杜楠
,
田文明
,
赵晴
,
陈四兵
金属学报
doi:10.3724/SP.J.1037.2012.00005
利用激光电子散斑干涉(ESPI)、电化学噪声(EN)及三维视频显微技术研究304不锈钢在3.5％NaCl溶液中点蚀早期单个蚀孔的发展动力学及其机理.结果表明在0.05V恒电位极化下,点蚀过程可分为4个阶段:首先,电流噪声在740s时发生剧烈波动,钝化膜开始破裂,点蚀孕育期为740s；其次,ESPI图像在750s时产生可见光斑,稳态蚀孔萌生期为10s；再次,750-780s时,蚀孔的发展速率不断增加,表明点蚀处于活性溶解期:最后,蚀孔生长速率迅速下降,发生钝化,而在793s后,由于出现次生蚀孔,生长速率再次上升.使用三维视频显微镜观察蚀孔形貌并测量蚀坑体积的变化,印证了由腐蚀产物浓度分析法得到的单个蚀孔的生长速率,并在蚀坑底部观察到了次生蚀孔.
关键词:
304不锈钢
,
电化学噪声
,
ESPI
,
点蚀速率
Dongqing LI
,
Jun TAO
,
Qingguo Meng
,
Hongyuan FANG
材料科学技术（英）
By means of a newly developed non-contact detecting method, electronic speckle pattern interferometry (ESPI), a method of determining material property data during welding is studied. A TIG fixed-point welding process is modeled in which some achievements of simulation, such as the effect of welding pool on temperature field and nonlinear relation between convection coefficient and temperature, are all considered. In addition, by taking into account effect of heating rate, the workpiece is divided into near-weld zone and far-weld zone, which will be treated with different property values. When the displacement field computed with original property data is compared and matched with the experimental displacement field, which is measured by ESPI, these original data are adjusted properly. A group of raw properties are obtained and are corrected by statistical regression before they enter the simulation process again. By such a loop of “simulation-comparison-modification”, a set of property data that best satisfy the real condition are achieved finally. In such a way, a new method for measuring material properties during welding is found.
关键词:
Material properties
,
null
,
null
,
null
田文明
,
杜楠
,
赵晴
中国腐蚀与防护学报
采用动电位扫描技术测量304不锈钢在3．5％NaCl溶液中不同电位扫描速率下的极化曲线，用电子散斑干涉技术（ESPI）结合动电位扫描测量304不锈钢在不同浓度、温度和pH值的NaCl溶液中的点蚀电位。结果表明，电位扫描速率为0．3—6mV／s时，其对304不锈钢在NaCl溶液中的自腐蚀电位和点蚀电位以及滞后环的大小的影响较小。电子散斑干涉技术测量的点蚀电位表明304不锈钢的点蚀敏感性随着溶液浓度和温度的增加而增大，随着溶液pH值的增加而减小。
关键词:
304不锈钢
,
动电位扫描
,
电子散斑干涉技术
田文明
,
杜楠
,
赵晴
中国腐蚀与防护学报
采用动电位扫描技术测量304不锈钢在3．5％NaCl溶液中不同电位扫描速率下的极化曲线，用电子散斑干涉技术（ESPI）结合动电位扫描测量304不锈钢在不同浓度、温度和pH值的NaCl溶液中的点蚀电位。结果表明，电位扫描速率为0．3—6mV／s时，其对304不锈钢在NaCl溶液中的自腐蚀电位和点蚀电位以及滞后环的大小的影响较小。电子散斑干涉技术测量的点蚀电位表明304不锈钢的点蚀敏感性随着溶液浓度和温度的增加而增大，随着溶液pH值的增加而减小。
关键词:
304不锈钢
,
动电位扫描
,
电子散斑干涉技术
