The difference between steel stranded wire, steel cored aluminum stranded wire and aluminum clad steel cored aluminum stranded wire

Speaking of wires, we think of steel strands, steel cored aluminum strands, aluminum clad steel strands.Do you know where these are used and what is the difference? Today I will take you to find out.

Glanvanized steel strand

A steel strand is a steel product made by winding multiple steel wires. The surface of carbon steel can be added with galvanized layer, zinc-aluminum alloy layer, aluminum coating, copper coating, epoxy resin coating, etc. as required. Galvanized steel strands and aluminum-clad steel strands for electric power are also divided into 2, 3, 7, 19, 37 and other structures according to the number of steel wires. The most common structure is the 7-wire structure.

The manufacturing process of steel strands is divided into monofilament manufacturing and stranded wire manufacturing, and (cold) wire drawing technology is used when manufacturing monofilaments. According to the different materials of steel strand related products, it can be high carbon steel wire rod, stainless steel wire rod or medium and low carbon steel wire rod. If galvanizing is required, the monofilament shall be electroplated or hot-dipped.

ACSR

There are two stranding methods for ACSR: non-twisted stranding and twistless stranding. The wire core twisted by the untwisting method has no torsional internal stress, so it is mainly used for uncompressed multi-strand wires to prevent the internal stress from dispersing when a single wire is broken. Non-untwisting stranding is mostly used to tighten molded cores, because the residual stress generated by self-twisting is elastic deformation, while molding is plastic deformation, so the internal stress can disappear after tightening.

Regardless of whether the twist direction of the steel-cored aluminum stranded wire is concentric or composite, the outer layer is designated as the right (Z shape); the outer layer of the stranded insulated wire is the left side (S shape). Whether it’s right or left, its two adjacent layers twist in opposite directions. This is to unify the product, facilitate connection, and prevent loosening of individual wires. The drawing die is an important control point for the steel-cored aluminum stranded wire: the diameter uniformity of the steel-cored aluminum stranded wire, whether there are snakes, missing roots and jumping phenomena are all displayed here.

ACSR is made of twisted aluminum wire and steel wire, suitable for overhead transmission lines. According to our understanding, it is also seen that it has a steel “core” inside, and its exterior is wound around the steel core by twisting with aluminum wires; so its steel core mainly plays the role of increasing strength, and the aluminum stranded wire mainly plays the role of transmitting electric energy.

Aluminum Clad Steel Core Aluminum Stranded Wire

The raw materials for the production of aluminum-clad steel-reinforced aluminum strand include aluminum, steel wire and copper. Among them, aluminum is the main raw material because of its good electrical conductivity and light weight is also an advantage. Steel wire is used to increase the strength and rigidity of the strands, and copper is used to improve electrical conductivity and corrosion resistance.

The production process of aluminum-clad steel-reinforced aluminum stranded wire is mainly divided into the following steps:

Steel wire twisting: First, the high-strength steel wire is processed through a series of processes, including twisting and galvanizing, to increase its strength and corrosion resistance.

Aluminum cladding: The surface of the steel wire is coated with a layer of aluminum. This process is called aluminum cladding. Its purpose is to protect the steel wire from oxidation and corrosion, and it can also increase the adhesion between aluminum and steel wire.

Stranding: Aluminum-clad steel wires are twisted by mechanical twisting to form strands. In this process, factors such as the lay length, direction and number of layers of the twisted wire will have an impact on the performance of the twisted wire.

Extrusion: Coat the surface of the stranded wire with a layer of aluminum. This process is called extrusion. Its purpose is to protect the stranded wire from damage and corrosion, and it can also increase the adhesion between the aluminum and the stranded wire.

Heat treatment: The extruded stranded wire is heat treated to eliminate internal stress and improve the strength and stability of the material.

Packaging: Cut and pack the heat-treated aluminum-clad steel-reinforced aluminum stranded wire according to certain lengths and specifications for transportation and use.

The production process of aluminum-clad steel-reinforced aluminum strand needs to be optimized and controlled to ensure its performance and quality. Among them, process optimization mainly includes the optimization of process parameters such as steel wire, aluminum clad and stranded wire, so as to improve the performance such as adhesion and strength of aluminum clad and stranded wire. The process control mainly includes the control and monitoring of the entire production process to ensure that the produced aluminum-clad steel-reinforced aluminum stranded wire complies with relevant standards and specifications.

In terms of process optimization, the pretreatment of steel wire is very important, because it directly affects the quality of aluminum cladding. If the surface quality of the steel wire is not good, the adhesion of the aluminum clad to the steel wire will be reduced, resulting in a reduction in the strength and stability of the strand. Therefore, in the pretreatment process of the steel wire, proper cleaning and degreasing treatment should be carried out to ensure that the surface of the steel wire is clean, smooth and has good adhesion to the aluminum clad. In terms of the process parameters of aluminum clad and stranded wire, factors such as the thickness of the aluminum clad, the twist length and the number of layers of the stranded wire will have an impact on the performance of the aluminum clad steel cored aluminum stranded wire. In the process of process optimization, it is necessary to realize the performance of aluminum clad and stranded wire through reasonable parameter selection and adjustment.