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

Claim 2:
3. A device for detecting occurrence of a crack or the like, comprising:
an input unit that receives input of a value of a current flowing through a steel material that is applied with tensile stress, the current generated by the steel material being while 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 stores the value into a storage unit; and
a determination unit that reads out the current value from the storage unit, and determines 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 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.