HIGH-CARBON CHROMIUM BEARING STEEL, AND PROCESS FOR PRODUCTION THEREOF

摘要

A production process comprising heating a material to be treated to a temperature higher than an Ac1 transformation point in a carburizing atmosphere, then slowly cooling the material to a temperature (T) that fulfills formula (1) at a cooling rate of 70°C/Hr or less while keeping the carburizing atmosphere, and subsequently cooling the material in an oxidizing atmosphere: Ar1 - 20 = T (°C) = 300°C ···(1). According to the process, a high-carbon chromium bearing steel in which the depth of a decarburized layer or an overcarburized layer in the surface of the steel material is 0-0.2 mm and which can be cut at low cost and has excellent machinability can be produced with high efficiency using a steel pipe that has been subjected to a hot pipe making procedure.