T92锅炉钢649℃长期时效的微观组织研究  

Microstructure of steel T92 under long-time aging at 649 ℃

作　　者：王双宝[1] 伍翠兰[1] 元敏[1] 杨浩[1] 陈江华[1] 

机构地区：[1]湖南大学材料科学与工程学院高分辨电镜中心,长沙410082

出　　处：《南京大学学报（自然科学版）》2009年第2期269-274,共6页Journal of Nanjing University（Natural Science）

基　　金：科技部973项目(2008CB617608;2009CB623704)

摘　　要：T92锅炉钢是用V、Nb元素微合金化的9Cr-0.5Mo-1.8W-VNb铁素体钢.本文研究了T92钢在649℃下经过1000、3000、5000和8000h不同时间的长期时效的微观组织的变化,并与其原始状态的微观组织进行了比较,发现随着时效时间的延长碳化物析出数量增加、尺寸略长大;碳化物类型主要为M23C6,而MX和Laves含量很少;板条状的基体组织形貌在长期时效过程中变化不大,即使经过649℃,8000h时效,仍保留板条马氏体的形貌.The steel T92 sample under this investigation is ferritic steel with a composition of 9Cr - 0.5Mo - 1.8W - VNb with V and Nb as the microalloying elements. The microstructure evolution of the T92 steel （aged at 649 ℃ for different times of 0, 1 0O0, 3 000, 5 000 and 8 000 hours, respectively） was investigated using optical microsco- py, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and Energy Dispersive Spectro- graph （EDS） analysis. It was found that the number and the size of the main precipitates in the steel increased with the aging time; these precipitates are mostly the M2aC6 carbides, the MX carbonitrides and the Laves phase parti- cles. The MX carhonitride and the Laves phase particles are relatively less than the Mz3C6 carbides. It is shown that apart from the precipitates, the micro-structural morphology of the steel has not been changed much during the en- tire aging process. That is, the martensite laths remain nearly unchanged even for an aging of 8 000 hours at 649 ℃.

关 键 词：锅炉钢 时效 碳化物 板条马氏体 

分 类 号：TG115.5[金属学及工艺—物理冶金] O346.2[金属学及工艺—金属学]