Steel wire rope is an important component with high strength, good elasticity, light weight, and good flexibility, widely used in various industries such as machinery, shipbuilding, mining, metallurgy, and forestry

It is a rope made of twisted steel wire, as shown in Figure 1. The fiber rope in the middle is called the core, and the steel wire twisted around the core is called the strand. The diameter of steel wire rope is generally 3.15-65mm, with a maximum thickness of 120mm, and the diameter of untwisted steel wire rope can reach 1000mm. In the early 19th century, in Europe, ropes made of iron wire were used in mines instead of hemp rope and iron chains; Later, steel wire ropes appeared. Steel wire rope has a wide range of uses and varieties. At the end of the 1970s, the production of ****** steel wire rope was about 0.3% of the total steel production. China began producing steel wire ropes around 1939 and can now produce many varieties. Steel wire rope is widely used in tensioning, pulling, lifting, hoisting, pulling, and other aspects.

The main production areas of steel wire rope include steel wire rope factories in Tianjin, Shanghai, Shenyang, Shaanxi, Jiangsu and other places. Its products are not only supplied for domestic use, but also exported to the Philippines, Singapore, Hong Kong, Spain, Canada, Egypt, Yemen, and other countries. The steel wire ropes imported into our country mainly come from Germany, Japan, the United Kingdom, Russia, South Korea, etc.

Compared with other ropes, steel wire rope has the advantages of high strength, good toughness, no noise, and easy use. The commonly used steel grades for rope making are 60, 65, 70, 75MnCuTi, etc., and their sulfur and phosphorus content shall not exceed 0.035%. The following figure shows a detailed dissection of the steel wire rope by Dagang Steel Wire Rope, visually demonstrating the composition of the steel wire rope including steel wire, steel strand, and inner core.

The reason why steel wire rope is widely used is because it has the following characteristics:

(1) Steel wire rope can transmit long-distance loads

(2) Steel wire rope can withstand various loads and varying loads

(3) Steel wire rope has high tensile strength, Shanxi Taiyuan steel wire rope comprehensive fatigue strength and impact toughness

(4) Steel wire rope has good wear resistance, earthquake resistance, and operational stability under high-speed working conditions

(5) Steel wire rope has good corrosion resistance and can work normally in harsh environments with various harmful media

(6) Steel wire rope has good flexibility and is suitable for various purposes such as traction, pulling, bundling, etc

(7) The load-bearing coefficient of steel wire rope is large, and it is reliable to use

(8) The steel wire rope has a light weight, making it easy to carry and transport

Raw materials: The wire rope drawing referred to here refers to a process in which raw materials undergo acid washing, phosphating, shell stripping, and billet opening, during which one or more pull-out processes are carried out to change their molecular structure and achieve the target diameter.

The raw materials include black metals with a diameter of 0.14-10.00mm and non-ferrous metals with a diameter of 0.01-16.00mm.

Acid washing: The process of using acid solution to wash away rust and rolled skin on the surface of steel wire rope raw materials. In the production process of steel wire rope, it is also called shell stripping, which mainly removes the oxide of the high wire to prevent impurities such as rust from affecting the opening of the billet and damaging the drawing die.

Phosphating: Simply put, it is the process of immersing materials in a phosphate solution to obtain a water-insoluble phosphate film on their surface. To some extent, it prevents corrosion.

Open billet: A hole of a certain shape, round, square, octagonal, or other special shape, in the center of various molds for drawing metal wires. When metal forcefully passes through the mold hole, its size and shape change.

Cold drawn wire: For ordinary round steel, if it is forcefully pulled through a hole slightly smaller than its diameter, the diameter of the round steel will decrease and the length will elongate. Repeating this process will further reduce the size of the round steel. After this plastic deformation occurs, the hardness of the steel will increase and the plasticity will basically disappear. In situations where plasticity is not required, only strength is required, such steel can be used.

