High-temperature wear resistance of Co-based cladding layers by ultra-high speed laser cladding on the surface of the cast-rolling roller sleeve

In order to improve the service life of the cast-rolling roller sleeve, a Co-based cladding layer was prepared on the surface of the 32Cr3Mo1V cast-rolling roller sleeve using ultra-high-speed laser cladding technology. The surface morphology, microstructure, high-temperature friction and wear properties of the cladding layer were analyzed. And which was compared with that of the preferred conventional laser cladding layer. The results show that the preferred ultra-high-speed and conventional laser cladding layers all have a smooth surface and a good combination with the substrate without obvious cracks, pores and other defects. In contrast, the microstructure of the layer by ultra-high-speed laser cladding is very uniform and fine. And the dendrite axis spacing is extremely small, which largely suppresses the range of dendrite segregation. As a result, the more uniform distribution of element was obtained. During the process of 700 ℃ high temperature friction and wear test, the super oxide wear debris produced from the high-speed laser cladding layer is more smaller compared with that of conventional laser cladding layer. Therefore the agglomeration effect is more likely to occur, which is conducive to the formation of the enamel layer with anti-friction resistance. As the same time, the deformation of the layer by ultra-high-speed laser cladding is smaller, which has more effectively support for the enamel layer, consequently a large area enamel layer can be obtained. Thus the ultra-high-speed laser cladding layer exhibits excellent high-temperature friction and wear resistance.