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Saul Kokkinos-Kennedy

Forge welding stainless and "fire" pattern damascus WIP

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My most recent job has involved working with a blacksmith, who happens to have a power hammer, and has been nice enough to let me use it in my spare time! It's been really fun, and is a lot nicer than trying to hand weld damascus.

 

I thought i would show the processes I've come up with based on the information from this and other sites. I would really appreciate any tips, as this is my first time doing stainless san mai, or making big PW billets.

 

Finally decided to splurge out and buy some proper steel. I went with 1084 (115mm*13mm), 15n20 (50mm*2.4mm), 1045 (55mm*10mm), 416ss (22mm round), and 431ss (65mm*8mm). Not ideal sizes, but was all i could find for a reasonable price, plus i have the power hammer to deal with the thicknesses.

 

Here is the first billet of 1084/15n20 tacked together with handle welded on. Decided to double up the 15n20 layers due to how thin it was.

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Here is the san mai billet 431ss/1084/431ss being welded all the way around. Before welding the seems i cleaned all mating surfaces, and immediately after the last 60 grit flap disc pass i sprayed them down with WD40

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Here are the three billets i'm gonna work on. 1084/15n20 PW. 1045/1084/1045 san mai, and 431/1084/431 san mai.

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Here is my newly finished forge, heating up the first billet. I'm pretty pleased with it, and find the adjustable arm out the front quite useful

PICT0550.JPG

Edited by Saul Kokkinos-Kennedy

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Here's a quick clip of the initial weld.

 

Here's a pic of the seemingly successful welds on the 1084/431ss san mai billet.

PICT0541.JPG

 

Drawn out billet of 1084/15n20

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Billet ground clean, cut up and re stacked, with two solid pieces of 1084 each side of PW. I've saved some of the original PW billet to do something different with...

This time the billet was forge welded as normal, but once i was certain the welds were holding i flipped it 90 degrees and forged the sides out.

PICT0557.JPG

 

Drawn out again, cleaned, and cut into 5 pieces ready to be forge welded again.

PICT0599.JPG

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Just wanted to say a big thanks to Dave Stephens for the amazing presentation of how to do this pattern. If you haven't seen it check it out here: http://www.bladesmithsforum.com/index.php?showtopic=23706

 

View of the end of the bar after forge welding. Lines are beginning to distort in an interesting way, although it's looking a bit rounded for flames. It had totally evaded me that by placing the pattern in the middle of the bar, i would have the effect of bulging out rather the being distorted inwards. I think it will become more flame like after a few more welds.

PICT0631.JPG

 

Here is an etched piece of the 431ss/1084 san mai. As you can see there is a bright line between the steels. Does anybody know what might cause this? looks quite nice

PICT0627.JPG

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i find it useful to use a small fire brick off cut in the forge to hold the billet off the bottom. This allows the flame to still "vortex" around the piece. I use the adjustable stand mounted to the forge to position the handle of the billet to the same height.

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Here's my first commission on it's way. It's a 416/1084 san mai kitchen knife.

Distal tappers forged, profile rough ground and ready for heat treat.

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Successful HT! almost finished bevels, just had to etch for a quick look. handle is 125mm and blade is 240mm

PICT0517.JPG

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I am really looking forward to seeing this done. What a great start.

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I'm curious why you welded the San Mai billet all the way around. What is the purpose of that? I'm guessing the line is the weld bead. Either way really cool stuff, thanks for sharing.

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Thanks guys. Unfortunately any progress is some time off as i'm recovering from a knee fracture.

 

Matt, the reason for welding all the way around is to prevent any oxygen from contacting the stainless steel. For some reason SS oxides are not dissolved as easily, or at all, by flux. Maybe something to do with the high content of chromium in the scale?

 

The bright lines are not the weld, as even when i cut the billet through the center they were still there.

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Wow! Awesome post and very nice work. Love your forge and am impressed with that unusual pattern and the SS welding, still on my to-do list! Not certain about the bright line but also really doubt it has anything to do with your bead weld - looks very consistent. I'm sure some of the folks here with better metallurgy knowledge will give you an answer soon. Clint

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Hi

Welcome - always nice with a good WIP - and some nice knives on the way cant wait to see that kitchenknife finished - keep up the good work

 

...... have made stainless / carbon laminates myself using 01, 416, 1.4034, 316 and A-ebl and different carbonsteels 1095, uddeholm 20c and white paper steel ......I read somewhere that the white line is a result of carbon migration ? Have never used 431 steel but it should not be that far from 416 steel.

I have started using pure nickel 0,010 / 0,005 inches between layers to stop carbon migration - works fine even with stainless.

The white line appears brighter when using plain carbonsteels ( 1095, 1080, uddeholm 20c ) but is not as clear when using carbonsteel with crome ( 01, 80crv2 )

The carbon migration and the thickness of the "migration line" also depends on how long soaktime you are using .....I usually soak the billets for 15 - 20 minutes after the first weld ....

 

This blade is 1 % carbonsteel and 1.4034

IMAGE_538.jpg

 

One blade with same steel as above ( left ) and one with 1.4034 and 01 .....

