The production process of stainless steel wire rope is a complex one involving metallurgy, metal processing and precision manufacturing. It can roughly be divided into three main stages: raw material preparation (wire drawing), strand twisting and rope joining, and post-treatment.

Phase One: Raw material Preparation - from coil to steel wire

The objective of this stage is to process the relatively coarse stainless steel raw materials into fine steel wires that meet the requirements.

Raw materials (pan yuan) :

Production begins with the purchase of stainless steel "coil elements", which are hot-rolled coiled stainless steel round bars, and the materials are usually 304, 316, 304L, 316L, etc. Its diameter is relatively large, generally above 5.5mm.

Pretreatment

Mechanical rust removal: There is an oxide scale on the surface of the disc element, which needs to be initially removed by mechanical methods (such as repeated bending).

Pickling: Immerse the coil element in an acidic solution (such as a mixture of nitric acid and hydrofluoric acid) to thoroughly remove the surface oxide scale and impurities, exposing a clean metal surface.

Coating (lubricating carrier) : After cleaning, apply a thin layer of lime or borax on the smooth surface of the disc element as a lubricating carrier. This coating can adsorb lubricants and reduce friction in subsequent wire drawing.

"Wire pulling

This is a cold working process in which the coil element is forcibly drawn through the die hole to reduce its diameter, increase its length and enhance its strength.

Rough drawing: First, perform multiple rough drawing passes to rapidly reduce the diameter to the intermediate size.

Intemediate heat treatment (recrystallization annealing) : During the drawing process, the steel wire will become hard and brittle due to "cold work hardening", and annealing is required to eliminate internal stress, reduce hardness and restore plasticity in order to continue drawing. Annealing is carried out in a protective atmosphere (such as hydrogen) to prevent oxidation of the steel wire surface.

Finished product heat treatment

After the wire drawing is completed, according to the customer's requirements for the performance of the steel wire (such as strength and toughness), a final solution treatment may be needed to achieve the best comprehensive performance of the steel wire.

Phase Two: Strand twisting

Twist multiple qualified steel wires around a center to form a "strand".

Twisting stran

A certain number of steel wires (such as 7 or 19) are twisted through a twisting machine.

At the center is a steel wire, surrounded by other steel wires, which are twisted together at a specific lay (the pitch of the helix) and lay direction (such as the right alternating lay "ZS") to form a strong helical structure.ds

Phase Three: Rope combination and post-processing

This is the step of combining multiple strands with the rope core to form the final steel wire rope.

Combined rope

Twist several strands (such as 6 strands or 8 strands) around a rope core to form a rope.

The rope core is a key component of steel wire ropes, and its function is:

Support strands: Maintain the circular cross-section and structural stability of the steel wire rope.

Oil storage and lubrication: Reduce internal friction and extend service life.

Increase flexibility.

The rope core can be a fiber core (FC, such as sisal, synthetic fiber), a metal core (WC, such as independent steel wire rope core IWRC), etc. Stainless steel wire ropes commonly use stainless steel wire rope cores or cotton-free rope cores (such as polypropylene cores) to prevent corrosion.

Post-processing

Stabilization treatment (pre-tensioning) : Apply a tension close to 60%-80% of the breaking force to the assembled steel wire rope to make the internal stress uniform, "shape" the structure, and reduce the structural elongation in the initial stage of use.

Lubrication: Throughout the entire production process and on the final product, dedicated lubricants are used for lubrication to reduce wear and corrosion.

Inspection and packaging

Final inspection: including diameter measurement, breaking tensile force test, lay length inspection, appearance inspection, material certification, etc., to ensure that the product complies with standards (such as GB/T, DIN, ASTM, JIS).

Packaging: Usually wound on I-beams or wooden wheels for protection to prevent damage during transportation and storage.