Protective coating, blast furnace tuyere small sleeve and spraying method of protective coating

The invention relates to the technical field of surface treatment engineering, and discloses a protective coating. The protective coating comprises a primer layer, a transition layer and a surface layer, wherein the primer layer is prepared from nickel base alloy; the surface layer is prepared from yttria stabilized zirconia ceramic; the transition layer comprises 20wt%-80wt% of a primer layer and20wt%-80wt% of a surface layer on the basis of weight percentage of the transition layer. The invention also discloses a spraying method of the protective coating and a blast furnace tuyere small sleeve. The protective coating can be prevented from cracking and peeling easily. 本发明涉及表面处理工程技术领域，公开了一种防护涂层，包括打底层、过渡层和表面层，打底层的成分为镍基合金；表面层的成分包括氧化钇稳定氧化锆陶瓷；过渡层的成分，按过渡层的重量百分比计，包括20~80wt%的打底层的成分和20~80wt%的表面层的成分，还公开了上述防护涂层的喷涂方法和一种高炉风口小套，可以防止防护涂层容易开裂剥落的问题。