Production Process Of Cold Drawn Steel Wire

‌The production process of cold drawn steel wire mainly includes core steps such as raw material selection, cold drawing deformation, straightening, cutting and surface treatment, among which stress control, deformation amount and speed adjustment during cold drawing are particularly critical. ‌ ‌
The specific process is as follows:

Main process flow
‌Raw material preparation‌

Select low/medium carbon high-quality carbon structural steel or alloy structural steel wire, and the chemical composition must strictly control the oxygen, phosphorus and sulfur content to ensure that there are no defects such as folding and scratches on the surface.

The wire is usually pickled or sandblasted to remove the oxide scale to ensure the surface is clean.
‌Cold drawing deformation‌ (core link)

‌Multi-pass cold drawing process‌: Apply tensile stress exceeding the yield strength of the material at room temperature, gradually reduce the cross-section and increase the strength through plastic deformation.

The yield point of the steel bar is increased after the first cold drawing, and the second cold drawing is further strengthened (deformation hardening effect).
‌Control parameters‌:
‌Dual control method (stress + cold drawing rate)‌ is preferably used for prestressed steel wire to ensure stable quality.
The cold drawing speed is generally controlled at 0.5-1.0 m/s, and the residual stress needs to be released after 2-3 seconds of stopping.
The grain size is controlled at 5-7 levels to balance strength and forming performance.
‌Intermediate treatment‌ (applicable to some processes)

Alloy cold heading steel wire needs to be spheroidized annealed to improve cold heading performance.
‌Subsequent processing‌

‌Straightening‌: Eliminate the bending caused by cold drawing, usually mechanical or flame straightening.
‌Cutting‌: Segment according to the required length, using sawing or shearing.
‌Surface treatment‌: Including polishing, galvanizing, etc., to improve corrosion resistance.
‌Quality inspection‌

Throughout the entire process, focus on testing non-metallic inclusions (Class B ≤15μm from the surface), dimensional tolerance (±0.20mm) and mechanical properties.