| 摘要 |
PROBLEM TO BE SOLVED: To provide case hardening steel for carburizing or carbo-nitriding capable of obtaining carburized parts excellent in chipping resistance. SOLUTION: In this case hardening steel excellent in chipping resistance shown in the figure, fine TiC is dispersed into steel by the addition of Ti to dispersedly reinforce the matrix of the steel, also, 4Si+Mn+2Cr>4.3 is satisfied to improve its softening resistance, and further, the content of Si is controlled to 0.40 to 1.50% to reduce the depth of an intergranular oxidized layer in the surface layer formed at the time of carburizing or carbo-nitriding compared to that in JIS SCM420 of Si: 0.15 to 0.35%.
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