HIGH-PURITY BEARING STEEL AND METHOD OF SMELTING THE SAME

• Main Authors: TERABATAKE TOMOMICHI, NISHIGUCHI NORITAKA, MATSUOKA KATSUAKI
• Format: Patent
• Language: English
• Published: 11.06.2009
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; METALLURGY OF IRON; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide an inexpensive high-purity bearing steel in which its production cost is almost equal to that of a conventional mass-produced steel and which has less oxide-based non-metallic inclusion, exerts high performance and has high reliability, and to provide a method of smelting the same. SOLUTION: The high-purity bearing steel is characterized in that its sulfur content is ≥0.0020 mass% and the predicted maximum diameter of the oxide-based non-metallic inclusion is ≤15 μm. The method of smelting the high-purity bearing steel includes: decarburizing and refining a preliminarily-desulfurized molten pig iron in a steel converter; tapping the obtained molten steel into a ladle; and refining the resultant molten steel in an RH vacuum degassing device to smelt a bearing steel. In this case, the sulfur content in the molten steel is regulated to be ≥0.0020 mass% before refining in the above RH vacuum degassing device. COPYRIGHT: (C)2009,JPO&INPIT