V-N微合金化非调质钢的组织和力学性能  

Microstructure and mechanical properties of V-N micro-alloying non-quenched and tempered steel

作　　者：陆凤君[1] Lu Fengjun(School of Metallurgy and Automotive Engineering,Shandong Vocational College of Industry,Zibo Shandong 256414,China)

机构地区：[1]山东工业职业学院冶金与汽车工程学院,山东淄博256414

出　　处：《金属热处理》2024年第3期204-208,共5页Heat Treatment of Metals

基　　金：职业教育省级质量工程项目(202052)。

摘　　要：利用Gleeble-3500热模拟试验机研究一种V-N微合金化非调质钢,分析了V(C,N)的形变诱导析出特性,绘制了析出-温度-时间(Precipitation-Temperature-Time, PTT)曲线;设计了一种形变热处理工艺,利用金相显微镜(OM)、扫描电镜(SEM)和透射电镜(TEM)表征了微观组织,利用万能拉伸试验机测试力学性能。结果表明,在应力松弛过程中,V(C,N)的鼻尖析出温度在800℃左右,保温12 s后开始析出,90 s后析出结束。试验钢在800℃的变形量由15%提高到30%时,屈服强度和抗拉强度均逐步提高,分别提高了30 MPa和45 MPa,伸长率在11%~12%的范围内变化,冲击吸收能量由19.5 J提高到了25 J;随着等温变形量的增加,基体晶粒内部的位错密度显著增加,析出相数量增多并且分布更为弥散,晶内和晶界处均发现了长度在50~150 nm、宽度在20~50 nm尺寸范围的析出相。By studying a V-N micro-alloyed non quenched and tempered steel using thermal simulation testing machine, the strain induced precipitation behavior was analyzed and the Precipitation-Temperature-Time(PTT) curve was drawn. A thermomechanical treatment was designed, the microstructure was characterized by means of OM, SEM and TEM. The mechanical properties was tested by universal tensile testing machine. The results show that the precipitation temperature of V(C,N) at the nose tip is around 800 ℃ during the stress relaxation process, and it begins to precipitate after 12 and ends after 90. During the deformation process at 800 ℃, the yield strength and tensile strength gradually increase by 30 MPa and 45 MPa respectively, while the deformation amount increases from 15% to 30%. Elongation varies within the range of 11%-12%. The impact absorbed energy increases from 19.5 J to 25 J. With the increase of isothermal deformation, the dislocation density inside the matrix grains significantly increases, the number of precipitates increases, and the distribution becomes more dispersed. Precipitated phases with lengths ranging from 50 nm to 150 nm and widths ranging from 20 nm to 50 nm are found both within the grain and at the grain boundaries.

关 键 词：非调质钢 形变诱导析出 V(C N)相 位错 析出相 

分 类 号：TG156.2[金属学及工艺—热处理]