[Article 2 (Material Science)]
Detection of Inclusions in Metal Materials Using an Ultrasonic Fatigue Testing System (Page 10-11)
Generally it is known that with most structural metal materials the fatigue strength lowers until a load is applied 106 times, and from 107 times onward the fatigue limit is reached, at which no fatigue fracture will occur. However, it is also revealed that with high-strength metal materials that are hardened or surface treated, internal inclusions become an origin of a fatigue fracture and cause a fracture even at 108 to 109 cycles.
|