Microstructural Development and Mechanical Properties of Multi-pass Cold Drawn Hypereutectoid

2018 3rd International Conference on Advanced Materials Research and Manufacturing Technologies

材料科学;机械制造

Chen, Z.H.^1 ; Wei, M.Z.^1 ; Zhang, X.M.^1 ; Wang, D.P.^1 ; Sun, K.^1 ; Zhou, J.^1,2 ; Xue, F.^1,2

Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing

211189, China^1

Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing Institute of Technology, Nanjing

211189, China^2

关键词: Accumulated strain;    Ferrite lattices;    Fibrous morphology;    High magnifications;    Hypereutectoid steel;    Lamellar morphology;    Longitudinal section;    Microstructural development;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/436/1/012018/pdf
DOI  :  10.1088/1757-899X/436/1/012018

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

In the present work, processes of multi-pass cold drawn were conducted on hypereutectoid pearlite steel wires with carbon content of 1.02 w.t.%. Relationship between microstructural development and mechanical properties of hypereutectoid steel wires after drawing was investigated. It was found that when the strain was relatively small, lamellar morphology of the pearlite in the steel wire after cold drawn remained, and the spacing of lamella was refined. With the increase of the compression ratio, coordinated deformation of ferrite and cementite occurred and pearlite lamella were bended and folded. As the strain increased, fibrous morphology of pearlite lamella was observed in longitudinal section of the wire. High magnification TEM observation revealed the fragmentation of cementite and a large number of nano-crystalline. Tensile strength, microhardness and torsion strength of the steel wires after multi-pass drawn process increased significantly with the increase of accumulated strain. The results of XRD analysis show that thepeak of the ferrite shifted to the left and widened following the multi-pass cold drawn deformation, indicating that the lattice constant of ferrite was increased. The increase of lattice constant of ferrite was the result of the distortion of ferrite lattice due to the dissolution of carbon atoms.