摘要
利用OM、SEM、EBSD、TEM等手段,分别对热轧态和退火态耐酸管线钢的微观组织、晶界分布、位错及析出相进行表征,测试了不同组织管线钢的氢致开裂(HIC)敏感性,计算分析了有效氢扩散系数、氢陷阱密度及其对不同组织的氢捕获效率,重点探讨了铁素体/珠光体(F/P)界面对耐酸管线钢HIC敏感性的影响。结果表明,随着管线钢珠光体含量的增加,F/Fe 3C界面及F/P界面越多,二者作为不可逆氢陷阱会阻碍氢的扩散,提高氢的捕获效率,有效氢扩散系数降低,管线钢的HIC敏感性提高;F/P界面附近位错的聚集会加速氢原子向高界面能的F/P界面聚集,使氢致裂纹起始于F/P界面处,并沿着F/P界面扩展。
By means of OM,SEM,EBSD,TEM,the microstructure,grain boundary distribution,dislocation and precipitates of hot-rolled and annealed acid-resistant pipeline steel were characterized respectively,the hydrogen-induced cracking(HIC)sensitivity of pipeline steel with different microstructure was tested,and the hydrogen trapping efficiency was investigated by measuring the effective hydrogen diffusivity and hydrogen trapping density.The effects of ferrite/pearlite(F/P)interface on the HIC sensitivity of pipeline steel were discussed accordingly.The results show that with the increase of pearlite content of pipeline steel,more ferrite/Fe 3C interface and ferrite/pearlite interface are observed in the microstructure,which act as the irreversible hydrogen traps and will in turn hinder the diffusion of hydrogen,improve the hydrogen capture efficiency,and reduce the effective hydrogen diffusivity;as a result,the HIC sensitivity of pipeline steel is improved.Moreover,the gathering of dislocations near the F/P interface will accelerate the accumulation of hydrogen atoms near the F/P interface with high interface energy.This will lead to the initiation and propagation of hydrogen-induced crack at the F/P interface.
作者
曹成思
刘静
黄峰
胡骞
王贞
彭志贤
Cao Chengsi;Liu Jing;Huang Feng;Hu Qian;Wang Zhen;Peng Zhixian(State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Engineering Technology Research Center of Marine Materials and Service Safety,Wuhan University of Science and Technology,Wuhan 430081,China)
出处
《武汉科技大学学报》
CAS
北大核心
2020年第4期247-254,共8页
Journal of Wuhan University of Science and Technology
基金
国家自然科学基金资助项目(51871171)
2018年中央引导地方科技发展专项(2018ZYYD026).
