The general reason about wire breakage in high carbon steel wire rod drawing are as follows:

  1. The surface quality of the wire rod is poor, and the rolled wire rod surface has scar and indentation defects. During the drawing process, a crack source is formed at the surface defects, which extends from the edge to the center and forms an oblique wedge fracture.
  2. The purity of molten steel is not high, and the content of non-metallic inclusions is high. From the metallographic examination, the inclusion particles are large, the oxide inclusion is up to B3, and the brittle inclusion mainly contains
    A203, SiO2, CaO and other composite oxides, as well as inclusions containing titanium. These inclusions do great harm to drawing and strand twisting. During cold drawing, it is very easy to form crack sources at the interface between steel matrix and brittle inclusions. With the increase of drawing surface reduction rate, the cracks expand into pores and eventually lead to fracture.
  3. The central segregation of continuous casting slab is serious, mainly C, Mn, P and s segregation. These component segregation are easy to produce abnormal structures after rolling, such as martensite, mesh secondary cementite and P and s segregation bands. They will become the fracture source in the subsequent drawing process. Because these structures are very brittle and easy to produce cracks, they will cause wire breakage during drawing. The fracture caused by the defects in the center of these wires is a sharp fracture on the macro surface.
    Measures to control wire breakage in drawing include:
  4. Surface quality. The factors affecting the surface quality of wire rod include slab quality and rolling. The defects of billet include slag inclusion, scab and microcrack, which can be solved by the control of secondary cooling water in casting. In terms of steel rolling, iron oxide scale is mainly pressed, folded and scratched. Strengthening inspection and process control can prevent surface defects.
  5. Optimization of post furnace refining process. The inclusions in the wire rod include A203, SiO2 and Cao brittle composite inclusions. By reducing the content of free oxygen in molten steel and controlling the basicity of slag in the process of post furnace refining, the size, shape and plasticity of inclusions can be improved and the purity of molten steel can be improved. Increase argon blowing time and flow rate to make large particle inclusions float fully; Carry out the plastic treatment of inclusions to change the brittle inclusions with high melting point into low melting point inclusions, so as to facilitate the deformation during cold working.
  6. Reduce the superheat of molten steel and control the central shrinkage, porosity and component segregation of billet. Control the matching of pouring temperature, billet temperature and drawing speed of molten steel, and use mold electromagnetic stirring and soft reduction technology to improve the carbon segregation and inclusion aggregation of high carbon steel and reduce the occurrence of brittle fracture caused by carbon segregation.

So-Lucky Steel as a china stainless steel coil and sheet supplier to all over the world, we attracts a number of skilled marketing personnel and skilled processing service team to support the business cooperation and promote the best quality steel to hundreds of places in the world. You can enjoy our customers service with goods supply, fast and convenient processing services at any time.