Optimization of inconel 625 laser cladding on X65 steel via response surface methodology

To meet the extreme corrosion resistance requirements of deep-sea API 5 L X65 carbon steel pipelines, this study utilizes the Box-Behnken response surface methodology to optimize the laser cladding of Inconel 625. Unlike previous studies focused on single-performance metrics, this research provides a novel coordinated regulation of multi-factor interactions to control interface martensite thickness. By establishing a quadratic regression model (R-squared = 0.9484), we systematically explored the effects of laser power, scanning speed, and powder feeding rate. Results indicate the powder feeding rate most significantly impacts cladding thickness (P < 0.0001), while its interaction with scanning speed (P = 0.0422) is critical for geometric regulation. The optimized parameters-1910 W laser power, 1365 mm/min scanning speed, and 0.47 r/min powder feeding rate-yielded an ideal 1 mm cladding thickness. This precise control window produces refined dendrites and a stable 50-60 μm martensite layer, offering highly reliable process parameters for pipeline remanufacturing.