Relationship between mesoscale structure and ductility of drawn high carbon steel wire

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2021-01, Vol.800, p.140283, Article 140283
• Main Authors: Gondo, Shiori, Tanemura, Rena, Mitsui, Ryuki, Kajino, Satoshi, Asakawa, Motoo, Takemoto, Kosuke, Tashima, Kenichi, Suzuki, Shinsuke
• Format: Article
• Language: English
• Subjects: Carbon steel; Crystal orientation; Crystal structure; Diameters; Diffraction patterns; Drawability; EBSD analysis; Electron backscatter diffraction; Elongation; Evolution; Fiber texture; High carbon steel wire; High carbon steels; Mechanical properties; Mesoscale phenomena; Reduction; Reduction of area; Steel wire; Strain; Tensile strength; Tensile tests; Texture; Thickness; Wire drawing
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2020.140283

This study describes the evolution of a mesoscale structure that was characterized using fiber textures and mechanical properties versus drawing strain up to the drawing limit: the wire was drawn without causing rupturing, for the drawn high carbon steel wires (initial diameters: 0.276, 0.444 and 0.936 mm). Crystal orientation analysis using an electron backscatter diffraction pattern showed that the evolution of the mesoscale structure followed four steps with increasing drawing strain, regardless of the initial wire diameter. First, the wire consisted of only a primary fiber texture {100} −{111} . Second, the wire had primary and secondary {110} −{111} fiber textures in the outer and inner sides, respectively. Third, the wire had subprimary {100} −{111} and secondary fiber textures in its outer and inner sides, respectively. Fourth, the wire only consisted of a subprimary fiber texture. Results obtained through tensile testing showed that uniform elongation increased but the reduction of area decreased as the initial diameter increased over the entire drawing strain range, when there were no differences in lamellar spacing and tensile strength for the patented wires. Furthermore, uniform elongation decreased but the reduction of area increased when the ratio of thickness of secondary fiber texture to the wire radius increased. This study suggested that maintaining the thickness of secondary fiber texture in a large drawing strain region contributes to the improvement of drawability. [Display omitted] •Primary, secondary (S), and subprimary fiber textures are formed by wire drawing.•Mesoscale structure characterized by fiber textures follows 4 steps during drawing.•Elongation is inversely proportional to ratio of S thickness to wire radius.•Reduction of area is proportional to ratio of S thickness to wire radius.