Posted 25 October 2010 - 01:23 PM
Posted 25 October 2010 - 06:58 PM
I've been using 416/1080 or 1084 with good success, and more recently have been doing it with 416/Mosaic Damscus. Others are having good success with 303SS. It takes some playing around with to get it right...especially in the annealing area. Anyway, here's how I do it...
1. I surface grind the mating faces of the core and the 416 exterior pieces to 120 grit.
2. I clean all the mating surfaces with acetone
3. Sandwich the billet (1084 in the middle with 416 on each side) and clamp it tightly together.
4. I then MIG weld the entire edge, all the way around (basically the 416 becomes the exterior of a "can"), weld on a handle and into the forge as quickly after MIG welding as possible.
5. Bring the forge to approx. 2350F (I have the forge running while I'm MIG welding the pieces) Then get the billet into the forge and let it soak for 7-12 mins once it reaches temp.
6. I weld by running the billet gently through the press ONCE,
7. Allow the billet to cool a bit, then using an angle grinder, I grind off all the MIG weld material....it will be easy to see when you get it all, as the core will turn blue, and the 416 will remain "shiny".
- The mating surfaces MUST be FLAT, TRUE, and CLEAN.
- Make sure that the pieces are tightly clamped together before MIG welding.
- Once the edges are completely MIG welded, do the forge welding as soon as possible...I once left a billet after MIG welding the edges overnight, and then tried to forge weld it the next morning. When I went to grind off the MIG, the billet just fell apart, and had a shiny black coating on the insides of the 416. The only thing I could come up with was that my MIG weld had a pin hole in it, and oxygen got sucked in as it cooled, then oxidized up when I put it in the forge the next morning,
- Once welded, this material will not anneal as 1080 or other carbon steels do! The only way I have successfully annealed this type of material is to put it in my heat treat oven, set at 1350F, hold for one hour, then allow it to cool overnight IN THE OVEN.
- There are several other little "quirks" with this material in the heat treating that you will have to work out...some of which I still have not fully figured out.
- Finally, keep in mind that due to the temp and soak time required to weld this stuff, there IS going to be carbon migration. This will be evident when the material is etched....there will be a line that looks somewhat crystallized, which will be an area of almost complete decarb. The next line will be dark black, which is where the carbon "piles up", and there will also be line fading up into the 416, which is carbon diffusion.
It took me about 6 months worth of work to figure out the above information, and there are still a lot of things I don't fully understand about this material.... I had to make/destroy about 8 blades of this material before I got one that I was willing to sell. Others have done it by wrapping in heat treat foil, and I'm sure there are other details that differ from maker to maker....but this is how I do it, and by doing so have a very high success rate.
I think the person that likely knows the most about creating this type of material, and making great blades from it is Burt Foster....hopefully he will jump n here and give his input.
Posted 25 October 2010 - 07:26 PM
Anvil Top Custom Knives
Posted 26 October 2010 - 06:29 AM
Posted 26 October 2010 - 12:49 PM
Thanks again mate.
Posted 26 October 2010 - 03:42 PM
I have used 300 series SS for this process. If you intend to surface grind your pieces, remember 300 series is not magnetic (the finished product will be though).
Welding the seams may be done with TIG, MIG, or stick welded.
Hank Knickmeyer said it best when he stated at a Hammer-in -- Whenever you weld 2 different pieces of steel together, you don't end up with what you started with.
The point being that you may start with 1095, but what you end up with may be something different. The more time spent at high temperatures the faster the carbon diffusion will be, so the methods you use and the time it takes you to do this will all play a role in what you end up with and how it will perform.
Posted 27 October 2010 - 01:19 PM
Posted 27 October 2010 - 06:40 PM
There are no entries in heat treater manuals that will tell you how to harden this steel and temper it. Your methods, temperatures, time at those temperatures, thicknesses of materials, etc all play a role in what you end up with. Because of this, you will have to develop a process that works with what you have made.
To get an idea of what I am talking about, try this experiment:
Take a piece of your laminate bar and a piece of 1095 bar and tack weld them together end to end. Each piece should be about 3" long. (tack welding them together helps insure your control piece (1095) and test piece (laminate) both get the same process done to them)
Harden this piece like you would for 1095. Check both pieces of the bar with a file to make sure both hardened. You will have to be sure you are down to the 1095 on the laminate piece
Start with a low temper temperature like 350 degrees and check each piece with a file or if possible a rockwell hardness tester. (If you use a hardness tester, you will have to remove the SS from both sides of the 1095 to get an accurate test.)
Raise your temper temp and do again.
Repeat the process until your file will start cutting the 1095. The hardness tester will show results right away, but the file method will probably reveal that you can cut the 1095 laminate at a lower temper temp than you can the straight 1095 bar.
While this test may not be ideal, it is a good starting point in helping you understand what is going on with what you have made. Assuming you have a HT method already for 1095, you can take your results from what you know and from the above test and come up with a resonable starting point for your laminate HT.
I hope this all makes some sense.
Posted 28 October 2010 - 01:06 PM
Posted 29 October 2010 - 12:29 PM
I have certainly not done enough experimenting to be able to answer your question, but I will give you a couple of things to think about.
304 has 8% NI where 416 hasn't any Ni and we know what Ni does in relationship to Carbon diffusion.
Do some research on Carbon Diffusion and get a feel for what is happening as the temperature goes up. There is much written on this. See if you can get ahold of John Verhoeven's book Steel Metallurgy for the Non Metallurgist. Check your local library and see if they can get it via Inter Library Loan.