Patent ID: 6197128
Filing Date: 2001-03-06
Classification: C21D,C22C,F16C,Y10S

Abstract:
A rolling bearing comprising a rolling bearing ring having a mill scale surface and a rolling element, said rolling bearing ring and said rolling element each having a surface portion and a core portion, said rolling element in contact with said rolling bearing ring, wherein the portion of said rolling bearing ring in contact with said rolling element forms a rolling contract surface, wherein at least one of said rolling bearing ring and said rolling element consists of carburized steel consisting essentially of at least 0.3 wt. % and at most 0.6 wt. % of C, at least 0.1 wt. % and at most 0.35 wt. % of Si, at least 1.1 wt. % and at most 1.5 wt. % of Mn, at least 0.5 wt. % and at most 2.0 wt. % of Cr, at least 0.2 wt. % and at most 0.6 wt. % of Ni, and at least 0.15 wt. % and at most 0.5 wt. % Mo, and wherein said carburized steel has a distribution of carbide having a maximum size of at most 3.5 .mu.m below said rolling contact surface and having a maximum size of at most 8 .mu.m below said mill scale surface and wherein said carburized steel includes at least 20% and at the most 30% of retained austenite in said surface portion and at most 5% of retained austenite in said core portion.