【作者】 张睿明； 陆晨； 彭文珠； 管俊豪； 马凯； 郑津洋；

【Author】 ZHANG Ruiming;LU Chen;PENG Wenzhu;GUAN Junhao;MA Kai;ZHENG Jinyang;Institute of Advanced Equipment,Zhejiang University;

【机构】 浙江大学特种装备研究所；

【摘要】 加氢站用铬钼钢储氢容器疲劳工况突出,且其材料的氢脆敏感性较高,导致采用断裂力学方法计算获得的疲劳寿命较低。自增强是传统行业提高高压或超高压设备疲劳寿命的常用技术手段之一,然而自增强技术在铬钼钢储氢容器上的应用较少。本文通过开展预应变处理后的4130X钢在100 MPa氢气环境中的慢应变速率拉伸(S SR T)试验,研究了自增强后的残余变形对材料氢脆敏感性的影响。实验结果表明,预应变4130X钢在氢环境下的塑性损减和断裂模式转变与未预应变4130X钢具有相同的趋势。在此基础上,采用断裂力学方法分析了自增强超应变度对铬钼钢储氢容器疲劳寿命的影响,并提出了考虑初始裂纹和反向屈服影响的自增强参数确定方法。结果表明,当初始裂纹位于筒体内壁时,疲劳寿命随超应变度的增加而显著增加;而当初始裂纹位于筒体外壁时,则呈现相反趋势。最佳自增强超应变度的选择,应在满足不发生反向屈服的前提下,使内、外表面裂纹扩展至临界尺寸的循环次数近似相等。更多还原

【Abstract】 The Cr-Mo steel hydrogen storage vessel for hydrogen refueling station has a low fatigue life predicted by fracture mechanics method,due to the material degradation caused by high pressure hydrogen embrittlement.Autofrettage is a common technology to improve the fatigue life of high pressure or ultra-high pressure equipment in traditional industry,however,its application on Cr-Mo steel hydrogen storage vessel has not been studied.In this work,slow strain rate tensile(SSRT) tests for prestrained 4130 X in 100 MPa hydrogen environment were performed to explore the influence of residual deformation produced by autofrettage operation on hydrogen embrittlement susceptibility.The experiment results show that the hydrogen induced plastic loss and fracture mode change of prestrained4130 X has the same trend with that of un-prestrained.Based on these findings,the influence of autofrettage overstrain extent on the fatigue life of Cr-Mo steel hydrogen storage vessel was analyzed by using fracture mechanics method.Furthermore,by considering the effect of initial crack and reverse yielding,the method for autofrettage parameters determination was developed.Results indicate that the fatigue life of vessel significantly increases with the overstrain extent if initial cracks locate at the inner surface of cylinder,while this trend is reversed if initial cracks locate at the outer surface.The optimum overstrain extent can be determined in a way that the lifetime for the inner and outer surface cracks propagating to critical depth are almost equal,while no reverse yielding should occur.更多还原