摘要
在1030-1120℃温度区间,对G115钢进行不同温度的正火处理随后进行780℃×3 h回火,并对其进行显微组织和650℃拉伸性能研究。拉伸结果表明：随正火温度的升高,650℃强度呈现“M”形变化特征。组织观察发现,1030℃时,晶粒重结晶未完全完成;随正火温度由1065℃升至1095℃,G115钢原奥氏体平均晶粒尺寸由38.40μm,减小至34.45μm左右,在1075℃至1095℃出现“平台”;当温度升至1120℃时,原奥氏体平均晶粒尺寸为67.64μm,长大明显。对不同正火温度试样扫描电镜（SEM）的背散射电子（BSE）观察,均发现较多的富W和Fe元素的Laves相。Laves相的尺寸和尺寸超过1000 nm Laves相所占的比例呈现“W”形变化特征。650℃强度随正火温度的变化规律主要与大尺寸的Laves相相关。
Normalizing treatment at different temperature from 1065 ℃ to 1120 ℃ were carried out G115 steel, then followed by tempering at780 ℃ for 3 h. Microstructure and 650 ℃ tensile test of the Gl15 steel with different normalization were also studied. Tensile test resultsshow ＂M＂-shaped change. The microstructure observation shows that with the increase of normalizing temperature, the prior austenite grain（PAG） size of the Gl15 steel decreases from 38.40 μm at 1065 ℃ to a platform between 1075 ℃ to 1095 ℃, which is about 34.45 p, ul,and then it increased obviously to 67.64 μm at 1120 ℃. Laves phases with rich tungsten and iron are also observed by BSE after normalizingat different temperatures. The size and percentage more than 1000 nm of Laves phase show ＂ W＂- shaped change characteristics afternormalizing at different temperatures. The change of 650 ℃ strength with increasing normalizing temperature is mainly associated with thelarge Laves phase.
出处
《金属热处理》
CAS
CSCD
北大核心
2018年第2期173-177,共5页
Heat Treatment of Metals
基金
重点基础材料提升与产业化重点专项(2017YFB0305205)
