Research Progress on Hot Deformation Behavior of High Nitrogen Austenitic Stainless Steels: Influence Factors and Microstructure Control of Hot Deformation at High Temperature

High nitrogen austenitic stainless steels are an important engineering structural material. Under annealing conditions, the addition of interstitial solid solution element nitrogen can improve the yield strength and tensile strength of the alloy without reducing its plasticity. In addition, nitrogen can partly or completely replace the more expensive nickel element at a relatively cheap element cost to improve economic benefits, while maintaining or even enhancing the excellent corrosion resistance of stainless steels. However, the cracks and defects caused by high nitrogen austenitic stainless steels during hot working in high temperature ranges have always been the pain points in the engineering field. High nitrogen elements bring high temperature strength, but also narrow the hot working temperature range, the possibility of nitride precipitation and the tendency of heat induced cracking, which limit the further engineering application of high nitrogen austenitic stainless steels. It is urgent to analyze and study the hot deformation law of high nitrogen austenitic stainless steels in engineering. This article commences with an examination of the developmental trajectory of high nitrogen austenitic stainless steel, elucidates the role and strengthening mechanism of nitrogen, and delineates the factors influencing the mechanical behavior of high nitrogen austenitic stainless steel during hot working. These factors include the impact of nitrogen content and manufacturing processes, hot-working parameters, grain size distribution, and the presence of precipitated phases. This article synthesizes various studies, analyzes the causes of thermal cracking, and proposes potential solutions. Ultimately, it summarizes the practical applications and future prospects of high nitrogen austenitic stainless steel, highlighting its substantial potential.