耐磨蚀BMS1400钢疏浚管开裂的原因

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

耐磨蚀BMS1400疏浚管在服役过程中出现开裂渗漏,通过宏观观察、化学成分分析、力学性能试验、显微组织观察和断口分析等方法,分析了疏浚管开裂的原因。结果表明:BMS1400疏浚钢管的开裂是在氢致腐蚀、加工应力以及外力划伤等多因素综合作用下导致的应力腐蚀开裂;疏浚过程中,管体浸泡在海水中易发生氢致开裂,钢板预弯长度不足、预弯弧度不当及过弯量不足均会使预弯区域产生较大的应力集中,服役过程中管体表面划伤使应力集中域产生氢致裂纹,最终导致管道发生开裂。

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.