人工海水中における高張力綱溶接材の腐食疲労き裂進展特性

概要

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Corrosion-fatigue (CF) crack growth behavior of two high-tensile strength steel weldments, HT 50-TMCP and HT 80, have been investigated in ASTM synthetic seawater under free corrosion and a cathodic potential. Tests were conducted using sinusoidal loads at a frequency of 0.17 Hz and a load ratio of 0.1. The CF crack growth rates of the weldments in terms of the stress intensity factor range ΔK were considerably lower than those of the base matals, since the crack opening loads were increased by the compressive residual stress by welding, corrosion products, and calcareous deposits. The CF crack growth rate of the weldments agreed with those of base metal in terms of a modified effective stress intensity factor range ΔK_<cont> compared in the same environment. In the free-corrosion potential, effects of residual stress on the CF crack growth of the HT 50-TMCP weldment were scarcely observed because the crack growth was accelerated by dissolution, whereas that of the HT 80 weldment was almost the same as that in air. The cathodic protection of the weldment became effective at low ΔK_<cont> levels, while the crack growth rates at high ΔK_<cont> levels were much accelerated due to hydrogen embrittlement.
社団法人日本機械学会の論文
1989-02-25