| 摘要 |
PROBLEM TO BE SOLVED: To prevent partial tempering or a quenching crack to be caused by repeated surface quenching from occurring when quenching a surface of a steel component using a moving quenching method.SOLUTION: A steel component 10 is constituted of a carbon steel S45C by JIS designation and includes an annular hole having an inner circumferential face serving as a mold releasing face. A quenched surface layer is formed on the whole circumference of the inner circumferential face to impart abrasion resistance, durability or the like thereto, The quenched surface layer includes a primary quenched part 12 and a secondary quenched part 20. The primary quenched part 12 is a part of the inner circumferential face of the steel component 10, on which surface quenching is applied over a range of approximately 360° along the &thetas; direction. A soft zone 14 is a zone where the primary quenched part 12 is not formed. The secondary quenched part 20 having a quenched depth smaller than that of the primary quenched part 12 is formed on the soft zone 14. |
