炭素鋼,ステンレス鋼の液体衝撃エロージョンの流速依存性

抄録

Liquid impingement erosion is an important issue for the pipe wall thinning due to the ageing of power plant. In this study, liquid impingement erosion tests were carried out on the pipe steels using the test chamber specified in the ASTM G134 standard. It was found that erosion rate increases with the 6th power of impact velocity for S15C and STPA24, and the 7th power for SUS304, and the threshold velocity below which erosion rate is negligible small was found 80m/s for S15C, 90m/s for STPA24 and 120m/s for SUS304. It was clarified that the erosion mechanism by liquid impingement proceeds due to fatigue. That is, asperities appear by plastic deformation at the crystal grain boundaries and the asperities produce high stress concentrations, resulting fatigue crack initiation and material removal.