QUENCHING DEPTH MEASURING APPARATUS, QUENCHING DEPTH MEASURING METHOD, SURFACE LAYER DEPTH MEASURING APPARATUS, AND SURFACE LAYER DEPTH MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a quenching depth measuring apparatus and a quenching depth measuring method which are capable of measuring deeper quenching depth highly accurately.;SOLUTION: The quenching depth measuring apparatus 10 according to the present invention comprises: a power source 11 which flows current I to two current probes 22,23 arranged contacting a surface 31 of a steel material 30; a potential difference measurement device 12 which measures a potential difference Vd between two detection probes 24,25 arranged contacting the surface 31 of the steel material 30; and a control section 13 which calculates a quenching depth D of the steel material 30 based on the potential difference Vd between the two detection probes 24,25, which occurs when the current I is allowed to flow between the two current probes 22,23. The control section 13 calculates positions of the two detection probes 24,25 in order to bring a changing rate of the potential difference Vd between the two detection probes 24,25 with respect to a change of the quenching depth in the steel material 30 to the largest in a desired quenching depth D.;COPYRIGHT: (C)2014,JPO&INPIT