CARBON STEEL SHEET HAVING EXCELLENT CARBURIZATION PROPERTIES, AND METHOD FOR PRODUCING SAME

摘要

The present invention, C: 0.20 mass% or more, 0.45 mass% or less, Si: 0.05 mass% or more and 0.8 mass%, Mn: 0.85 mass% or more, 2.0% or less, P: 0.001 mass% or more, 0.04% by weight or less, S: 0.0001 mass% or more, 0.006 or less by mass%, Al: 0.01 mass% or more, than 0.1 mass%, Ti: 0.005 or less mass% or more and 0.3 mass%, B: 0.0005 mass% or more, more than 0.01% by weight and N: 0.001 mass% or more, and 0.01 and containing the following ingredients in mass%, K value of 2.0 or more represented by the 3C + Mn + 0.5Si, and the surface hardness is 77 or less in Rockwell hardness B scale, in the region of the depth from the surface layer 100㎛ less than the average content of N is 100ppm, the carbon potential of the carbon steel sheet which provides not more than 0.6 in the carburizing atmosphere in the carburizing. ;