Precipitation Reactions During the Heat Treatment of Ferritic Steels

摘要

The precipitation reactions in two ferritic steels, 9 Cr-1 Mo-V-Nb and 12 Cr-1 Mo-V-W, were studied. Analytical electron microscopy, optical microscopy, chemical extractions, and hardness measurements were used to determine the types, amounts, and effects of precipitates formed as a function of the heat treatment. The effect of variations in the austenitizing treatment was ascertained. In addition to variations in the austenitizing time and temperature, different cooling rates after austenitization were also used. Air cooling after austenitization (normalization) resulted in little precipitation in both alloys. Precipitation in the 12 Cr-1 Mo-V-W alloy after furnace cooling was found in all cases examined. Under certain conditions precipitation was found after furnace cooling the 9 Cr-1 Mo-V-Nb alloy. (ERA citation 08:002555)