Wire production stage: From wire rod to finished wire (the most core and fundamental process) 

This stage is crucial for determining the strength, toughness and corrosion resistance of the steel wire rope. It requires multiple processes of cold drawing, heat treatment and surface treatment to transform the thick wire rod into fine steel wires of the specified diameter, while ensuring that the mechanical properties of the steel wires meet the standards. 

Surface pretreatment of wire rods 

Remove the oxide scale, rust and oil stains from the surface of the wire rod to prevent the mold from being damaged during drawing and to ensure the quality of the steel wire. 

Common processes: Acid washing (immersion in hydrochloric acid / sulfuric acid) → Water washing → Neutralization → Drying. Some environmentally friendly production lines use mechanical rust removal (shot blasting / wire drawing) instead of acid washing. 

Wire drawing (cold drawing wire) 

By using the multi-pass continuous cold drawing process, the pre-treated wire rods are passed through a series of hard alloy drawing dies with gradually decreasing diameters, and then drawn into steel wires with the diameters as required by the design (the diameters of the finished steel wires range from 0.15mm to 10mm). 

During the drawing process, the steel wire will undergo cold work hardening, resulting in an increase in hardness and a decrease in toughness. Therefore, heat treatment is necessary to restore its properties. 

Heat treatment (solution treatment) 

The steel wires after cold drawing are subjected to bath quenching with lead / water bath quenching followed by tempering, so that the internal structure of the steel wires forms a bainite (an ideal structure with both high strength and high toughness), ensuring the tensile strength and bending fatigue performance of the steel wires, and avoiding brittle breakage of the wire rope during use. 

This is the core process for manufacturing steel wires, and it directly determines the load-bearing capacity and service life of the steel wire rope. 

Surface treatment (anti-corrosion / wear-resistant processing) 

Adapting to the specific usage environment is crucial for the corrosion and wear resistance of steel wire ropes. The mainstream types can be classified into three categories: 

Smooth steel wire: After heat treatment, it undergoes surface phosphating and saponification, without coating. It is suitable for dry, non-corrosive indoor conditions (such as indoor lifting). 

Hot-dip galvanized steel wire: The steel wire is immersed in molten zinc liquid at high temperature for electroplating. The zinc layer is thick (the zinc layer weight is ≥ 300g/㎡), with strong corrosion resistance. It is suitable for outdoor, humid, and slightly corrosive conditions (such as in construction and ordinary marine environments). 

Electro-galvanized steel wire: Galvanized through electrolysis, the zinc layer is uniform and fine, with thickness precisely controllable. It is suitable for applications with high requirements for the appearance and uniformity of the coating (such as precision machinery, light-load marine use). 

Special conditions: It can also be treated with aluminized zinc or copper plating to enhance its high-temperature resistance and fatigue resistance. 

Wire inspection 

The tensile strength, repeated bending, torsion, coating adhesion and diameter deviation of the finished steel wire are tested. Any不合格 steel wires are directly removed to ensure the consistency of the quality of each individual steel wire.