High Temperature In Situ Optical Observation and Structural Optimization Numerical Simulation of High Nitrogen Steel (Cr18Mn18N)

As a steel with high strength, good plasticity and fracture toughness, high temperature resistance, and corrosion resistance, Cr18Mn18N is widely used in industrial engineering and military fields. However, in a high temperature environment, Cr18Mn18N needs to be subjected to higher temperature, resulting in excessive expansion deformation and larger stress, which will greatly damage the stability and service life of the material structure. In this paper, the high temperature arc wind tunnel is used to heat the high nitrogen steel material with prefabricated round structure, and the surface images of the material are collected at the temperature of 1500 K. After comparison, it is found that the material is well preserved in a high temperature environment, indicating that the circular structure has better thermal protection ability. Based on the experiment, the thermal-fluid-solid coupling model is established, and the surface temperature field, deformation field, and stress field are analyzed. Different surface structures are designed, and numerical models of horizontal and vertical splicing components are established. Through numerical simulation, the surface structure is optimized, the surface temperature of the material is reduced, and the gap change trend of the splicing component is displayed. This work has theoretical significance for the application of materials in a high temperature environment and the optimization and improvement of material surface structure.