Experimental study on high-cycle fatigue performance of laser cladding additively manufactured 316L stainless steel

Laser cladding (LC) technology has garnered significant attention for its application in the repair of corrosion damage in steel structures. However, research on the high-cycle fatigue performance of LC materials remains limited. This study employed 316L stainless steel powder to produce LC specimens and conducted uniaxial tensile-tensile high-cycle fatigue tests to explore various laser deposition directions and surface roughnesses. The resulting S-N curves provide insights into the high-cycle fatigue behaviour of LC materials. Additionally, SEM images were utilized to analyse the fatigue failure fracture characteristics. The experimental results reveal that cladding materials deposited parallel to the loading direction exhibit superior high-cycle fatigue performance. Fatigue fractures in the specimens generally originate from laser fusion defects, which not only reduce the lifespan of the specimen but also influence the failure location. Fatigue failure assessments of the lasercladded materials were conducted via equivalent life diagrams, which revealed a high degree of correlation with the actual failure conditions. Existing fatigue design curves for base materials can be applied to the highcycle fatigue performance design of laser-cladded 316L stainless steel, demonstrating a performance that surpasses the average level of steel butt welds.