機械仕上された鋼材の加工変質層の研究 : 第3報, 回転曲げ疲れ強さに及ぼす加工変質層の影響

概要

論文の詳細を見る
When a steel specimen is finished by some mechanical procedures viz. turning, grinding, mechanical polishing etc., the surface of the specimen is coated by an affected layer due to local strain hardening action in these finishing procedures. It is said that the influence of this layer on mechanical strength of a steel specimen is, in often case, not quite negligible. But many questions are still left open yet to be solved with respect to its quantitative consequence. In this study, thickness of this layer and degree of strain hardening in this layer of rotary bending fatigue specimens are decided from distribution of hardness value and X-ray diffraction line width within the surface layer. Local strain hardening in such layer is mitigated by a vacuum low temperature annealing of specimen. By comparison of two kind of endurance limit values obtained before and after vacuum annealing, it has been shown that the rotary bending fatigue strength depends on a hardness of the zone which is extremely near the specimen surface. For some experimental purpose, these results will arouse our caution to the exitence of the "machined surface layer"
一般社団法人日本機械学会の論文
1963-04-25