The Technology Research On Repairing 2Cr13 Vanes Using By Laser Cladding

Turbine blade is one of the core components of the whole steam turbine system.Because the working environment of the blade is vulnerable to water erosion,it is necessary to repair the damaged blade.Cladding layer of Stellite 6 cobalt-based alloy powder on the 2Cr13 substrate by laser cladding technology is a convenient,fast and low-cost method for blade repair.Through the study of cladding process system,it can provide guidance for reasonable formulation of turbine blade repairing process in industrial production.Built a laser coaxial feed additive manufacturing platform.The platform is composed of two parts: manufacturing and testing.The manufacturing part controls the cladding trajectory by controlling the trajectory of the robot's end.The CAD software designs the cladding trajectory.The self-developed program converts the CAD graphic into the ABB robot programming language and simulates the cladding trajectory on the computer.After that,the control robot grips the laser cladding head to complete the laser cladding process.The test part consists of infrared thermometer and acceleration sensor.During the test,the temperature of the cladding metal layer and the running speed of the robot are measured in real time.The effect of laser power,scanning rate and powder feeding rate on the macroscopic morphology of the cladding layer is studied.The results show that the height of the cladding layer increases with the increase of the energy density,and there is a saturation value.The width of the cladding layer increases with the increase of the powder feed rate and the energy density,and does not reach the laser spot diameter.Change again.When the lap ratio is 38%,the surface roughness of the cladding layer is the best.The velocity uniformity of robot affects the thickness uniformity of cladding layer.When the scanning speed exceeds 25mm/s,the height of the cladding layer is easily uneven.A uniform cladding layer can be obtained by making the cladding process in uniform speed region.The microstructure and hardness properties of the cladding layer are tested and analyzed,and different hardness matching can be obtained by controlling the technological conditions.In the multi-channel cladding,the microstructure of the lap area has coarsened,resulting in the decrease of hardness.The microstructure of multilayer cladding specimens has a layer between layers and layers.The multilayer structure consists of remelting heated affected zone,remelting zone and a cladding metal.After the substrate is preheated at 250 C,the macro hardness of the cladding layer can be controlled within the range of 39~41HRC.The micro-hardness of the cladding layer tends to be uniform in the thickness direction.