Reasons of Cracking of Erosion-Corrosion Resistant BMS1400 Steel Dredging Pipe

The erosion-corrosion resistant BMS1400 dredging pipe appeared cracking and leakage during service. The reasons for cracking of dredging pipe were analyzed by methods such as macroscopic observation, chemical composition analysis, mechanical performance test, microstructure observation and fracture analysis. The results showed that cracking of BMS1400 dredging steel pipe was stress corrosion cracking caused by the combined action of hydrogen-induced corrosion, processing stress and external force scratching. During the dredging process, pipe body was prone to hydrogen-induced cracking when immersed in seawater. Insufficient bending length, improper pre-bending arc, and insufficient over-bending amount would cause greater stress concentration in pre-bending area. Scratches on the pipe surface during service would cause hydrogen-induced cracks in stress concentration area, which would eventually lead to pipe cracking.