不同温度下管线钢氢脆的多尺度综合试验研究

Multi-scale Comprehensive Experiments for Temperature Effects on Hydrogen Embrittlement of Pipeline Steel

针对氢能源管道储运过程中的氢脆问题,设计电化学充氢条件下的X80管线钢临氢行为综合测试试验,实测温度对管线钢氢脆敏感性的影响。结果表明:氢扩散系数和钢内壁氢浓度随着温度的升高而增加;315 K下X80管线钢的断后伸长率及断面收缩率最小,氢脆指数最高;试样断口形貌呈脆性断裂特征。分子动力学模拟结果进一步表明,315 K下裂纹尖端的位错和孪晶释放极少,因此诱发了脆性扩展行为。

Focusing on the hydrogen embrittlement problem in the storage and transportation of hydrogen energy pipelines,a series of experiments are designed to test the macroscopically mechanical behavior of X80 pipeline steel under electrochemical hydrogen charging condition.The results show that the hydrogen diffusion coefficient and subsurface hydrogen concentration in the steel increase as the temperature increases.At a temperature of 315 K,X80 pipeline steel has the lowest elongation to failure and reduction of crosssectional area,and has the highest hydrogen embrittlement index;the fracture morphology exhibits brittle fracture patterns.Molecular dynamics model further reveals that the emission of dislocation and twin from the crack tip is negligible at this temperature,causing brittle crack propagation.