复合实验方法研究温度对管线钢氢脆的影响

Influence of Temperature on Hydrogen Embrittlement of Pipeline Steel by Comprehensive Experimental Method

将慢应变拉伸实验(SSRT)与Devanathan-Stachurski电化学实验相结合,并辅以分子动力学模拟的方法研究了温度对管线钢氢脆的影响,实现了多种实验方法的科学耦合,最终达到预测管线钢氢脆温度阈值的目的。宏观层面,利用SSRT和Devanathan-Stachurski电化学实验方法;微观层面,利用扫描电镜(SEM)观察试样的断口形貌;纳观层面,利用分子动力学模拟方法。结果表明:X90钢氢脆的温度阈值为313K。超过该阈值时,氢脆程度随温度升高而减弱;低于该阈值,氢脆程度随温度升高而增强。得到基于氢扩散动力学的理论模型来预测该临界温度,预测模型与实验结果吻合较好,揭示了氢扩散和积累对裂纹扩展的促进作用,为研究氢致结构材料损伤提供参考。

Slow strain rate test,electrochemical test,and molecular dynamics simulations are combined to study the effect of temperature on hydrogen embrittlement.This new integrated method realizes the scientific coupling of various experimental methods to predict the temperature threshold of hydrogen embrittlement in pipeline steel.At the macro level,slow strain tensile test and Devanathan-Stachurski electrochemical experiment are used;at the micro level,the fracture morphology is observed by scanning electron microscopy(SEM);and at the nano level,the molecular dynamics simulation method is used.The results demonstrate that the temperature threshold of hydrogen embrittlement of X90 steel is 313 K.The hydrogen embrittlement of X90 steel decreases with the increase of temperature when the temperature exceeds the threshold value,and increases with the increase of temperature when the temperature below the threshold.Moreover,the theoretical model based on hydrogen diffusion dynamics is obtained to predict the critical temperature.The predictive model is in good agreement with the experimental results,which reveals the promotion of hydrogen diffusion and accumulation on crack growth and provides a basis for the study of hydrogen-induced structural material damage.