| 摘要 |
PROBLEM TO BE SOLVED: To provide a nitrided member which is superior in wear resistance and can quickly form a nitrided layer having high adhesion without providing an additional process or facility.SOLUTION: Nitriding treatment is performed on base materials of one of a cradle 9, a piston 6, a retainer 17, and a retainer guide, and of one of a retainer 17 and shoe 7, whose base materials are steel. In those nitrided members in each of which a nitrided layer is formed on the base material, the nitrided layer is composed of a γ'-Fe4 N layer formed on an outermost surface, and a &egr;-Fe3 N layer, formed between the γ'-Fe4 N layer and the base material, in which ranges of nitrogen concentration, hardness, and Young's modulus are between those of the γ'-Fe4 N layer and the base material. |
