| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method which is applicable to members with various different shapes, hardening conditions, or the like, and can detect a heat treatment abnormality of a steel member to which high frequency hardening is performed without destroying the steel member, and to provide a high performance rolling bearing in which heat treatment quality of a bearing member is assured. <P>SOLUTION: When a smoothing curve satisfies all of the following conditions A-C, it is determined that there is no heat treatment abnormality in a test material. Condition A: the smoothing curve has the maximum peak at a depth position deeper than that of a reflected wave which results from a self-hardened tissue and whose intensity is the lowest, and the intensity of the reflected wave of the maximum peak is the highest except at a part which results from a non-self-hardened tissue and results from surface scattering. Condition B: the intensity of the reflected wave which results from the self-hardened tissue and whose intensity is the lowest is equal to or less than a first predetermined threshold. Condition C: the intensity of the reflected wave whose intensity is the highest is equal to or more than a second predetermined threshold except at a part which results from the non-self-hardened tissue and results from the surface scattering. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
