不同应变速率下TWIP钢力学性能及微观组织演变  

Mechanical Properties and Microstructure Evolution of TWIP Steel at Different Strain Rates

作　　者：周童 王荣吉[1] 彭松 王志宇 毛亮 ZHOU Tong;WANG Rongji;PENG Song;WANG Zhiyu;MAO Liang(School of Mechanical and Electrical Engineering,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学机电工程学院,湖南长沙410004

出　　处：《热加工工艺》2024年第22期134-139,共6页Hot Working Technology

基　　金：湖南省教育厅优秀青年项目(18B193)。

摘　　要：以Fe-Mn-C-Al系TWIP钢为研究对象,将试验钢通过退火热处理后在室温下进行拉伸,然后通过XRD、OM以及SEM等试验手段,研究了在不同应变速率下TWIP钢的力学性能、微观组织演变以及断口形貌变化规律。结果表明,不同应变速率拉伸后试验钢为单一奥氏体相,应变速率在3.33×10^(-4)~3.33×10^(-1)s^(-1)拉伸下,试验钢出现了再结晶以及二次孪晶,抗拉强度和伸长率在较低应变速率下处于较高水平,晶粒强化效果明显;随着应变速率的增大再结晶和二次孪晶的数量逐渐减少并消失,从而导致了抗拉强度和伸长率的减小。随着应变速率的增大,断口微观形貌由平整变得高低起伏,韧窝尺寸变大并由浅变深,材料脆性断裂的趋势越来越明显。Taking Fe-Mn-C-Al TWIP steel as the research object,the experimental steel was annealed and stretched at room temperature,and then tested by XRD,OM and SEM.The mechanical properties,microstructure evolution and fracture morphology of TWIP steel under different strain rates were studied.The results show that the test steel is a single austenite phase after stretching at different strain rates.Under the strain rate of 3.33×10^(-4)-3.33×10^(-1) s^(-1),recrystallization and secondary twins appear in the test steel.With the increase of strain rate,the number of recrystallization and secondary twins gradually decrease and disappear.This causes the reduction of tensile strength and elongation.With the increase of strain rate,the microstructure changes from flat to undulating,the dimple size increases from shallow to deep,and the brittle fracture trend of the material is more and more obvious.

关 键 词：TWIP钢 应变速率 力学性能 孪晶 断口形貌 

分 类 号：TG142.1[一般工业技术—材料科学与工程]