伸線強加工高強度鋼における非拡散性水素吸蔵による疲労強度低下と低温焼鈍しの関係

概要

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This paper discusses the influence of irreversible hydrogen and low temperature annealing on the fatigue strength in a cold drawn high strength steel. Fatigue tests were conducted for as-received and annealed samples. Samples were cathodically hydrogen charged, and internal hydrogen states were changed as follows: (a) virgin sample and (b) the sample that contained only irreversible hydrogen. In the case of an as-received sample, irreversible hydrogen did not influence the. fatigue strength. However, the fatigue strength of an annealed sample was decreased by irreversible hydrogen. The activation energy which irreversible hydrogen requires to desorb from its trap site was unchanged by low temperature annealing. Slow strain rate tensile tests showed that the sensitivity to hydrogen embrittlement was increased by low temperature annealing. In the annealed sample, the fine carbide precipitates in ferrite lamella, which was observed by transmission electron microscope, were considered to induce sensitivity to hydrogen embrittlement, and thereby caused a decrease in the fatigue strength of the annealed sample by irreversible hydrogen.
社団法人日本機械学会の論文
2009-02-25