Pb粒子分散ステンレス鋼における高温疲労き裂進展抑止機能

概要

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The arrest function in fatigue crack propagation at 25〜550℃ in air was investigated, using SUS 304 (18 Cr-8 Ni) and SUS 403 (12 Cr) stainless steels containing 0.2 weight percent dispersed lead particles. The P_<max>-constant ΔK-decreasing test, where the minimum load, P_<min>, increased with increasing crack length while the maximum load, P_<max>, remained constant, was employed in order to avoid crack closure. The main conclusions obtained are as follows : (1) Fatigue crack propagation properties including the threshold were independent of the material at room temperature under the closure-free condition. Fatigue threshold values at temperatures higher than the load melting point of 327℃ were about 40% higher for lead-particle-dispersed steels than for host steels. (2) The increase in threshold level at elevated temperatures was explained, considering that the oxide layer spalled at the fatigue crack tip was repaired by the molten lead. Accordingly, we concluded that dispersed lead particles could show the arrest function of the fatigue crack propagation at elevated temperatures.
一般社団法人日本機械学会の論文
1995-01-25