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用XRD、SEM、TEM和Mossbauer谱仪等手段,结合经验电子理论与热力学计算,对铬锰氮不锈钢的相组成与化学成分和热处理的关系,应变诱发马氏体相变、加工硬化、气蚀抗力及其与固溶体成分偏聚的关系进行了系统研究,取得了如下成果:①首次确定了铬锰氮不锈钢固溶体的价电子结构,并从理论和实验上证明了合金元素与N或C原子以强共价键形式呈短程有序编聚分布,以及对亚稳奥氏体的马氏体相变和加工硬化的影响规律;②首次提出用Ms点变化法研究奥氏体中碳化物的等温析出动力学,该方法比目前普遍采用的定量化学相分析及TEM方法更简便、快捷且灵敏度高;③发现气蚀使亚稳奥氏体铬锰氮不锈钢表面位错密度显著增大,并诱发γ→ε、ε→α′及γ→α′转变,同时也使铁近邻合金元素原子组态在相内的分布形式发生变化。经适当热处理后,这种钢的气蚀和磨蚀抗力显著优于目前国内外广泛采用的0Cr13Ni4～6Mo和0Cr16Ni5Mo钢。④发现高氮铬锰奥氏体不锈钢的气蚀抗力与含亚稳奥氏体铬锰氮不锈钢居同一水平,气蚀过程中其表面位错密度增高,气蚀区域出现细小二次孪晶和层错。
By means of XRD, SEM, TEM and Mossbauer spectroscopy, combined with empirical electron theory and thermodynamic calculation, the relationship between phase composition and chemical composition and heat treatment of chromium, manganese and nitrogen stainless steel, strain induced martensitic transformation, work hardening, cavitation Resistance and its relationship with segregation of solid solution were systematically studied and the following results were obtained: ① The valence electron structure of the solid solution of chromium, manganese and nitrogen stainless steel for the first time was confirmed, and the relationship between alloying elements and N or C atoms was proved theoretically and experimentally Strong covalent bond form was distributed in short-range order, as well as the martensitic transformation of metastable austenite and work hardening; ② For the first time using the Ms point change method for the study of austenite carbide isothermal Precipitation kinetics, the method is more convenient, faster and more sensitive than the quantitative chemical phase analysis and the TEM method commonly used; (3) cavitation is found to significantly increase the surface dislocation density of the metastable austenitic chromium, manganese and nitrogen stainless steel and induce γ → ε, ε → α ’and γ → α’ changes, and also changes the distribution of the atomic configuration of the iron alloy elements in the phase. After proper heat treatment, cavitation and abrasion resistance of this kind of steel are obviously better than 0Cr13Ni4 ~ 6Mo and 0Cr16Ni5Mo steel which are widely used at home and abroad. ④ It is found that the cavitation resistance of austenitic stainless steels with high nitrogen, chromium and manganese is in the same level as the metastable austenitic chromium, manganese and nitrogen stainless steels. The surface dislocation densities increase during the cavitation, and small secondary twins and cavitations occur in cavitations Layer fault.