Corrosion Fatigue Failure of a Gray Cast Iron Water Main
Corrosion Fatigue Failure of a Gray Cast Iron Water Main
复制标题
灰铸铁总水管的腐蚀疲劳失效
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
A. Paris
中科院分区：
文献类型：
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作者：
M. Cullin;Todd Petersen;A. Paris
摘要对阿拉斯加安克雷奇一根直径为30.5 cm的灰铸铁水管进行了失效调查，该水管因纵向断裂而失效。附近的压力传感器记录到故障发生时系统压力非常适中，管道没有显示出高级石墨化或重大机械损坏的迹象。对管道材料进行了力学测试和微观分析。确定失效原因为脆性断裂，其始于约40.6 cm长的亚临界腐蚀疲劳（CF）裂纹。腐蚀疲劳裂纹萌生于钢管内壁的铸造缺陷。研究结果表明，亚临界CF裂纹扩展可能对灰铸铁水管造成威胁。灰铸铁中的腐蚀疲劳机制以前没有记录，可能是显示多级失效证据的异常断裂的一个促成因素。
AbstractA failure investigation was conducted on a 30.5-cm diameter gray cast iron water main that failed in Anchorage, Alaska, due to a longitudinal fracture. Nearby pressure transducers recorded very modest system pressures at the time of the failure and the pipe did not show signs of advanced graphitization or significant mechanical damage. Mechanical testing and microanalysis were performed on the pipe material. The cause of the failure was determined to be brittle fracture which initiated at a subcritical corrosion fatigue (CF) crack approximately 40.6 cm in length. The corrosion fatigue crack nucleated from a casting defect on the inside surface of the pipe. The findings of the research reported in this paper suggest that subcritical CF crack growth may be a threat to gray cast iron water pipes. Corrosion fatigue mechanisms in gray cast iron have not been documented previously and may be a contributing factor for anomalous fractures showing evidence of multistage failure.