1Cr-1Mo-0.25Vおよび13Cr鋼の中高温疲労き裂伝ぱ特性と酸化層厚さの関係

概要

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Near-threshold fatigue crack properties were investigated for a low-alloy steel, Cr-Mo-V, and a stainless steel, SUS 403, at temperatures ranging from room temperature to 550℃. Fatigue tests were conducted at frequencies of 0.5, 5, 50 Hz under P_<max>-constant, ΔK decreasing conditions to prevent crack closure. The thickness and composition of oxide deposits were evaluated by Auger electron spectroscopy, scanning electron microscopy, and X-ray diffraction techniques. The conclusions can be summarized as in the following. (1) Effective values of the threshold stress intensity range increased with increasing temperature and decreasing frequency for Cr-Mo-V steel, while they were independent both of temperature and frequency for SUS 403 steel. (2) Fatigue crack growth rate was accelerated with increasing temperature and decreasing frequency for Cr-Mo-V steel. The rate is independent of frequency for SUS 403 steel, although acceleration occurred at elevated temperatures. (3) The fatigue threshold and growth properties at elevated temperatures are strongly related to the oxidation process of the bare surface at the crack tip.
一般社団法人日本機械学会の論文
1987-12-25