In order to improve water erosion resistance of low pressure last stage blades of steam turbines

the surface of 1Cr12Ni2-W1Mo1V was hardened by high frequency quenching and the Stellite alloy was surfacing on the base metal. The microstructures and micro-hardness distributions of base metal and two kinds of strengthening layers were studied

and their water corrosion resistance were tested and analyzed. The results show that both high frequency quenching and surfacing stellite alloy can significantly improve the micro-hardness of the working layer. The average hardness of the hardened layer is 413.8 HV

3N

which is 2.03 times of the base metal

while the average hardness of the surfacing layer is 404.4 HV

3N

which is about 2 times of the base metal. Microstructure of strengthening layer is more uniform. The water erosion rates of the two strengthening layers are obviously lower than base metal

which indicates that both methods can effectively improve the water corrosion resistance of the material. Especially after the water corrosion test of the surfacing Stellite alloy layer

there are no obvious water erosion grooves on the surface and no large amount of metal falling off. The mass loss of the surfacing layer is only 1/9 of base metal and 1/5 of the hardened layer. The surfacing layer has better water erosion resistance.