P91耐热钢相变过程的原位观察  

In Situ Observation of Phase Transformation Process of P91 Heat Resistant Steel

作　　者：刘帆 王伟 顾文喜 牛广旭 LIU Fan;WANG Wei;GU Wenxi;NIU Guangxu(Gansu Special Equipment Inspection and Testing Research Institute,Lanzhou 730050,China)

机构地区：[1]甘肃省特种设备检验检测研究院,甘肃兰州730050

出　　处：《热加工工艺》2024年第8期42-45,共4页Hot Working Technology

摘　　要：采用激光共聚焦显微镜研究了P91耐热钢的组织变化规律。结果表明,温度升高到780℃时,组织向奥氏体(γ)转变;当温度达到965℃时,有微量的δ-铁素体产生;升温到1093℃时,P91表面晶界明显,并在升温中有块状δ-铁素体生成,直到1187℃左右时可见有大量的δ-铁素体,在1200℃保温时呈现不规则的多边形晶粒;在300℃/min的冷却速率下,在1164℃时组织为δ-铁素体并伴有少量的析出物,在909℃左右时已能看到δ-铁素体转化为奥氏体(α)的相变,这种相变也决定着残余δ-铁素体以及奥氏体(γ)相的数量和形态。A laser confocal microscope was used to study the microstructure variation of P91 heat-resistant steel.The results show that the microstructure starts to transform to austenite(γ)when the temperature rises to 780℃.when the temperature reaches 965℃,a trace amount ofδ-ferrite is emergent.The surface grain boundary of P91 is obvious when the temperature comes up to 1093℃,and there is lumphyδ-ferrite generated during heating.A mass ofδ-ferrite appear around 1187℃,and irregular polygonal grains are present at 1200℃.In the cooling rate of 300℃/min,the microstructure isδ-ferrite with a spot of precipitates at 1164℃.Theδ-ferrite to austenitic(α)phase transformation is observed around 909℃.This phase transition determines the amount and morphology of the residualδ-ferrite and austenite(γ)phases.

关 键 词：P91耐热钢 组织 原位观察 Δ-铁素体 相变 

分 类 号：TG151[金属学及工艺—热处理]