Carburized boron steels for gears
AssigneeSamsung Heavy Industries Co., Ltd.
InventorsIn-seok Yu, Yong-gueon Ji, Gang-hyeong Kim
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Abstract
A boron steel consisting of 0.18% to 0.35% C, 0.06% to 0.15%, Si, 0.50% to 1.00% Mn, 0.40% to 0.90% Cr, 0.01% to 0.05%, Al, 0.01% to 0.04% Ti, no more than 0.012% N, no more than 0.003% O, 0.0005% to 0.0030% B, and the balance Fe and impurities contained inevitably in manufacturing the steel, all percentages being based on the weight of the steel. The ratio of Ti to N is 3.4 to 6.0. The boron steel has an improvement in the reduction of heat-treatment distortion, surface oxidation in carburization and material cost, and also has superior hardenability, mechanical strength and fatigue strength.
Claims2
A carburized steel consisting of 0.18% to 0.35% C, 0.06% to 0.10% Si, 0.50% to 1.00% Mn, 0.40% to 0.90% Cr, said Si, Mn and Cr reducing surface oxidation on said steel to a layer less than 10 .mu.m thickness, 0.01% to 0.05% Al, 0.01% to 0.04% Ti, no more than 0.12% N, no more than 0.003% O, 0.0005% to 0.0030% B, and the balance Fe and impurities contained inevitably in manufacturing the steel, the ratio of Ti to N being 3.4 to 6.0, and all percentages being based on the weight of the steel.
Dependencies are inferred from the claim text.