Research On Laser Cladding Repair Of Gas Turbine Disk

As a power source for large machinery such as trains,ships,and airplanes,gas turbines can not only ensure the safety of machinery operations,but also save economic costs.At present,there are few gas turbine disks for Inconel625 in China.The laser cladding repair process of this paper,from the perspective of engineering application,for a gas turbine disk with Inconel625 as the base material,from the design of the laser cladding head to the research on the repair process of the gas turbine disk,as well as the actual engineering application,a complete set of The laser cladding repair process suitable for industrial production.The main research contents are as follows:(1)The self-designed laser cladding coaxial powder feeding nozzle head.Due to the laser cladding heads on the market,there are many types of powder feeding devices,and due to the spot diameter,laser focal length and laser focus position of some cladding heads on the market The parameters such as the powder focal length and the position of the powder focal point required in this experiment cannot be matched with each other.It is impossible to perform laser cladding repair on the gas turbine disk with the base material of Inconel625.Therefore,it is necessary to re-apply the outside of the laser cladding head.The additional device and optical path are designed to meet the requirements of the cladding repair of the gas turbine disc of the material.(2)In practical industrial applications,when repairing defects,the height and width of the cladding layer can directly reflect the surface morphology and size of the cladding layer to determine whether it meets the requirements of industrial production.The effect of the height and width of the laser beam is analyzed.The experimental results show that with the increase of laser energy density,that is,the increase of laser power,the height of the cladding layer also gradually increases,but the overall change is not large,because On the one hand,the powder feeding rate is constant,and the amount of powder will not increase.On the other hand,due to the increase in energy density and heat input,the melting amount of the substrate increases,thereby increasing the height of the cladding layer;the width of the cladding layer As the laser energy density increases,the same reason,because the heat input of the substrate is gradually increased,the melting amount of the substrate also gradually increases,thereby increasing the width of the cladding layer.When the laser energy density range is 8.49k J/cm~2?10.62k J/cm~2,that is,the laser power is 600W?750W,the surface shape and size of the cladding layer is the best,which meets the requirements of industrial production.(3)The dilution rate can indicate the degree of metallurgical bonding between the cladding layer and the substrate,and the size of the bonding degree can indicate the effect of laser cladding repair on the cladding layer structure performance,which will directly affect the continued service life of the repaired gas turbine disk.In this paper,the effect of laser energy density on the dilution rate is analyzed.The experiment shows that with the increase of laser energy density,the dilution rate tends to increase.However,if the dilution rate is too large,it may cause pores in the cladding layer.The probability of cracks and other defects becomes larger;too small dilution rate will lead to insufficient metallurgical bonding between the substrate and the cladding layer.In this experiment,when the energy density is 8.49k J/cm~2?10.62k J/cm~2,that is,the laser power is600W?750W The dilution rate is the best,and the quality of the cladding layer is the best at this time,which meets the requirements of industrial production.(4)After meeting the process requirements,it needs to be applied to actual industrial production.This article starts from the actual application,from the gas turbine disk to be repaired to the completion of repair,there is a complete set of operation sequence and operation method:the gas turbine to be repaired first The disc is flaw-detected,then the gas turbine disc to be repaired is visualized to find the defect,then the defect is polished,and finally clamped on the positioner,the cladding path program is written according to the shape of the defect and the defect is repaired To realize the automation of the repair process and improve the repair efficiency.Finally,the metallographic detection of the cladding layer is carried out to check whether the effect of engineering application can be applied to the industrial repair production line.