Study on the High Temperature Tensile Properties and Strengthening Mechanism of Nitrogen Containing Nickel‐Based Deposited Metals

Abstract

This article investigates the tensile properties and strengthening mechanism of nitrogen‐containing nickel‐based flux cored welding wire deposited metal from room temperature to 900 °C. The results showed that the high‐temperature strength of the deposited metal increased with the addition of Tungsten and Nitrogen. When the temperature reaches 700 °C, M23C6 carbides begin to decompose. The alloying elements dissolve back into the matrix, and the solid solution strengthening effect minimizes the plasticity of the alloy. More carbonitrides are precipitated within the crystal with temperature. During high‐temperature deformation, carbonitrides fractures at the interface with the substrate due to difficulty in coordinating deformation. Therefore, the crack source formed greatly reduces the strength of the material. In addition, the stacking faults present in the low‐temperature zone have a significant impact on the work hardening of materials. The main deformation mechanism is the unit dislocation a/2 < 110> cutting precipitation phase. It can be observed that the dislocation cutting precipitation mechanism system has transformed into a dislocation bypassing precipitation mechanism system at intermediate. Finally, the anomalous yield strength (YS) and intermediate temperature brittleness phenomenon are reasonably explained. The main deformation mechanism gradually transforms into dislocation slip and climbing with temperature.