2002 年 51 巻 12 号 p. 1380-1385
Cyclic softening and hardening behaviors are observed in metallic materials which undergo continuous stress. As a typical example, it is known that a cyclic softening behavior will be accepted in the material strengthened by hot treatment etc. and a cyclic hardening behavior will be accepted in the annealing material.
In this study, we examined the relation formula between the X-ray parameter and the fracture mechanics parameter which undergo variable loading in the SS400 steel as a cyclic hardening material. In addition, we examined the HW685 steel, a cyclic hardening material having the same carbon content in the similar way for comparison.
Furthermore, we summed these data up and examined the relationship between the X-ray parameter and the fracture mechanics parameter when setting the experiment constant value α to 0.12 from the engineering standpoints. As a result, we obtained the significant viewpoints through this study and we will report them.