Tempering: Because the molecular structure of the steel wire has been destroyed, only tempering can restore the internal structure of the steel wire again. In order to facilitate re drawing, it is not easy to break and can be pulled to the strength we want. Strength is what we call tensile strength. The strength is drawn by wire drawing, not by heat treatment. This is the difference between wire rope technology and mechanical processing technology. General strength: 1470 N/mm2, 1570 N/mm2, 1670 N/mm2, 21770 N/mm2, 1870N/mm2, 21960 N/mm2. The higher the strength, the stronger the tensile strength, but the poorer the toughness. So, we should choose the appropriate strength when selecting steel wire ropes. We can't just focus on high intensity. High strength steel wire rope has strong tensile strength, but is relatively weak in terms of wear resistance and flexibility.

Production process of steel wire rope - Twisted strand

The type, structure, and use of twisted strands depend on the type, structure, raw materials, and production process of the steel wire rope. Generally, carbon steel wire with a circular cross-section and a diameter of 0.1-6.0mm is used for steel wire ropes. When twisting sealed and semi sealed steel wire ropes, Z-shaped and other special-shaped steel wires are used. The types of steel wire ropes are classified according to their uses, including suspension bridge ropes and mining twisted strands, overhead cableway carrying ropes, transmission device traction ropes, elevator ropes, and tying ropes for bundling and towing goods. The variety of steel wire ropes is constantly increasing, and their structures are becoming increasingly complex. In addition to using various coated steel wires, stainless steel wires and bimetallic steel wires are also used. To ensure the ***** performance and reliability of the steel wire rope, it is required that the steel wire rope has sufficient strength, good flexibility, dense twisting, compressive strength, wear resistance, corrosion resistance, and fatigue strength, among which strength * * * is important.

The cross-sectional structure of steel wire rope includes point contact circular strands, line contact circular strands, surface contact circular strands, irregular strands, single-layer strands that do not rotate, sealed, and flat. The surface contact round strand steel wire rope is made by pulling the wire contact strands through a wire drawing die or roller die with the traction force of a twisting machine. Through die drawing, the cross-sections of the rope strands before and after deformation

There are two anti-corrosion measures in the stock: oil coating and plating.

All steel wire ropes must be coated with oil. The fiber core is immersed in oil, and the grease is required to protect the fiber core from rotting or rusting the steel wire, moisturize the fibers, and lubricate the steel wire rope from the inside. Surface oiling ensures that all steel wires in the rope strand are evenly coated with a layer of rust proof lubricating grease. For ropes used in mines with high friction and mining water, black oil grease with strong abrasion resistance and water resistance should be applied; For other purposes, apply red oil and grease with strong film-forming properties and good rust prevention performance, and require a thin oil layer for easy cleaning during operation.

The coating includes galvanizing, aluminum plating, nylon or plastic coating, etc. The price of galvanized electric hoists in Taiyuan is divided into thin coating of steel wire first plated and then pulled, and thick coating of steel wire pulled and galvanized. The mechanical properties of thick coating are lower than those of smooth steel wire rope, and it is suitable for use in severely corrosive environments. Aluminum plated steel wire rope is more corrosion-resistant, wear-resistant, and heat-resistant than galvanized steel wire rope. It is mainly used for fishing trawl ships and mines containing H2S, and is produced using the first plating and then pulling method. The steel wire rope coated with nylon or plastic is divided into two types: coated rope and coated strand combined rope. The former is used for static cables, while the latter is used for dynamic cables.

The winding process involves coiling the steel wire onto the spool of the twisting machine and rewinding it; The steel wire can also be directly wound onto the I-wheel from the wire drawing machine. Twist the steel wire into strands. Twisting machines include basket type, shaft tube type, tubeless type, and double twisting machine. For the schematic diagram of a 12 axis tubular twisting machine, 1 is the I-shaped wheel that holds the lower layer of rope strands, 2 is the rotating barrel that contains 12 I-shaped wheels filled with steel wire, 3 is the wire pressing tile that forms the strands, 4 is the traction wheel, and 5 is the winding wheel of the upper layer of rope strands. After one rotation of the barrel, the length of the rope strands drawn out by the traction wheel is the twist pitch of the strands.