A New Method for Making Crucible Damascus Steel Blades

Crucible Damascus blades are hypereutectoid steels forged from small ingots. In the past, the crucibles have always been tightly sealed and the surface patterns on the blades resulted from a banded cementite/pearlite microstructure. This work shows that, firstly, the blades may be made using crucibles open to the air. Secondly, blades can also be made with the same type of surface patterns as on traditional crucible Damascus blades, but instead of the patterns being produced by a banded cementite/pearlite microstructure they are produced by a banded cementite/spheroidite microstructure. The spheroidite structure is an array of fine spherical carbides in a ferrite matrix produced by the divorced eutectoid transformation. Finally, the study adds support to experiments showing that the formation of the sheets of aligned cementite particles during forging, that in turn produce the banded microstructure, requires the presence of low amounts of carbide forming elements, notable V and Cr.