| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately and efficiently estimate a maximum size in which an aluminum-based inclusion considered to be most harmful as an origin of breakage of a rolling component like a rolling bearing comprising high-strength steel can exist in an arbitrary predictive volume. <P>SOLUTION: Ultrasonic axial loading fatigue testing which applies an axial load causing vibrations at a frequency in an ultrasonic region is applied to a sample piece of high-strength steel. Before the axial load is applied (S3), the sample piece is charged with diffusible hydrogen (S1), and the test piece is left in an atmospheric air at a normal temperature to dissipate the diffusible hydrogen (S2). Subsequently, the sample piece is broken by fatigue by application of the axial load (S3). A size of an aluminum-based inclusion by which breakage has originated is measured (S4), and a maximum size in which the aluminum-based inclusion can exist in an arbitrary predictive volume is estimated by extreme value statistical analysis (S5). <P>COPYRIGHT: (C)2012,JPO&INPIT |
