耐热钢表面激光熔覆Co基合金涂层的高温性能

HIGH TEMPERATURE PERFORMANCE OF A LASER CLAD Co-BASE ALLOY ON STEEL SURFACE

采用高功率CO2激光器在1Cr18Ni9Ti不锈钢表面激光熔覆Co基合金,研究了改性层的组织及在75%Na2SO4+25%NaCl混合盐中的热腐蚀性能.结果表明,Co基合金激光改性层组织细密,其中的Co、Cr元素在涂盐热腐蚀条件下促进了保护性氧化膜CoO、CoO.Cr2O3的形成,显著改善了1Cr18Ni9Ti不锈钢的高温热腐蚀性能.

1 Cr18Ni9Ti stainless steel was clad with Co-based alloy using a high power carbon dioxide laser. The microstructure and hot corrosion properties of the clad layer were investigated. The results show that with an appopriate laser processing, a clad layer may be obtained with very fine microstructure and excellent corrosion resistance. By hot corrosion test with a salt mixture of 75% Na2SO4 ＋ 25% NaCl, the clad can form an oxide scale of fine oxides CoO, CoO·Cr2O3.