热轧双相钢塑性变形和断裂行为的研究

文章利用SEM、TEM研究了热轧双相钢单向拉伸过程中不同变形量下的形变位错结构和断口组织特征。结果表明,双相钢中铁素体的塑性变形是由位错增殖、位错运动和交互作用、滑移带形成、位错缠结产生及其密度的增加、位错胞出现及细化等一系列演变构成;变形10%时,板条马氏体已产生塑性变形,其板条中出现形变带,并且随马氏体变形的继续,形变带不断形成和发展。变形颈缩时,双相钢中的微孔主要通过相界面结合力的丧失和马氏体断裂产生,而马氏体断裂主要出现在马氏体的尖角处。

A study on plastic deformation and fracture of hot rolled dual-phase steel

The deformation dislocation structures and the fracture microstructure of hot rolled dual phase (DP) steel at different deformation extent in uniaxial tension were studied by SEM and TEM in this paper.The results showed that plastic deformation of ferrite in DP steel was composed of a series of evolutions,such as dislocation multiplication,dislocation movement and interaction,the appearance of slip band,the form of the dislocation tangle and the increase of dislocation density,the appearance and refinement of dislocation cell and so on.Lath martensite had occurred plastic deformation after 10% deformation.And then the plastic deformation of martensite was along with the form and growth of the deformation band.Furthermore,when necking began,the micropore in DP steel was formed by the disappearance of binding force at phase boundary and the fracture of martensite.And the most of the fractures of martensite were obtained at the sharp corner of the martensite.