Studies of Damascus steel blades: Part 1—Experiments on reconstructed blades

Abstract

In a recent article [J. D. Verhoeven and A. H. Pendray, Mat. Char. 29:195–212 (1992)] the authors demonstrated that the striking pattern on genuine Damascus blades can be reproduced by forging small cruicle solidified steel ingots, but the origin of the cementite particles that form the pattern was not discussed. Experiments are presented here that examine the evolution of the cementite particle formation during the forging process. In addition, a comparison study was done on blades formed from vacuum induction-melted chill cast steels of similar compositions to investigate the role of reduced dendrite spacings. The experiments provide evidence that the cementite particles that produce the bands are formed in the forging process by precipitation from the austenite in planar sheets of cluster particles, with the sheets spaced at a distance corresponding to the primary dendrite spacing inherited from the ingot. The experiments are shown to support the hypothesis that the cluster sheet formation in Damascus steel is a type of carbide banding: The segregated impurity elements of the small ingots are deformed into planar arrays on forging and somehow cause the cementite to nucleate along the planar arrays during the cyclic thermomechanical forging process.