Carbide Dispersion Carburizing of a 12% Chromium Steel

Abstract

Carburizing of a 12%Cr steel containing 0.1–0.9%Si was performed at 950°C, and the microstructure, the hardness and the wear resistance of the carburized and hardened layer were examined. Addition of Si was effective to eliminate the formation of massive carbides in the outer region and also of boundary carbides in the intermediate region. It was revealed that fine dispersion of Cr₇C₃ carbides occurred throughout the carburized layer. The radius and amount of the carbides in the surface region were about 0.25 μm and 30% by volume, respectively. The carburized and hardened layer with such fine dispersion of Cr₇C₃ was much superior in the hardness as well as the wear resistance to the ordinary high chromium tool steel.