PRODUCTION OF ULTRACLEANLINESS BEARING STEEL AND ULTRACLEANLINESS BEARING STEEL

摘要

PURPOSE: To obtain an ultracleanliness bearing steel excellent in fatigue properties by using a bearing steel in which the content of Mn is limited as a base metal and regulating the diameter of oxide inclusion grains through electron beam remelting and the subsequent ingot-making operation. ;CONSTITUTION: In this method, a bearing steel in which the content of Mn is limited to ≤0.20% is used as a base metal, and the steel is molten by electron beams, the residence time of the molten metal of the bearing steel in a rectangular platelike container made of copper for water-cooling refining is regulated so as to secure the time required for floating-up and separating oxide nonmetallic inclusions having ≥15μm diameter from the molten metal in the conditions that the dimension of the refining container, the position of baking and the melting speed satisfy the relationship expressed by the formula. Thus, the ultracleanliness bearing steel whose oxide inclusion grains is regulated to ≤15μm diameter can be obtd.;COPYRIGHT: (C)1995,JPO