摘要
采用电化学充氢方法研究了氢对铁素体/贝氏体双相X70管线钢拉伸和疲劳性能的影响;采用扫描电镜(SEM)和电子背散射(EBSD)技术观察了拉伸和疲劳断口的形貌及疲劳断口处的组织。结果表明:氢对双相X70管线钢的强度影响不大,但显著降低钢的塑性,特别是断后伸长率;充氢后拉伸断口由塑性的韧窝断裂转变为脆性准解理断裂;氢显著加速钢疲劳裂纹萌生和裂纹扩展速率,降低疲劳寿命;氢加速位错等缺陷在晶界及铁素体/贝氏体界面处的聚集,导致断裂模式发生变化,从而降低钢的塑性和疲劳寿命。
Effect of hydrogen on tensile and fatigue properties of ferrite/bainite dual-phase X70 pipeline steel was studied by electrochemical hydrogen charging method.The morphology of tensile and fatigue fracture surfaces and microstructure near the fatigue fracture surface were observed by means of scanning electron microscopy(SEM)and electron backscatter diffraction(EBSD)technique.The results show that the hydrogen has little effect on the strength of the dual-phase X70 pipeline steel,but significantly reduces its plasticity,especially the elongation.After hydrogen charging,the tensile fracture changes from plastic dimple fracture to brittle quasicleavage fracture.Hydrogen significantly accelerates the initiation and propagation rate of fatigue cracks in the steel,reducing fatigue life.Hydrogen accelerates the aggregation of dislocations and other defects at grain boundaries and ferrite/bainite interfaces,which leads to the change of fracture mode,thus reducing the plastic and fatigue life of the steel.
作者
吴英铜
乔桂英
徐凯
肖福仁
WU Ying-tong;QIAO Gui-ying;XU Kai;XIAO Fu-ren(Key Laboratory of Deep Remediation of Heavy Metals in Water and Resource Utilization of Hebei Province,School of Environment and Chemical Engineering,Yanshan University,Qinhuangdao 066004,China;Key Laboratory of Metastable Materials Science&Technology and Hebei Key Laboratory for Optimizing metal Product Technology and Performance,College of Materials Science&Engineering,Yanshan University,Qinhuangdao 066004,China)
出处
《材料热处理学报》
CAS
CSCD
北大核心
2023年第9期114-121,共8页
Transactions of Materials and Heat Treatment
基金
河北省自然科学基金-先进钢铁联合基金(E2021203069)
河北省自然科学基金-青年科学基金(E2022203174)
河北省重点研发计划项目(22314601D)
河北省创新能力提升计划项目(22567609H)。
关键词
管线钢
氢脆
疲劳
塑性
pipeline steel
hydrogen embrittlement
fatigue
plasticity
