热喷涂FeCrAl/WC涂层的组织和高温冲蚀行为

Mierostructure and erosion behavior of thermal sprayed FeCrAi/WC composite coating at elevated temperature

关键词:  热喷涂  FeCrAl/WC涂层  高温冲蚀  攻角

Key words:  thermal spraying  FeCrAI/WC coating  elevated temperature erosion  incidence angle

摘要:

采用粉芯丝材和高速电弧喷涂技术制备高温氧化环境下抗冲蚀磨损FeCrAl/WC涂层。用扫描电子显微镜、能谱仪和X射线衍射仪对FeCrAl/WC涂层的组织、成分和涂层表面冲蚀磨损形貌进行了分析。用自制的高温冲蚀磨损试验机对FeCrAl/WC涂层在不同温度、攻角下的冲蚀磨损性能进行了测试。结果表明,高速电弧喷涂FeCrAl/WC涂层具有颗粒增强复合材料的层状组织特征。450℃以下,FeCrAl/WC涂层均呈现韧性冲蚀行为;90°攻角时不同温度以及650℃时不同攻角对FeCrAl/WC涂层的冲蚀行为影响不大。温度高于350℃,FeCrAl/WC涂层具有良好的全攻角冲蚀磨损抗力,650℃棱角状石英磨粒冲蚀条件下,FeCrAl/WC涂层的冲蚀磨损抗力为20 g钢的1.94~2.03倍。探讨了FeCrAl/WC涂层高温冲蚀磨损机理。

Abstract:

A powder cored wire for FeCrAI/WC composite coating by high velocity arc spray technique was developed.The coating composition,microstructurc and phases were investigated by energy dispersive X-ray spectra,X-ray diffraction and scanning electron microscope.The erosion properties of FeCrA1/WC coating were examined with a self-devel-oped erosion test rig at elevated temperature.The FeCrA1/WC coating exhibits the lamellar characteristic of hard particles reinforced composite material.Erosion-corrosion resistance of FeCrA1/WC coating at elevated temperature is higher than that of 20 g steel.Under oblique impact condition,the relative erosion-corrosion resistance of FeCrA1/WC is 1.94~2.89 times higher than that of 20 g steel at temperature of 650 C.It is found that the FeCrA1/WC coating exhibits typical erosion behavior of ductile materials below 450 C.It seems that test temperatures under incidence angle of 90 and the incidence angles of ere dent at the temperature of 650 C have little effect on the solid particle erosion behavior of Fe-CrA1/WC coating.The erosion-corrosion mechanisms of FeCrAI/WC coatings under elevated temperature were discussed.