PROCESS FOR THE IMPROVED HEAT TREATMENT OF STEELS USING DIRECT ELECTRICAL RESISTANCE HEATING

摘要

PROCESS FOR THE IMPROVED HEAT TREATMENT OF STEELSUSING DIRECT ELECTRICAL RESISTANCE HEATINGABSTRACT OF THE DISCLOSUREA process for the energy efficient heat treatmentof steels wherein a steel workpiece is rapidly heated to atemperature above the A3 temperature of the steel to convertthe steel to austenite, the workpiece is then rapidly quenchedin a liquid quench medium to convert the austenite to apredominantly martensitic microstructure, and the steel isthen tempered by rapid heating while the workpiece is undertension, the tempering serving to convert the steel to atempered martensitic form. The present invention virtuallyeliminates the problem of quench cracking and minimizesquench distortion as well as providing a finished productwith improved uniformity, improved surface quality, andimproved mechanical properties.