Microstructure and Corrosion Behavior of Ni-Cr-Mo Nickel-based Alloy Weld

Abstract

The mechanical properties and corrosion performance of the N10276 alloy welded joint were investigated with nano-hardness testing and electrochemical measurement. The results showed that solidification mode changes from equiaxed crystal to columnar crystal from the center of the weldment to the fusion zone. With the increase of immersion times, the diameter of capacitance arc and the impedance modulus increase, and the corrosion resistance of HAZ decreases. The strengthening effect of welded metal was more obvious than that of heat affected zone for the nickel-based welded joint and especially in coarse grained heat affected zone, the hardening resulted from overheating was not apparent. Nickel-based weld metal with high content of alloying elements were often segregated at interdendritic regions or precipitated in grain interior under nonequilibrium solidification, which differ from conventional low alloy steel welded joint.