超临界水冷堆燃料包壳管用低活性F/M钢的优化设计

应用热力学计算与实验验证，系统研究了Cr、W、C、Mn对高Cr低活性F/M（铁素体/马氏体）钢基体相及显微组织的影响规律，并在此基础上，对钢的组织和成分进行设计与优化，以适应超临界水系统对包壳材料的性能要求。研究表明：Cr是决定高Cr低活性实验钢中奥氏体Cr固溶量以及钢中是否出现铁素体的最重要影响因素;W和C对实验钢铁素体相的出现有显著影响，而Mn的影响相对较小;W对实验钢中Laves相出现的温度范围及数量具有显著影响，Laves相消失的临界温度随W量降低而降低;在不采用Co、Ni等奥氏体形成元素且不增加Mn量的情况下，通过调控W、C等含量，Cr含量≥11%的Cr-W-C-Mn系低活性F/M钢即可获得全马氏体组织。

Optimization Design of Reduced-Activation Ferritic/Martensitic Steels for SCWR Fuel Cladding Materials

Based on the combination of thermodynamic calculations and experimental verification, the influences of Cr, W, C and Mn on the microstructure and matrix phases of high-chromium reduced-activation ferritic/martensitic (F/M) steels were systematically studied. On this basis, the microstructure and chemical compositions of steels were optimized to meet the expectations of supercritical water system for cladding material performance requirements. Cr is the most important element which determines both the ferrite amount in the steel and the Cr solution amount in the austenite, while W and C also have significant impact on whether the ferrite appears in the matrix, though the influence of Mn is relatively small. The effect of W on the formation temperature JP2]and the amount of Laves phase is significant, and the critical temperature of Laves reduces withJP] lowering W content. Without adding austenite forming elements Co, Ni or increasing in the Mn content, ferrite phase can be avoided after normalizing-and-tempering heat treatment through appropriately adjusting the content of W, C, and other elements.