摘要
铁素体耐热钢中的原奥氏体晶粒尺寸和"-铁素体演变行为与热处理温度密切相关。本文实验研究了正火处理温度对两种不同N含量的Fe-12Cr-2W-3Co-1Cu-0.12C-VTa钢显微组织演变规律的影响。结果显示:原奥氏体晶粒尺寸和"-铁素体含量随正火处理温度增加而增大;与N含量为0.02 wt.%的钢相比,N含量为0.08 wt.%的钢中MX相析出量和其溶解温度增高,MX相和固溶N对晶界钉扎和拖曳作用显著降低了晶粒粗化速率;N含量也对δ-铁素体含量变化具有很大影响,高N含量具有扩大奥氏体相区、抑制δ-铁素体形成的有益作用;基于实验研究,N含量为0.02 wt.%的Fe-12Cr-2W-3Co-1Cu-0.12C-VNb钢正火温度范围推荐值分别为1000~1030℃,而高N含量钢正火温度控制范围为1000~1070℃。
The evolution of prior austenite grain size and"-ferrite in ferritic heat resistant steels is closely related to heat treatment temperature.The influence of normalization temperature on the microstructural evolution of a Fe-12 Cr-2 W-3 Co-1 Cu-0.12 C-VTa steel with the variation of nitrogen contents was investigated in this study.The results showed that the prior austenite grain size and the content ofδ-ferrite increased with the increments of normalization temperature.Compared with the steel specimens with0.02 wt.%N,the specimens with 0.08 wt.%N showed reduced grain coarse rate.The pinning effects from MX phases and dragging effects of nitrogen solutes significantly reduced the grain coarse rate.The addition of nitrogen in Fe-12 Cr-2 W-3 Co-1 Cu-0.12 C-VTa steel was effective to enlarge the austenite region and restrict the formation ofδ-ferrite.The recommended temperature range of normalization for steels with 0.02 wt.%N was 1000~1030℃,and expanded to 1000~1070℃for steels with 0.08 wt.%N.
作者
赵卓
程利凯
高敏坤
ZHAO Zhuo;CHENG Likai;GAO Minkun(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;Shenyang Dong Chuang Precious Metal Material Co.Ltd,Shenyang 110000,China)
出处
《中国体视学与图像分析》
2020年第4期353-359,共7页
Chinese Journal of Stereology and Image Analysis
关键词
铁素体耐热钢
光学金相
原奥氏体晶粒
Δ-铁素体
ferritic heat resistant steel
optical metallography
prior austenite grain
δ-ferrite
