| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for manufacturing carburized steel parts such as a gear, a shaft and a bearing for an automobile etc. and excellent in indentation resistance and in-core-part toughness by rendering the crystal grain in steel material ultrafinine to remove the surface defect thereof. <P>SOLUTION: The steel material including by mass% 0.10-0.30% C, 0.05-2.00% Si, 0.10-2.00% Mn,≤0.030% P,≤0.030% S,≤5.0% Ni,≤6.0% Cr,≤2.0% Mo, 0.005-0.05% Al,≤0.0100% N and further one or both of 0.05-0.20% Ti and 0.02-0.20% Nb and the balance Fe with inevitable impurities, is formed into the shape of the parts, and is subjected to carburizing and hardening, and further subjected to repeated hardening of normal hardening or induction hardening, so that prior austenite crystal grain diameter is made fine in accordance with No.11 or higher of JIS G0551 and after tempering the steel material, and the surface is ground to obtain the carburized parts excellent in the indentation-resistance. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
