| 摘要 |
PROBLEM TO BE SOLVED: To provide a roll bearing which is hardly worn or damaged and whose service life is long in addition to a structure change to a white structure hardly occurs even when used in a hydrogen atmosphere. SOLUTION: An inner ring 1 and an outer ring 2 of a deep groove ball bearing is made up of alloy steel containing carbon of 0.5 mass% to 0.9 mass%, silicon of 0.6 mass% to 1 mass%, manganese of 0.6 mass% to 1.2 mass%, chromium of 6.5 mass% to 9.5 mass%, and molybdenum of 1 mass% or lower and whose remaining part is iron and unavoidable impurity. A resistance value of the structure change is 10 or more. Furthermore, hardening and tempering are performed. The residual austenite amounts of track surfaces 1a and 2a are 10 vol.% to 20 vol.% and hardness is Hv674 to 772. The old austenite grain size is 7 to 10 in the grain size number. COPYRIGHT: (C)2011,JPO&INPIT |
