双相不锈钢热老化现象的研究进展

双相不锈钢兼具优异的力学性能、耐腐蚀性以及抗辐照能力,是核电站一回路主管道的关键结构材料。然而,在服役环境下长期工作,双相不锈钢中铁素体会发生调幅分解,生成富Fe的α相和富Cr的α′相,即产生热老化脆化现象,从而恶化合金的力学性能。本文综述了双相不锈钢的热老化机制,探索不同因素对合金相分解的影响,进而分析其微观组织及动力学演化规律。此外,利用计算机模拟平台对合金的相分解过程进行预测,可以缩短材料的研发周期和降低成本,对迫切解决双相不锈钢的热老化问题具有重要帮助。

Research progress on thermal aging of duplex stainless steels

Duplex stainless steels with excellent mechanical properties, corrosion resistance and radiation resistance are the key structural materials for the primary pipeline of nuclear power plant. However, in the service environment for a long time,the ferrite phase in the duplex stainless steel decomposes into the Fe-rich α phase and Cr-rich α′ phase by spinodal decomposition, which causes thermal aging embrittlement and deteriorates the mechanical properties of the steel. In this paper, the thermal aging mechanism of the duplex stainless steels is reviewed, and the influence of different factors on phase decomposition of the steels is explored, and the microstructure and kinetics evolution are analyzed. In addition, the use of computer simulation platform to predict the phase decomposition process of the steels can shorten the research and development cycle of new materials and reduce the cost, which is of great help to solve the problem of thermal aging of the duplex stainless steels urgently.