GAS-CARBURIZED STEEL COMPONENT WITH EXCELLENT SURFACE FATIGUE STRENGTH, GAS-CARBURIZING STEEL MATERIAL, AND PROCESS FOR PRODUCING GAS-CARBURIZED STEEL COMPONENT

摘要

is used in the manufacture of gas carburizing steels for carburizing steel components , mass % in the composition of the base material , C: 0.1 to 0.4%, Si: 1.2 to greater than 4.0%, Mn: 0.2 to 3.0%, Cr: 0.5 to 5.0%, Al: 0.005 to 0.1%, S: 0.001 to 0.3%, N: 0.003 to 0.03% containing and , O: 0.0050% or less, P: is limited to not more than 0.025% , the content of the addition, Si, Mn and Cr ( mass %) of the [Si%], [Mn%], the following equation when a [Cr%] (1) a satisfactory and , to a range of 2 to depth from the surface to 50 formula (2) for gas carburizing steels there is a lack alloy layer satisfying . 32 3.5 [Si%] + [Mn%] + 3 [Cr%] & 9 ... (1) 3.5 [Si%] + [Mn%] + 3 [Cr%] 9 ... (2) ;