SENSITIZATION OF TYPE-430 FERRITIC STAINLESS-STEEL DURING CONTINUOUS ANNEALING

The possibility that type 430 stainless steel can become sensitized du ring annealing after hot-rolling was studied by simulated cycles of co ntinuous-annealing heat treatments, and by calculation of the carbon s olubility, It was found that the lower-carbon steel could be sensitize d at lower annealing temperatures than the higher-carbon steel, which is in line with plant experience. The difference in sensitization beha viour is ascribed to the lower rate of recovery of the lower-carbon st eel during cooling, since recovery is sensitive to the grain size, At practical heat-treatment temperatures, austenite formation does not pl ay a role.