摘要
研究了无碳化物高强度贝氏体钢正火后回火温度对其组织和性能的影响。结果表明,经920℃奥氏体化加热空冷及200~350℃回火,实验钢具有良好的强韧性。该温度范围回火获得的抗拉强度为1 370~1 472 MPa,断后伸长率为15%~16%,断面收缩率为47%~62%,冲击功AKV为76~86 J;组织主要为板条状贝氏体铁素体和残余奥氏体,即无碳化物贝氏体组织。550℃回火冲击值最低,出现贝氏体回火脆性,断口特征为沿晶脆性断裂。
The influence of tempering temperature on the microstructure and properties of high strength carbide-free bainite steel was studied. The results show that the experimental steel has good strength and toughness through air cooling after austenitizing at 920 ℃ and then tempering at 200-350 ℃. The mechanical properties obtained are R_m=1 370-1 472 MPa, A=15%-16%, Z=47%-62%, AKV=76-86 J. The microstructure mainly consists of lath bainite ferrite and retained austenite, namely carbide-free bainite tissue. Tempering at 550℃ has the lowest impact value due to bainite tempering brittleness, and the fracture surface shows an intergranular brittlesness fracture appearance.
作者
李晴
程巨强
LI Qing;CHENG Ju-qiang(College of Materials Science and Chemical Engineering, Xi'an Technological University, Xi'an 710021, Shaanxi, China)
出处
《铸造》
CAS
北大核心
2019年第8期844-847,共4页
Foundry
关键词
无碳化物贝氏体钢
空冷
回火温度
组织
性能
carbide-free bainite steel
air cooling
tempering temperature
microstructure
mechanical properties
