The Influence of a Multi-Pass Drawing Sequence on the Microstructure of 10 Carbon Steel Wire

The Influence of a Multi-Pass Drawing Sequence on the Microstructure of 10 Carbon Steel Wire

Drawing is the continuous deformation process that transforms a hot rolled wire or strip into a rod, bar or other shape for the purpose of industrial manufacturing.10 carbon steel drawing destructive This process can increase the strength and improve the ductility of the metal. However, the mechanical properties of steel depend on its initial state.

Among the most important is its tensile strength, which must be high enough for practical applications.10 carbon steel drawing destructive This property is dependent on the microstructure and is mainly determined by the grain size distribution. It is possible to control the growth of grains during drawing, thereby increasing tensile strength and improving ductility. In order to do so, it is necessary to understand the processes that govern the formation of a strong microstructure during this deformation. This article investigates the role of a multi-pass non-circular drawing sequence on the microstructure evolution and drawing behavior of carbon steel wire. The sequence was evaluated by tensile, fatigue and Vickers micro-hardness tests, and also by electron backscattering diffraction (EBSD).

The results show that the non-circular drawing sequence has a great influence on the development of a strong microstructure in the initial state.10 carbon steel drawing destructive Moreover, the multi-pass drawing sequence has a positive effect on the tensile and fatigue strengths of the low carbon steel wire. However, the microstructure evolution and drawing behavior during the process have to be further studied to obtain a more complete understanding of these effects.

To this end, the experimental and simulated evolution of the initial superficial longitudinal defect in a 10 mm diameter bar during 7 axisymmetric drawing passes is investigated.10 carbon steel drawing destructive The initial defects were 0.3 mm deep and exhibited a "V" shape with a surface opening. The drawing parameters were varied, including die semi-angles, area reduction per pass and the drawing speed. The result showed that the FEA simulations of the defect evolution were consistent with the experimental observations. The defect was closed at the surface of the bar after 2 drawing passes, while an internal overlap in the shape of an inverted Y remained in the drawn material.

In Fig. 13, the variation characteristics of the section shrinkage ps are shown in relation to the tensile deterioration sa and sea water concentration c, which were measured after the tensile test. It was found that ps was strongly dependent on sa and c, and its value dropped rapidly when these two variables increased.

The metallographic preparation of the drawing material was performed by polishing with SiC paper to 2000 grit, and then etching with 2% nital nitrate solution for 10 s. The EBSD micrographs of the defected areas were obtained using a Leica DM2700 M optical microscope. The results showed that, compared with the unprocessed sample, the ferrite/pearlite interface of the defect was smaller at the surface and larger within the depth of the defect. This led to a lower LL/Hi value of the deeper defect and a greater DSO/Wi value of the shallower defect. In addition, the defect was more elongated in depth with a greater drawing frequency.

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