锡黄铜在3.5%NaCl中的液固两相流冲蚀机理研究

利用旋转式冲蚀磨损试验机,对锡黄铜在3.5%NaCl溶液中进行液固两相流冲蚀磨损试验,利用扫描电镜详细分析了不同条件下锡黄铜表面的微观形貌、失效规律及微观破坏机理.结果表明:锡黄铜在失重的不同阶段对应不同的磨损机制,在不同外界条件下其破坏机制也不尽相同.锡黄铜在阴极保护即无腐蚀影响下,试样发生严重冲蚀前存在门槛速度,冲蚀形貌主要以犁削和铲削为主同时兼有切片.当冲蚀速率增加,冲蚀切削形貌减少,而冲蚀时间的增加将导致冲蚀率首先增加后减小并趋于平衡;在无阴极保护作用下,试样表面出现腐蚀凹坑,冲蚀率大幅度增加,随着冲蚀速率的增加失重率增加,但随冲蚀时间增加,冲蚀率减小.

Investigation of Erosion Mechanism of Tin Brass in 3.5% NaCl Liquid-Solid Two Phase Flow

Erosion-wear of tin brass in liquid-solid two-phase flow (3.5% NaCl+SiC) was investigated by using a rotating disk system. Results show that the tin brass in different stages presented different wear mechanisms, and its failure mechanisms under different environmental conditions were different. Under the athodic protection, serious erosion of tin brass are observed after a threshold velocity, plough sharpen and shovels cut were the mainly erosion morphology. However, shovels cut were reduced when the velocity increased. By increasing erosion time erosion rate first increased then decreased and then tended to balance. Without cathodic protection, corrosion pits were observed on the sample surface, the erosion rate increased significantly in comparison with the samples under the cathodic protection, mass loss rate increased with the increase of velocity, but erosion rate decreased with the increase of erosion time.