| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and a steel product capable of diagnosing accurately the degree of fatigue deterioration of a steel structure caused by a repeating stress and a strain by using a magnetic signal of a measuring object before generation of a visual crack. SOLUTION: In this fatigue life diagnosis method of the steel product, a magnetic head 1 composed of an exciting head 2 and a detection head 3 is arranged on the face having the face accumulation degree on the 111} crystal face of anα-Fe crystal formed on a part of the steel product surface, which is 1.2-1,000 times larger than the face accumulation degree on the 111} face of theα-Fe crystal whose crystal orientation is random, and a.c. energization of the surface is executed by the exciting head 2, and the magnetic signal generated from the surface is measured by the detection head 3, and the degree of a fatigue damage of the steel product is diagnosed by the magnetic signal.
|
