Continuous casting is an efficient route for production of high-quality steel products. However, degradation and failure of caster rolls results in interruptions and thereby limits the mill to achieve its full potential. In this context, top zone caster rolls are subjected to extreme environment including high temperature oxidation, thermal fatigue, stress corrosion cracking, corrosion attack from mold powder containing fluoride, wear, etc. In the present work, a martensitic stainless steel roll was laser cladded with super-martensitic stainless steel. The defect free clad showed a superior hardness, oxidation resistance, high temperature wear resistance compared to the substrate. Based on encouraging results, plant trials were taken with bare and laser cladded caster rolls for a fixed duration. Analysis of bare and cladded rolls after plant trial revealed significantly lower crack density and average depth of crack penetration in the cladded roll compared to the bare roll. This confirmed an enhanced resistance to crack initiation as well as crack propagation in the cladded roll. Further, the mechanism of crack initiation and propagation was determined for both set of rolls. This study can pave way for developing superior laser cladding for enhanced service life of continuous caster rolls and other applications involving extreme environment.

Keywords: Laser cladding; super-martensitic stainless steel; crack initiation; oxidation; wear