CARBURIZATION SENSING METHOD

摘要

The present invention provides a method for sensing whether carburization occurs or not on an inner surface of a pipe or tube by an electromagnetic testing, comprising: a first step of inserting a carburized tube P0 into an excitation coil 11 and into a detection coil 12, and determining a value of a parameter K; and a second step of setting conditions of the excitation coil so as to obtain the value of the parameter K determined in the first step, and thereafter, inserting a pipe or tube that is an inspection target into the excitation coil 11 and into the detection coil 12 and sensing whether carburization occurs or not on an inner surface of the pipe or tube based on an output signal outputted from the detection coil 12.

主权项

1. A method for sensing whether carburization occurs or not on an inner surface of a pipe or tube by an electromagnetic testing, comprising:
a first step of inserting a carburized pipe or tube in which occurrence of carburization on an inner surface thereof is known into an excitation coil and into a detection coil, and determining a value of a parameter K represented by the following Equation (1):
K=(I·N/L)·F−3/2  (1)so as to sense the carburization that has occurred in the carburized pipe or tube based on an output signal outputted from the detection coil, where a current value of an excitation current passing through the excitation coil is defined as I(A), a length of the excitation coil is defined as L (mm), a number of windings of the excitation coil is defined as N, and a frequency of the excitation current passing through the excitation coil is defined as F (kHz); and
a second step of setting conditions of the excitation coil so as to obtain the value of the parameter K determined in the first step, and thereafter, inserting a pipe or tube that is an inspection target into the excitation coil and into the detection coil and sensing whether carburization occurs or not on an inner surface of the pipe or tube based on an output signal outputted from the detection coil.