I have been asked continually about "damascus" steel. My answer regarding laminated steel has always been the same. "I won't use it unless I can make it myself." I feel this way because of personal convictions of doing as much of the process as possible myself. I have no problems with knife makers who purchase pre-made damascus billets. Until recently, I have had little experience with forging as I am primarily a stock removal knife maker. I was asked to participate in History channel's show Forged in Fire. In preparation for the show, I practiced with a blacksmith Kyle Lucia with Phoenix Handcraft here in Richmond VA. (See previous blog post) In doing so I quickly became hooked on forging and endeavored to finally make my first laminated steel billet.
I chose 1080 and 15N20 steels to laminate because by my research, this combination is reported to be reliably weldable with good contrast. The contrast is important because if the two steel types do not show up differently after etching (we will get to that part later), the beauty of the laminated steel will not show. After cutting each bar to 6 inch lengths and grinding all surfaces smooth, I welded the corners together as well as a "punty" bar on to serve as a handle.
We then heated up to forging temp in a gas forged turned up to "11" until red hot and then added flux. Flux is an acid that prevents oxidation between the layers that may prevent the steel from welding properly. Once the steel is up to white-hot forging temperature and the flux is bubbling rapidly on the surface of the steel with take it to the power hammer and... BAM!
Once I set the initial weld, we reheat, check the welds on each layer visually and then draw out the billet. Once it is drawn out to about double the length, I allow the billet to cool. Now I can grind the surface free of scale, grind a notch halfway down and fold over with help from a torch. Then its back in the forge for another round of flux and another round of patty-cake.
I started with 14 layers of steel, so in order to get to my desired layer count of 448, I needed to fold the billet 5 times. Once this was accomplished I drew out the billet with the power hammer and then a hand hammer on the anvil to a usable bar of steel. It is always wiser to allow the steel to go through a few normalization cycles before cooling - this removes stress from the steel and smooths the grain structure of the steel. (Yes, steel has grain in its crystal structure) I then cut the bar up for stock removal and surface ground the flats to remove hammer marks and scale.
Once I got the billet back to the knife shop, I took the steel through my normal knife making process. The one addition is that in order for the random laminated pattern to emerge, an etching solution is applied to the steel once polished up to about 800 grit. Depending on the time in solution, the high carbon will darken more or less but the high nickel layers will stay shiny - producing contrast. Then there's nothing left but to put a pretty handle on and sew a sheath! The next billet will be a combination or 1095, 15N20, and 1070.