Patent ID: 11913895
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method for detecting occurrence of a crack or the like, comprising:
a measurement step of, by a current measurement device, measuring a value of a current flowing through a steel material that is applied with tensile stress, the current generated by the steel material being subjected to a hydrogen charging process of immersing the steel material in an aqueous solution and applying a negative potential to the steel material; and
a determination step of, by a device for detecting occurrence of a crack or the like, using the measured current value to determine occurrence of a crack in the steel material when an amount of change in the current flowing through the steel material, a change rate of the amount of change in the current, or a change rate of the change rate of the amount of change in the current exceeds a threshold value,
wherein in the determination step, occurrence of a crack in the steel material is determined when the change rate of the amount of change in the current is less than a negative value of an absolute value of the threshold value, and occurrence of fracture in the steel material is determined when the change rate exceeds the absolute value of the threshold value.