南海海洋大气环境下WC-10Co4Cr涂层初期腐蚀行为研究

Research on the initial corrosion behavior of WC-10Co4Cr coating in the South China Sea marine atmospheric environment

在10Cr13不锈钢表面,采用超音速火焰喷涂(HVOF)技术制备了WC-10Co4Cr涂层。在南海海洋大气环境下,进行户外大气暴露试验。使用腐蚀失重法、拉伸试验、金相、扫描电镜(SEM)等方法对试样的腐蚀形貌、微观组织、力学性能等进行研究。采用电化学测试不锈钢及涂层试样试验前后的电化学特性。结果表明,经过1年大气暴露试验,相比不锈钢裸材,火焰喷涂对不锈钢材料的防护效果明显,金属基体无明显腐蚀,平均腐蚀速率为0.333μm/a,试样强度未发生明显改变。试样中间区域喷涂层完好,腐蚀电流密度较暴露前几乎没有变化。

On the surface of 10Cr13 steel,WC-10Co4Cr coating is prepared by high velocity oxygen fuel(HVOF)technology.The outdoor atmospheric exposure test is carried out in the marine atmospheric environment of the South China Sea.The corrosion morphology,microstructure and mechanical properties of the samples are studied by corrosion weight loss method,tensile test,metallography,scanning electron microscope(SEM)and other methods.Electrochemical properties of stainless steel and coated samples before and after the test are measured by electrochemical tests.The results show that after 1 year of atmospheric exposure test,compared with bare stainless steel,flame spraying has obvious protective effect on stainless steel material,and the metal matrix has no obvious corrosion,and the average corrosion rate is 0.333μm/a,the strength of the samples does not change significantly.The spray coating in the middle area of the sample is intact,and the corrosion current density has almost no change compared with that before exposure.