摘要
设计位移控制的拉伸试验,使用磁通门传感器监测拉伸过程中的磁信号,采用扫描电镜、X射线衍射仪、MPMS磁学测量系统和透射电镜等方法观察拉伸过程中微观组织的演变规律。重复性试验和磁化试验的结果说明了监测磁信号的可靠性。拉伸过程的磁信号可分为3个阶段,第1阶段磁信号快速增加、增加速度变缓,第2阶段磁信号持续增加、增加速度变快,第3阶段磁信号呈现上下起伏的振荡现象。第1和第2阶段的α′-马氏体相对含量分别变化了0.4%和5.8%,第3阶段试样的位错密度相较第1阶段更大。3个拉伸阶段磁信号变化的机理分别为,第1和第2阶段是马氏体相变和应力磁化α′-马氏体的共同作用,第3阶段与位错的作用有关;应力与磁信号之间存在相关性,可通过监测304不锈钢的磁信号振荡现象来对塑性变形失效进行预警。
The displacement-controlled stretching test was designed to monitor the magnetic signal during the stretching process using fluxgate sensor,and the microstructure evolution during the stretching process was observed using scanning electron microscopy(SEM),X-ray diffractometer(XRD),MPMS magnetic measurement system and transmission electron microscopy(TEM).The results of the repeatability test and magnetization test illustrate the reliability of monitoring the magnetic signal.The magnetic signal of the stretching process can be divided into three stages.The magnetic signal increases rapidly and the increase slows down in the first stage,the magnetic signal increases continuously and the increase becomes faster in the second stage,the magnetic signal shows an oscillation phenomenon of up and down in the third stage.The relative content ofα[DK]′-martensite in the first and the second stages changes by 0.4%and 5.8%,respectively,and the dislocation density of the specimens in the third stage is greater than that in the first stage.The mechanisms of magnetic signal change in the three stretching stages are the combined effect of martensite phase transformation and stress magnetization ofα[DK]′-martensite in the first and the second stages,and the third stage is related to the effect of dislocations.There is a correlation between stress and magnetic signal,and the phenomenon of magnetic signal oscillation of 304 stainless steel can be monitored to provide early warning of plastic deformation failure.
作者
蓝希旺
胡博
石文泽
任尚坤
罗炜韬
程虹之
陈宇
LAN Xi-wang;HU Bo;SHI Wen-ze;REN Shang-kun;LUO Wei-tao;CHENG Hong-zhi;CHEN Yu(Key Laboratory of Nondestructive Testing of Ministry of Education,Nanchang Hangkong University,Nanchang 330063,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2023年第3期123-130,共8页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51967014)
江西省主要学科学术和技术带头人培养计划——青年人才项目(20204BCJ23001)。
关键词
304奥氏体不锈钢
塑性变形
磁监测法
损伤监测
马氏体相变
304 austenitic stainless steel
plastic deformation
magnetic monitoring method
damage monitoring
martensitic phase transformation