 

 

IMAGE_487.jpg

 

 

and 316 stainless / 20 c and pure nickel

 

IMG_1098.JPG
Lars

Edited by larsjacobsen

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Thanks Lars. Interesting to hear what steel combos you have got to work together, and very nice blades. Your width of exposed carbon on the edge looks much better than mine, mine ended up being a bit higher than i would have liked. Gonna have to play around with different starting thicknesses.

 

I could be wrong, but i believe the 3% nickel in the 431 stainless should be enough to stop carbon migration, and the carbon migration on the 416/1084 kitchen knife looks cloudy like a hamon, not a straight line. Again i could be wrong?

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Loving the WIP! That's some really nice work!

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great wip Saul.......

 

what do you guesstimate your forge time to get this stack to weld temp ??

 

 

post-34118-0-20679600-1426576387.jpg

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Cheers John.

 

Rob, i'm not entirely sure, but i'd say the forge takes about 10-15 mins to get up to temp, and then i put the billet in which took about 15-20 mins, but i usually leave it another 10 from the time it looks like it's at temp, just to make sure the middle is not colder, especially for the first heat. Again only estimates, and i crank the forge up to 10ish PSI at the beginning because i don't like waiting

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Awesome!

 

Great job man.

 

Looking forward to seeing what you make!

 

Dave

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I'm very very interested in carbon stainless laminates.

Would you mind sharing what temps and soak times you used for the welds? I have the general process down, but specifics on a place to start always help lol.

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I could be wrong, but i believe the 3% nickel in the 431 stainless should be enough to stop carbon migration, and the carbon migration on the 416/1084 kitchen knife looks cloudy like a hamon, not a straight line. Again i could be wrong?

I have been told by a reliable source that it requires a much higher nickel content than that to stop carbon migration. 3% won't even slow it down...

 

Very cool projects!

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I'm very very interested in carbon stainless laminates.

 

Would you mind sharing what temps and soak times you used for the welds? I have the general process down, but specifics on a place to start always help lol.

 

Nevermind lol...I missed your previous post with your times.

 

Are you determining temps by color and the look of any flux you're using?

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Thanks Dave! Wouldn't be possible without your amazing tutorial.

 

Interesting to hear George, wasn't sure as i said, I've come across allot of contradicting info. Still curious as to what that bright line is on the 431, as it seems quite different on the 416?

 

Anderson, on the first SS billet i just used the same settings on my forge that i normally forge weld at, and soaked for about 20mins at temp with a flip in between. I didn't use any flux as i was worried it might capillary into the tiny hole i left for gas to escape.

 

On the second billet i had my thermocouple set up which read about 1250°C. I also made sure i was at or near welding heat when i was doing allot of drawing out

PICT0621.JPG

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Looks awesome! I've had to double up on 15n20 before, too. I've heard it can be a bear to weld to itself because of the high nickel content and the oxidization, but it looks like it worked fine for you too.

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Thanks Dave! Wouldn't be possible without your amazing tutorial.

 

Interesting to hear George, wasn't sure as i said, I've come across allot of contradicting info. Still curious as to what that bright line is on the 431, as it seems quite different on the 416?

 

Anderson, on the first SS billet i just used the same settings on my forge that i normally forge weld at, and soaked for about 20mins at temp with a flip in between. I didn't use any flux as i was worried it might capillary into the tiny hole i left for gas to escape.

 

On the second billet i had my thermocouple set up which read about 1250°C. I also made sure i was at or near welding heat when i was doing allot of drawing out

attachicon.gifPICT0621.JPG

 

Very nice! What temp do you normally forge weld at?

 

I have the same pyrometer btw...works beautifully in my heat treat oven, and I can move it around the shop with ease to verify temps elsewhere.

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Not entirely sure what temperature i normally forge weld at, as i use the flux as a temperature gauge. I would say a touch colder, maybe 1150-1200ish °C.

 

Good to to know there are other people using that thermocouple. Wasn't sure how accurate it would be. I've had trouble getting the K-type fitting on probes, and ended up buying a K-type and rewiring the probes to fit, seemed to work well until i burnt through them by letting the forge get too hot. So looking to buy some new ones. Could you send me a link to the probes you use?

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Very nice wip, lots of good info! Can't wait to see the chef's knife done!

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Not entirely sure what temperature i normally forge weld at, as i use the flux as a temperature gauge. I would say a touch colder, maybe 1150-1200ish °C.

 

Good to to know there are other people using that thermocouple. Wasn't sure how accurate it would be. I've had trouble getting the K-type fitting on probes, and ended up buying a K-type and rewiring the probes to fit, seemed to work well until i burnt through them by letting the forge get too hot. So looking to buy some new ones. Could you send me a link to the probes you use?

 

http://www.amazon.com/gp/product/B00NWPRWYM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

 

This is the kind I've used to good effect in my shop. They wear out of course...I just got new in to replace the one in my oven. But they do work.

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good work, man! this is a lot of stuff to think about.

 

I have always wondered, is there a good way to get a contrast with two stainless steels used in pattern welding (two steels that would make good blades, of course) otherwise it would be easier to just sanmei.

 

thanks for sharing.

kc

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