Steel rings for bearings prodn. - by centrifugal casting with controlled cooling, and heating, followed by rolling to shape

摘要

The prodn. of ring-shaped workpieces of hypereutectoid steel, which after hardening, contains low C martensite with a dislocation substructure, comprises cooling the hollow ingot, or a section of the ingot, obtd. by centrifugal casting, from the casting temp. to is not >100 degrees below the eutectoid transformation, and re-heating the casting to is not >100 degrees C. above the temp. of the eutectoid transformation. After a spheroidal pearlite structure is obtained, the temp. is raised to is not >1150 degrees C, followed by forming a semi-finished product, e.g. by rolling, and finally applying a hardening and annealing treatment. Method utilizes fully the thermal energy supplied by the centrifugal casting of the ring, being sufficient for the subsequent forming and heat treatment, which gives a saving in time.