80kg/mm2高張力鋼の疲労過程における残留応力の挙動

概要

論文の詳細を見る
In this paper, report is made it the pulsating tension tests which were performed by means of a Losenhausen type fatigue machine of the 80kg/mm2 tempered high tensile strength steel. On each of them, two sorts of specimens were tested; the specimens whose surface was smooth, and the specimens with 3mmφ hole (α=2.8). We measured the surface residual stress at N5=105, 2×105, 3×105, 4×105, 5×105, 7.5×105, 106, 2×106, ……, break-down, or 2×105, 4×105, 6×105, 8×105, 106, 2×106, ……, break-down, (where N means the repetition number). To determine the surface residual stress, we used the paralell beam X-ray diffraction method. As the result, on 80kg/mm2 tempered high tensile strength steel, the surface residual stress of the specimen little varied, whether break-down or not. In the case of break-down, the reason why the surface residual stress scarcely varied, is considered as follows; (1) the work hardening coefficient is smaller, (2) carbides configuration and their distribution in steel are different from others, (3) phase difference from other steels (that is, tempered martensites is much more than ferrite.). The half value breadth of the profile became larger in the neighbourhood of the break-down repetition numbers.
社団法人日本材料学会の論文