CARBURIZED AND QUENCHED MEMBER AND METHOD FOR MANUFACTURE THEREOF

摘要

A method for manufacturing a carburized and quenched member, which comprises using, as a raw material, an alloy steel containing Fe as its main component, 0.10 to 0.50 wt % of C and 0.50 to 1.50 wt % of Si and exhibiting a hardenability (J) of 35 to 50 (at 12.5 mm) as measured by the end quenching test, forming the raw material into a member having a desired shape, subjecting the formed member to a carburization treatment in an anti-oxidation atmosphere to thereby form a carburizized layer, and then subjecting the carburized member to a quenching treatment under conditions wherein the member is monotonously cooled from its pearlite transformation point (A1 point) to its martensite transformation starting point (Ms point) and wherein the degree (H) of rapid cooling in the quenching is 0.01 to 0.08 (cm<-1>); and a carburized and quenched member manufactured by the method. The carburized and quenched member can be enhanced in strength with satisfactory suppression in its quenching strain and with no increase in its production cost.