Wootz Damascus steel blades

Wootz Damascus steel blades contain surface patterns produced by bands of cementite particles which are generated in situ as the blades are forged from small ingots. A process for making these blades has recently been developed which involves making ingots in a gas-fired furnace followed by forging to blade shapes. This study presents a series of additional experiments which provide strong evidence that the mechanism responsible for the formation of the aligned cementite bands is similar to the mechanism that produces banded hypoeutectoid steels. That mechanism attributes the selective formation of ferrite bands to microsegregated alloying elements. The results of this study show that the cementite bands will form in ultraclean hypereutectoid, steels (P and S levels <0.003wt.%) by the addition of small amounts of the carbide-forming elements V, Cr, and Ti at a combined level of <0.02wt%. The results present strong evidence that the cementite bands are formed by a selective coarsening of cementite particles during the thermal cycling of the forging process. The particle coarsening is induced to occur preferentially in the interdendritic regions of the alloys by the very small additions of the carbide-forming elements. (C) Elsevier Science Inc., 1996