摘要
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 maraging stainless steel,and the melting method and chemical composition variations in different batches have a significant effect on its properties. The composition and content of equilibrium phases at various aging temperatures were investigated by thermodynamic software Thermo-Calc,and the effects of C,N and Nb content were also discussed by analyzing room temperature mechanical properties together with thermodynamics.The results indicate that the equilibrium phases between 760-640 ℃ comprise α,γ,σ,NbNi3,FCC-Cu,M（23）C6,Nb（C,N）and a small amount of Z-Cr Nb N,Laves and χ;with the increasing of aging temperature,the UTS and YS decrease with the transition of equilibrium phases and the reduction of total mass fraction of precipitations;in addition,the fraction of carbides and carbonitrides increase and the fraction of intermetallic decrease with the increasing of C and N content;the increasement of Nb content shows little effect on the fraction of carbides and carbonitrides,but improves the fraction of intermetallics.
出处
《连铸》
2017年第1期20-24,共5页
Continuous Casting
基金
冶15T60120B
