Study on Alloy Ductile Iron Air-cooled Roller Repaired by Laser Cladding

The alloy ductile iron air-cooled roller was repaired by laser cladding with self-made Fe-based alloy powder.The microstructure and microhardness were investigated with optical microscope,X-ray diffraction and hardness tester.The results show that the coating repaired by laser cladding takes on the dendric growth,has a metallurgical bonding to substrate,a good profile,no pores and cracks.The phases of coating are composed of the supersaturated martensite and intermetallic Fe3.5B.The average microhardness of coating is 753 HV0.2,which is increased by about 43.7% compared with the air-cooled roller.