CRYSTALLOGRAPHY AND MORPHOLGY OF CEMENTITE PRECIPITATES FORMED DURING RAPID SOLIDIFICATION OF A FERRITIC STAINLESS STEEL

摘要

A wedge-formed sample has been prepared for a low carbon Fe-12Cr based alloy by casting the base material into a wedge copper mould in a vacuum induction furnace. Cooling rates through the solidifi- cation temperature range were measured to be in the range from 3.7×10~3 to 10~5 K s~-1 within the tip region of the wedge-formed sample(12 mm from the tip). Microstructural observations showed that a high density of carbide precipitates are formed in the delta ferrite grains within, and only within, this region.