Development of laser cladding stellite F alloy on valve face 2000-05-0113

The laser cladding stellite F alloy on valve face by 2 KW CO₂ laser equipment was investigated. The powder mixture paste was precoated on valve face in experiments of laser cladding process. The laser cladding process, the microstructure of laser cladding layer, the chemical composition distribution and the microhardness distribution in laser cladding layer were examined by metallurgical microscope and scanning electric microscope, and the 1000-hours engine endurance test was conducted in WD615.68 high-performance test engine. The results show that the cladding layer on valve face which possesses fine crystalline grain, close microstructure and low dilutability has been obtained by laser cladding stellite F alloy. The microhardness of the laser cladded layer is above l600 kg/mm², HV_0.2 100 higher than microhardness of bead welding layer at same depth. The operational performances of the laser cladding layer such as wear resistance performance and erosion resistance performance, etc., completely meet the requirements of high-performance engine. The laser cladding process on valve face is potential process in automotive industry.