一种核级316LN钢的相图计算与微合金化设计

Phase diagram calculation and micro-alloying design of nuclear grade 316LN steel

用热力学方法计算了一种核级316LN钢及其在Nb、V微合金化条件下的伪二元平衡相图,研究了不同温度下钢的平衡相组成。结果表明,316LN钢中的主要析出相为Cr2N、M23C6、和相,Nb微合金化316LN钢中会形成含C的MX,有望提高材料的力学性能和耐晶间应力腐蚀性能,V微合金化316LN钢中会形成VN,但对稳定C的作用不大。

Pseudo-equilibrium phase diagrams of non- and micro-alloyed nuclear grade 316LN steels are calculated through the thermodynamic method. The phase contents of the steels under different temperatures are also studied. It is found that under equilibrium conditions the precipitates in 316LN steel are Cr2N, M23C6, X and aphase, C-containing MX is observed to form in the Nb micro-alloyed 316LN steel, which might enhance the mechanical properties and intergranular stress corrosion resistance; VN almost has no significant effect in stabilizing C in the V micro-alloyed 316LN steel.