When planning a spring wire drawing production line, the key is to clearly define your product positioning (such as the target wire diameter range and the purpose of the spring), which directly determines the type of equipment and process path required. At the same time, it is important to find a balance between energy conservation and environmental protection (such as treating pickling wastewater) and improving the degree of automation, which can significantly improve production efficiency and product qualification rate.
🔧 Analysis of key processes and equipment
Raw Material Pretreatment: Wire rods often have scale on their surface, which requires removal through mechanical rust removal (e.g., shelling) or chemical pickling. Phosphating and saponification treatments then form a lubricating layer on the wire surface to reduce friction during drawing. For example, a high-pressure water rinse pressure of no less than 0.60 MPa is recommended after phosphating.
Wire Drawing: This is the core step and is carried out in stages based on the target wire diameter:
Rough Drawing/Intermediate Drawing: Typically, a straight-line or pulley-type drawing machine is used to draw the wire from a larger diameter (e.g., 6.5 mm) to an intermediate size (e.g., 5.0 mm).
Finish Drawing: To achieve precise final dimensions (e.g., φ2.5mm or finer) and excellent surface quality, a straight-line finish drawing machine or a water-cooled wire drawing machine is used. This stage requires precise control of the partial compression ratio (for example, one study reduced the partial compression ratio from 17.96% to 15.91% to increase throughput) and the drawing speed.
Heat Treatment: Heat treatment is crucial for restoring the material's plasticity and adjusting its mechanical properties.
Intermediate Annealing: If severe work hardening occurs during multiple drawing cycles, intermediate annealing is required to restore plasticity.
Finished Product Quenching and Tempering: A combined quenching and tempering process is often used for finished spring steel wire. For example, some processes use a quenching temperature of 900-950°C and a tempering temperature of 450-460°C to achieve high elasticity and toughness.
Surface Treatment and Spring Coiling: After wire drawing, the wire surface is oiled online to prevent rust and provide lubrication for subsequent processing, or undergoes electroplating and other treatments. Finally, the wire is coiled into various spring shapes using CNC spring machines (such as 8- or 10-axis machines). These machines can produce springs with diameters ranging from 0.2 mm to 2.5 mm, and even larger.
