding which most newbies fail to recognize is that in order to forge out an object that has been forged welded, even if forge-welded extremely well is the fact that the metal itself will move at a different rate because of the difference in materials. this can create a shearing aspect between the layers.  So the initial or majority of the forging is in fact done at near welding temperature. 


On the failure of the seam/end on that photo.  there is no scarf.  this is known as a shearing point unless you finish off the weld. You can clearly see where the spring as it was welded on created a direct cut into the parent bar. 

And yes it did delam at the end as there was no metal there for the welded in section to adhere to. 

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5 minutes ago, jlpservicesinc said:

One aspect of forge welding which most newbies fail to recognize is that in order to forge out an object that has been forged welded, even if forge-welded extremely well is the fact that the metal itself will move at a different rate because of the difference in materials. this can create a shearing aspect between the layers.  So the initial or majority of the forging is in fact done at near welding temperature. 

Thanks for your kind reply!

So do you suggest me to work the package and proceed with the elongation at a temperature close to the welding temperature? Beyond the orange color?
Thanks a lot!

 

Matthew

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Yes, till you are fully welded and you are ready to forge into your final shape..  anytime you are doing a major forging action this need be done at near welding heat. 

Having a keen eye as to what the metal is doing while you are working and adjusting is key to success. 

a scarf can be applied in different ways. a Square edge weld will create a shear point.  Scarf the end next tiem that will be near the non open end. (towards the handle). 

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Look up extreme close up!!scarf welding!! On YouTube it's on Joey Van der Steegs channel.  It's a simple concept but one I am having a hard time putting into words.

Pnut

 

It's basically upsetting the ends where the layers will meet. There's a little more to it than that but I could show you so much easier but it's not as easy to explain without a picture.

Pnut

There's a PDF you can download on the ABANA website called controlled hand forging that explains it. 

Pnut

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Pnut, why do you keep insisting he use mild steel for his blades? there is no low/hi layering to damascus, carbon migration prevents that.it just make a billet of medium carbon steel when finished, plus the expansion and cooling rates differing can be asking for other problems, which for hi/low carbon stock will be minor I admit

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2 hours ago, pnut said:

 

It's basically upsetting the ends where the layers will meet. There's a little more to it than that but I could show you so much easier but it's not as easy to explain without a picture.

 

Pnut

Upsetting is not the key.  Upsetting is to replace the metal you will lose in the welding process. 

It also helps to blend the weld some as it gives you a little extra material to work with.

The lap scarf most people show is what I call a European lap weld scarf. 

 

There are as many scarf varieties as there are Smith's. 

 

I personally use what ever scarf is required for the type of weld needed, flat, 90, 45, T, jump, cleft (gullet,) wrapped, split etc, etc.

 

In simple terms a scarf or the important part is the very end which needs to be as thin as possible with no square corner.

The European scarf now is the most popular and shared the most.

It does not mean it's the best. 

 

Wrought iron could be welded in ways that would make a Smith using mild steels sick to see or contemplate. 

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2 hours ago, Steve Sells said:

Pnut, why do you keep insisting he use mild steel for his blades? there is no low/hi layering to damascus,

 

 

7 hours ago, pnut said:

You can always make blades from low carbon everywhere but the cutting edge

I was suggesting a san mai type blade. He said he had a hard time sourcing high carbon steel. 

Pnut

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San Mai method is much harder than a normal laminate to get solid, because there is less re working of the weld zone to secure the bond.  A regular billet gets drawn out and as re stacked which reinforces the welds as we proceed.  So unless one used over 1 cm thick layers to start with, you need 100% accurate welding, there is no room for errors to be corrected, plus lack of mass in thiner layers loses heat faster

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I agree totally with Steve.  San Mai  with a taco type arrangement is tough to get it done properly. 

A multi-facet build up (layering of 4 or more for middle, back, sides) in some ways is easier. 

On a slightly different note"  A San Mai blade or any blade that has a sandwich cutting edge has to be worked evenly from both sides or you will offset the core steel. 

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The first bunch of times I tried a "taco" type arrangement that is exactly what happened. The hi carbon steel didn't end up where it was supposed to be. 

Pnut

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