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Custom 450是一种应用广泛的马氏体时效不锈钢,在工业生产中,冶炼方法和合金元素的批次差异会对其性能产生明显影响。通过Thermo-Calc热力学软件研究了不同温度下该钢的平衡相组成类型和含量,并结合室温力学性能测试,分析C、N、Nb含量的影响。结果表明:Custom 450试验钢的平衡相有α、γ、σ、NbNi_3、FCC-Cu、M_(23)C_6、Nb(C,N)和少量的Z-Cr Nb N、Laves相和χ相;随时效温度升高,材料抗拉强度和屈服强度降低,伴随着析出相类型转变和总质量分数的减少;C、N含量提高,使合金中平衡析出的碳化物及碳氮化物质量分数增加,金属间化合物平衡量减少;Nb含量的提高对总的碳化物及碳氮化物质量分数影响较小,而会促进金属间化合物质量分数的提高。
Custom 450 is a widely used martensitic stainless steel. In industrial production, batches of smelting processes and alloying elements can have significant effects on their performance. The type and content of equilibrium phase composition of the steel at different temperatures were studied by Thermo-Calc thermodynamics software. The effects of C, N and Nb contents were analyzed based on the mechanical properties at room temperature. The results show that the equilibrium phases of Custom 450 test steel are α, γ, σ, NbNi 3, FCC-Cu, M 23 C 6, Nb C and N, With the increase of aging temperature, the tensile strength and yield strength of the material decrease with the type transformation of precipitates and the decrease of the total mass fraction. With the increase of C and N contents, the mass fraction of carbides and carbonitrides which are equilibrated in the alloy increases, The balance of the intermetallic compounds decreases; the increase of Nb content has little effect on the total carbide and carbonitride mass fraction, but will promote the improvement of intermetallic compound mass fraction.