【摘要】 借助光学显微镜和透射电镜,研究了SAVE12钢的微观组织。结果表明,蠕变前后SAVE12钢组织主要为马氏体,也有少量δ-铁素体。蠕变前SAVE12钢中主要存在3种析出相,分别为富Nb的MX相,富Cr的M23C6相和富Fe的M5C2相。蠕变后部分MX相发生三点变化:Nb元素少量下降,其它金属元素少量增加;Nb元素较大下降,而Ta和W元素较大增加,变成富Ta的MX相;Nb元素较大下降,而Cr和V元素较大增加。蠕变后M23C6相化学成分基本没有变化,但析出量增加,且颗粒尺寸长大的不明显。蠕变后在δ-铁素体中有Laves相析出。更多还原

【Abstract】 Microstructure of SAVE12 steel was investigated by means of optical microscope and transmission electron microscopy.Experimental results show that the microstructure of SAVE12 steel before and after creep consists of martensite and a little δ-ferrite.SAVE12 steel before creep contains three kinds of precipitated phases,which are Nb-rich MX phase,Cr-rich M23C6 phase and Fe-rich M5C2 phase.Three changes appear in some MX phases after creep:Nb decreases slightly accompanied with slight increase of other metallic elements;Nb decreases obviously while Ta and W increase significantly,changing into Ta-rich MX phase;Nb decreases and Cr and V increase obviously.No change of size and chemical composition of M23C6 phase is observed,however,the amount of M23C6 phase increases for the steel after creep.Laves phase is precipitated in δ-ferrite after creep.更多还原