摘要
采用分离式霍普金森装置对30CrMnSiA的片式帽型试样进行动态剪切,利用光学显微、扫描电镜、透射电镜、显微硬度等金相分析方法对材料绝热剪切带的微观结构演化过程进行分析。研究发现,随着加载应变率的增大,剪切带发生由形变带到转变带的变化趋势,转变带呈"白亮"色,带内由尺寸约为50 nm的低位错、等轴晶粒组成,这是典型的再结晶晶粒特征。转变带形成过程可分为剪切变形、晶粒细化、晶粒断裂旋转、动态再结晶4个阶段。
The chip-hat-shaped specimen of 30CrMnSiA was used to study the dynamic shear behavior by the Split Hopkinson Pressure Bar (SHPB). The microstrueture evolution of adiabatic shear band was investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and microhardness. It is found that the deformation band changes to the transformation band with the loading strain rate increasing. The transformation band is a "white" band, which consists of a number of equiaxed grains about 51) nm in diameters with ~tow dislocation density, and these grains have typical recrystallized character. The microstructure evolution can be grouped into four stages: shear deformation, grains refinement, grains fracture and rotation stage, and dynamic recrystallization.
出处
《兵器材料科学与工程》
CAS
CSCD
2010年第6期59-61,共3页
Ordnance Material Science and Engineering