Skip to content


Please or Register to create posts and topics.

Top of Wootz cake is the spine and the bottom is the cutting edge. 

  1. Roast the wootz cake - Roasting the ingot helps transform the internal microstructure of the steel from a crystalline structure to more of a spheroidized cementite structure. This step is not entirely necessary but unless you do it, the chances of cracking the ingot are much higher and the final type of wootz pattern you will be able to achieve will be different. If you choose to forgo the roast, keep your forging temps extremely high (1100C) and move the metal slowly. Keeping a reduction environment will help to keep material loss to a minimum. 
    1. Method 1: Place wootz cake in a crucible surrounded by iron oxide (Iron oxide keeps the loss of carbon from the wootz cake minimal). Spherical Annealing is done at 1080*C for 4 hours. This also sphereodizes the cementite and breaks up any Widmanstätten pattern cementite
    2. Method 2: Add ingot to kiln and surround with charcoal pieces. Roast at 1080*C for 4 hours. The charcoal creates a reduction atmosphere in the kiln where there is no excess oxygen. (NOTE: This is bad for kiln elements as the oxidation atmosphere creates a protective coating on the kanthol wire.)
    3. If slow cooling happens after solidification your initial microstructure will more likely be that of grain boundary cementite. (Much easier to forge this way as you do not have to break-up the Widmanstätten needles as much. 
    4. This does not destroy the wootz pattern because the as-solidified ingot has considerably larger interdendritic spacing. 
      1. Diffusion times increase as the square of diffusion distance.
      2. Spherodized ingot will have >100 um particle spacing where a forged blade will have between 20-80 um particle spacing
  2. Take ingot out of the kiln after roast and immediately begin Initial forging. By doing this, any microscopic pores inside the metal will be closed up so graphitization does not occur. 
  3. Forge the ingot in the carbon diffusion range which is about 1100C for 1.5% carbon. This helps the cementite dissolve and move around. The dissolution of cementite is an extremely slow process so don't worry about dissolving all of it. This will also help with Ostwald ripening
    1. Forge at an orange heat until about a ½ -1 inch bar is obtained (1100-980C) Once you start losing the orange color, it needs to be heated back up. About 10 Cycles. 
      1. If you forge gently at first and keep the heat range stated above, you will get very minimal cracking.
    2. Grind all scale and any cracks off of the 1 in bar and then forge to desired dimensions. Can test etch at this step as well.
    3. Bring forging temperatures under the Acm temp 950-800 (Forge at a bright red color.)
    4. If you want a spheroidized background instead of a pearlite background, Do the very final forging at temps of 850-700C about 5-10 cycles.
  4. Quenching - Quench in a kiln to get accurate temps. Place the blade on its spine, edge up. This helps to ensure that as much of the edge hardens as possible. With extremely low Mn steel, hardening is much more difficult.
    1. Oil - To austenitize blades, 780 C temperature and 20 minutes of total soaking time. Quench in Parks 50 Oil