摘要
采用XRD、SEM和TEM等研究了650℃长时时效对12Cr-4W-3Co耐热钢显微组织及650℃高温强度的影响。结果表明:650℃时效0～5000h后,该钢的析出相为M_(23)C_6相和Laves相,高温屈服强度逐渐下降;在0～100h区间,屈服强度降低主要是由于马氏体板条回复较快;在100～1000h区间,M_(23)C_6、Laves相析出增加,板条回复减弱导致屈服强度基本不变;在1000～3400h区间,M_(23)C_6、Laves相的长大和板条的继续回复均导致屈服强度降低;在3400～5000h区间,板条的回复基本停止,M_(23)C_6、Laves相少量析出和长大的共同作用导致屈服强度基本不变。
The effect of long-time aging at 650℃ on microstructure and high temperature strength at 650 ℃ of the 12Cr-4W-3Co heat-resistant steel was studied by XRD, SEM and TEM. The results show that the precipitates were M23C6 and Laves phase when the tested steel aged at 650℃ for 0--5 000 h, the yield strength at high temperatures gradually decreased. The reduction of the yield strength was mainly resulted from the martensite lath recovery during 0--100 h. The yield strength was basically unchanged for the increase of M23 C6 and Laves phases precipitation and the decrease of martensite lath recovery during 100-1 000 h. The growth of M23C6 and Laves phases and recovery of the martensite lath led to the decrease of yield strength from 1 000 h to 3 400 h. During 3 400-5 000 h, the lath recovery stopped, and the yield strength basically unchanged for some precipitation and growth of M23 C6 and Laves phases.
出处
《机械工程材料》
CAS
CSCD
北大核心
2011年第3期56-59,共4页
Materials For Mechanical Engineering
基金
国际科技合作项目(2008DFB50030)
关键词
耐热钢
时效
高温强度
M23C6相
LAVES相
heat-resistant steel
aging
high temperature strength
M23C
phase
Laves phase
