Thermodynamic study on equilibrium phase transformation and precipitation of 12Cr1MoVG steel
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摘要: 通过热力学软件JMatPro对12Cr1MoVG钢冷却过程中的相变和析出行为进行了研究,分析了钢中合金元素对纵裂纹敏感性的影响。结果表明,12Cr1MoVG钢从1600 ℃平衡冷却至400 ℃过程相变路径为:L→L+δ→L+δ+γ→δ+γ→γ→γ+MnS→γ+MnS+MN→γ+MnS+M(C,N)→γ+α+MnS+M(C,N)→γ+α+MnS+M(C,N)+AlN→γ+α+MnS+M(C,N)+M(C,N)+AlN+M23C6→α+MnS+M(C,N)+M(C,N)+AlN+M23C6。随着钢中P、S、Mo、V、Cr元素含量的增加,纵裂纹敏感性增加;而随着钢中Mn、Si元素含量的增加,纵裂纹敏感性降低。基于α+γ两相区温度区间和M(C,N)析出情况分析得到低温脆性温度区间为747.6~869 ℃,与拉伸试验测试结果基本一致。
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关键词:
- 12Cr1MoVG钢 /
- 纵裂 /
- 相变 /
- 热力学
Abstract: The phase transformation and precipitation behavior of 12Cr1MoVG steel during cooling were studied by thermodynamic software JMatPro, and the effect of alloying elements in the steel on longitudinal crack sensitivity was analyzed. The results show that the transformation path of 12Cr1MoVG steel from 1600 ℃ to 400 ℃ is L→ L+δ→ L+δ+γ→ δ+γ→ γ→ γ+MnS→ γ+MnS+MN→ γ+MnS+M(C,N)→ γ+α+MnS+M(C,N)→ γ+α+MnS+M(C,N)+AlN→ γ+α+MnS+M(C,N)+M(C,N)+AlN+M23C6→ α+MnS+M(C,N)+M(C,N)+AlN+M23C6. With the increase of P, S, Mo, V and Cr contents in the steel, the longitudinal crack sensitivity increases. While, the longitudinal crack sensitivity decreases with the increase of Mn and Si contents. Based on the temperature range of the (α+γ) two-phase region and the precipitation behavior of M (C, N), the low-temperature brittleness temperature range is calculated to be in the range of 747.6~869 ℃, which is basically consistent with the tensile testing results.-
Key words:
- 12Cr1MoVG steel /
- longitudinal crack /
- phase transformation /
- thermodynamics
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表 1 12Cr1MoVG钢主要化学成分
Table 1. Chemical composition of 12Cr1MoVG steel
% C Si Mn P S Als Cr Mo V Nb N 0.09~0.14 0.17~
0.350.45~
0.7≤
0.02≤
0.01≤
0.020.95~1.2 0.25
~
0.350.17
~
0.3≤
0.02≤
0.008 -
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