Patent ID: 9304108
Filing Date: 2016-04-05
CPC Classification: G01N

Claim Text:
1. A quenching depth measurement method of measuring quenching depth in a workpiece, the method including: magnetizing the workpiece by arranging a magnetizer including an excitation coil near the workpiece; detecting an induction magnetic field generated by the magnetization by a detection coil to measure an output voltage of the detection coil; and determining a thickness of a quench hardened layer of the workpiece based on: known electromagnetic characteristic information on an unquenched material not subjected to quenching and made of a workpiece equivalent material; known electromagnetic characteristic information on a completely quenched material subjected to quenching and made of the workpiece equivalent material; and an output voltage value measured by the detection coil, wherein: the electromagnetic characteristic information includes an estimated output voltage value of the detection coil obtained by analysis based on a finite element method using initial magnetization curves and electric conductivities of the unquenched material made of a workplace equivalent material, and initial magnetization and electric conductivities of the completely quenched material made of a workpiece equivalent material.