Improving the corrosion resistance of Inconel 52M laser-cladded steel

Inconel 52M (In52M) laser-cladded steel was analyzed to study the effect of process parameters on the wire deposition mode and the melt pool geometry, which was shown to have a significant effect on the microstructural morphology and the resulting corrosion resistance of the clad. The processing parameters controlled the size and fluid flow in the molten clad pool during clad deposition. The results showed that by decreasing the size of the melt pool during cladding, the growth of coarse Al- and Ti-oxides could be substantially restricted. The presence of these coarse oxides was identified as one of the main causes of poor corrosion resistance in In52M cladded steel. The results showed that by limiting the formation and growth of these oxides, the corrosion resistance of the clads could be drastically improved. The results also showed that the corrosion resistance of In52M clads was not significantly affected by the rate of dilution of the Fe substrate into the clad, which is generally thought to be the most significant factor affecting corrosion performance. This study definitively showed that the corrosion resistance of In52M cladded steel can be considerably improved by adjusting the processing parameters to ensure a relatively small melt pool size during clad deposition, which limits the formation of harmful coarse oxides close to the outer surface of the clad, regardless of the rate of dilution.