The case hardening steel and its production manner which are superior in cold processability, cutting Characteristic and fatigue property after the carburization hardening

摘要

Being the case hardening steel which prevents the generation of the bulky grain of the case hardening steel where cold working, cutting and carburization hardening are administered, is superior in cold processability, cutting Characteristic and fatigue property after the carburization hardening, mass % with, S: 0.001 - 0.15%, Ti: 0.05 - 0.2%, Al: 0.04% or less, N: To restrict 0.0050%, or less the specific range to contain the other specific component, furthermore, Mg: 0.003% or less, Zr: 0.01% or less, Ca: 1 genera or 2 genera or more of 0.005% or less are contained, the precipitation tonnage of AlN is restricted 0.01% or less, circular equivalent diameter 20 millimicrons super, aspect ratio 3 super density d of the sulfide which is (/mm2) with, the content of S [S] (mass %) with, d1700 [S] features that it is satisfied +20. Choice figure Drawing 1