DILUTION RATE ANALYSIS OF REPAIRING 316L STAINLESS STEEL PUMP IMPELLER BY LASER CLADDING INCONEL 625 POWDER

In the oil and gas industry, critical rotating equipment reliable performance is crucial in the seamless operation of production and processing facilities. This paper uses a pump impeller as the basis for a deep dive into novel repair methods. The impeller retained excessive damage to the wear ring landing area while the wall thickness of the damaged location was critically reduced, making it hard to repair using conventional methods or welding techniques. It is observed that the traditional welding techniques, due to excessive heat, could lead to deformation leading to potential challenges in assembling the pump rotor. Laser cladding (LC) provides distinct advantages for precision control over the heat input, reducing the deformation and cooling time required. LC technology was crucial to the current study because it caters for intricate, complex geometries and sizes, which is impossible with conventional technologies. The process parameters such as laser power, traverse speed and powder feed rate enable tailored repairs that could mitigate deformation and preserve the mechanical properties of the base metal. The use of Inconel 625 powder with SS 316 base metal is well known to provide superior corrosion resistance and enhanced mechanical properties. While the capability of the technology and powder is well charted, its specific application in pump repairs needs further research and development. This research takes an experimental approach, focusing on understanding the effect of the process parameters on the base metal from a microstructure point of view. A series of 27 samples were analyzed under microstructural analysis, which helps to decipher the impact of variations in the laser power, powder feed rate, and cladding speed. The study calculates the dilution rate to identify the optimum parameters for repairing the damaged impeller.