What are the production processes of steel wire rope?

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

It is a rope made of steel wire. See Figure 1 for its structure. The fiber rope in the middle is called the rope core, and the steel wire twisted around the rope core is called the rope strand. The diameter of steel wire rope is generally 3.15 ~ 65mm, the thickness can reach 120mm, and the diameter of untwisted steel wire rope can reach 1000mm. In the early 19th century, ropes made of iron wires were used in mines in Europe to replace hemp ropes and iron chains; Then came the steel wire rope. Steel wire rope has a wide range of uses and varieties. At the end of 1970s, the output of steel wire rope was about 0.3% of the total steel output. China began to produce steel wire rope around 1939, and now it can produce many varieties. Steel wire rope is widely used in tensioning, pulling, lifting, leading, pulling, etc.

The main production areas of steel wire rope are 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, etc. China mainly imports steel wire ropes from Germany, Japan, Britain, Russia, South Korea, etc.

Compared with other ropes, the steel wire rope has the advantages of high strength, good toughness, no noise and convenient use. The commonly used steel grades for rope making are 60, 65, 70, 75mncuti, etc., and the sulfur and phosphorus content shall not exceed 0.035%. The following figure shows the detailed anatomy of steel wire rope by large steel wire rope, and visually shows the composition of steel wire rope, including steel wire, steel strand and inner core.

Steel wire rope is widely used because it has the following characteristics:

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

(2) Steel wire rope can bear various loads and variable loads

(3) The steel wire rope has high tensile strength, great fatigue strength and impact toughness of Shanxi Taiyuan Steel Wire Rope

(4) The steel wire rope has good wear resistance, earthquake resistance and operation stability under high-speed working conditions

(5) The steel wire rope has good corrosion resistance and can work normally in the harsh environment of various harmful media

(6) The steel wire rope has good flexibility and is suitable for traction, pulling, binding and other purposes

(7) The bearing coefficient of steel wire rope is large and reliable

(8) The self weight of the steel wire rope is light and easy to carry and transport

Raw materials: the steel wire rope wire drawing here refers to a process means by which raw materials are pulled out once or more after pickling, phosphating, shelling and blank cutting, and their molecular mechanisms are changed to achieve the target diameter.

Raw materials include 0.14 ~ 10.00mm ferrous metals and 0.01 ~ 16.00mm non-ferrous metals.

Pickling: the process of removing rust and mill scale on the surface of raw materials of steel wire rope with acid. It is also called shelling in the production process of steel wire rope. It mainly peels the oxide of high-speed wire, so as to prevent rust and other impurities from affecting the blank opening and damaging the wire drawing die.

Phosphating: popularly speaking, it refers to the process of immersing materials in phosphate solution to obtain a layer of phosphate film insoluble in water on its surface. Prevent corrosion to a certain extent.

Blank: a hole of a certain shape, round, square, octagonal or other special shape, through the center of a die for drawing metal wires. When the metal is forced through the die hole, the size and shape change.

Cold wire drawing: if an ordinary round steel is forcibly pulled through a hole smaller than its diameter, the diameter of the round steel will become smaller and the length will lengthen. If the processing process is repeated continuously, the round steel will become smaller. After this plastic deformation, the hardness of the steel will increase and the plasticity will basically disappear. This kind of steel can be used when the strength is required instead of plasticity.

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 it 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 process and machining process. General strength: 1470n/mm21570n/mm21670n/mm21770n/mm21870n/mm21960n/mm2 The higher the strength, the stronger the tensile force, but the worse the toughness. Therefore, we should choose the appropriate strength in the selection of steel wire rope. You can't just be high-intensity. The tensile force of high-strength steel wire rope is strong, but it is weak in terms of wear resistance and flexibility.

Steel wire rope production process - strand twisting

The type, structure and use of strands the type, structure, raw materials and production process of wire rope depend on the use. Carbon steel wire with diameter of 0.1 ~ 6.0mm and circular section is generally used for steel wire rope. Z-shaped and other special-shaped wires shall be used when twisting sealed and semi sealed wire ropes. The types of steel wire ropes can be divided into: suspension bridge ropes and mine twisted strands, bearing ropes for overhead cableways, traction ropes for transmission devices, elevator ropes, tying ropes for binding and towing goods, etc. The variety of steel wire rope is increasing and the structure is becoming more and more complex. In addition to various coated steel wires, stainless steel wires and bimetal steel wires are also used. In order to ensure the serviceability and reliability of the steel wire rope, it is required that the steel wire rope has sufficient strength, good flexibility, compactness of twisting, compression resistance, wear resistance, corrosion resistance and fatigue resistance, among which strength is important.

The section structure of steel wire rope includes point contact round strand, line contact round strand, surface contact round strand, special-shaped strand, single-layer strand without rotation, sealing and flattening, etc. The surface contact round strand steel wire rope is made by drawing the wire contact strand through a wire drawing die or a roller die by the traction of the strander. Cross section of strands before and after deformation through drawing die

There are two kinds of anti-corrosion measures: oiling and plating.

Oiling all steel wire ropes must be oiled. The fiber core is immersed in oil, and the grease is required to protect the fiber core from decay and rust, moisten the fiber, and lubricate the steel wire rope from the inside. Apply oil on the surface so that all the steel wire surfaces in the rope strand are evenly coated with a layer of antirust lubricating grease. For the rope used in the mine with friction hoisting and large mineral water, it is necessary to apply black oil grease with strong abrasion and water resistance; For other purposes, red oil grease with strong film forming property and good rust prevention performance shall be applied, and the oil layer shall be thin to facilitate cleaning during operation.

The coatings are galvanized, aluminized, nylon coated or plastic coated. The price of Taiyuan electric hoist is divided into thin coating of steel wire after plating and thick coating of steel wire after galvanizing. The mechanical property of thick coating is lower than that of smooth steel wire rope, and it should be used in severely corrosive environment. Aluminized 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. It is produced by first plating and then pulling. The steel wire rope coated with nylon or plastic can be divided into two types: coated rope and stranded rope. The former is used for static cable, and the latter is used for dynamic cable.

In the winding process, the steel wire is coiled and rewound on the I-wheel of the stranding machine; The steel wire can also be directly rolled onto the I-wheel from the back of the wire drawing machine. To twist a steel wire into strands. Twister has basket type, axle tube type, tubeless type and double twister. It is the schematic diagram of the 12 axis tubular strander. 1 is the I-shaped wheel for installing the lower strand, 2 is the rotating barrel, which is equipped with 12 I-shaped wheels filled with steel wires, 3 is the strand pressing shoe, 4 is the traction wheel, 5 is the take-up wheel for the upper strand, the barrel rotates for one cycle, and the strand length led out by the traction wheel is the strand lay distance.