【摘要】 目的对服役时面临高温、高压、低温脆化、应力腐蚀、强中子辐照的反应堆压力容器（RPV）用材料进行成分分析并优化,提出一种材料优化的方法。方法利用CALPHAD方法以及Thermo-Calc软件对压力容器所使用的材料3级、4N级以及5级SA508钢进行析出相分析,并分析当C, Mn, Cr等合金元素含量变化时,各个析出相的变化,探究其中规律并从材料热力学角度进行相变分析和成分优化。结果 3级、4N级以及5级钢中析出相的区别主要在M₇C₃和M₂₃C₆;3级508钢中,当C的质量分数为0.20%与0.18%时,Mn含量均保持下限值,Cr含量均取拐点值,所选取合金成分可具有良好的性能。结论利用相图计算的方法可以实现核电压力容器材料进行成分的初步优化,但结果还需进一步精确化。更多还原

【Abstract】 The paper aims to propose a material optimization method through material composition analysis and optimization of reactor pressure vessel（RPV） facing high temperature, high pressure, low temperature embrittlement, stress corrosion and strong neutron irradiation. CALPHAD method and thermo-calc software were used to analyze the precipitated phase of SA508 steel of class 3, class 4 N and class 5 used in the pressure vessel, and analyze the changes of each precipitated phase when the content of C, Mn, Cr and other alloy elements changed, so as to explore the law and realize the phase transition analysis and composition optimization from the perspective of material thermodynamics. The main differences of precipitates in grade 3, 4 N and grade 5 steels were M₇C₃ and M₂₃C₆. In grade 3 508 steel, when the C mass fraction was 0.20% and 0.18%, the Mn content was kept at the lower limit, and the Cr content was defined as the inflection point value, the selected alloy components can have good properties. The phase diagram method can be used to optimize the composition of pressure vessel materials, but the results need to be further refined.更多还原