The Influences of Heat Treatment on the Microstructure and Mechanical Properties of 3.5Ni Steel

摘要

The influence of heat treatment on microstructure and mechanical properties of 3.5Ni steel has been studied in this paper. The experiment results showed that the microstructure and grain of the normalized and tempered steel exhibited a low uniformity, which deteriorated toughness. The grain could be refined after quenching and tempering, and the carbides were recognized dispersing at grain boundaries, the low temperature toughness was improved. After secondary quenched and tempered, the size of grains became smaller, and the low temperature toughness was better.