摘要
对电化学充氢后的2.25Cr-1Mo钢进行拉伸实验,并在实时拉伸过程中采集声发射信号。结果表明:充氢后2.25Cr-1Mo钢抗拉强度为536.30MPa,下降约57MPa;断面收缩率为43.62%,下降约7%。拉伸断口上出现由氢脆引起的"白点"特征与准解理断裂形貌。充氢后试样拉伸过程弹性阶段的声发射信号活动增强,而屈服阶段的声发射信号活动减弱,变形过程的声发射信号累积绝对能量值要比未充氢试样低约1个数量级。充氢试样拉伸产生的声发射信号比未充氢试样的信号幅值降低约0.33mV,频宽降低0.06MHz。通过对声发射信号的分析发现,充氢试样变形的微观机制为氢促进位错发射与运动,而交叉滑移受到抑制。
Tensile test was conducted on 2.25 Cr-1 Mo steel specimens that were electrochemically hydrogen charged and acoustic emission signals were collected in the real-time stretching process.The results show that tensile strength of 2.25 Cr-1 Mo steel with hydrogen charging is 536.30 MPa,decreased by approximately 57 MPa and reduction of area is 43.62%,decreased by 7%,compared with the specimens without hydrogen charging. Hydrogen embrittlement-induced regions known as＂fisheyes＂and quasi-cleavage morphology are observed on the tensile fracture surface.The AE signals activity in the elastic stage of hydrogen charged 2.25 Cr-1 Mo steel is enhanced,but the acoustic emission signals activity in the yield stage is decreased.The cumulative absolute energy of AE signals of hydrogen charged specimens during deformation is almost one order magnitude lower than that without hydrogen charged specimens.The AE signals amplitude generated by the hydrogen charged specimens is about 0.33 mV lower than that of the specimens without hydrogen charging during tensile deformation,and that the bandwidth of signal is reduced by 0.06 MHz.Though the analysis of AE signals,it is found that tensile deformation microscopic mechanism of hydrogen charged specimens is that dislocation emission and motion is enhanced but dislocation cross-slip is inhibited by hydrogen.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2017年第10期138-144,共7页
Journal of Materials Engineering
基金
国家重点研发计划资助项目(2016YFC0801900)
