Technological process 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 twist, and its structure is shown in Figure 1. 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. At the beginning of the 19th century, ropes made of iron wires were used in mines in Europe to replace hemp ropes and chains; Later, steel wire rope appeared. 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 ropes around 1939, and now it can produce many varieties. Steel wire rope is widely used in tension, tension, lifting, lifting, leading, pulling and other aspects.

The main production areas of steel wire ropes 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, 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, which visually shows the composition of steel wire rope, including steel wire, steel strand and inner core.

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

(1) The steel wire rope can transmit long-distance load

(2) The 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) Under high-speed working conditions, the steel wire rope has good wear resistance, earthquake resistance and running stability

(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 steel wire rope is light, which is easy to carry and transport

Raw materials: the steel wire rope wire drawing here refers to a process means that the raw materials are pickled, phosphated, shelled and bloomed, during which one or more times of pulling are carried out to change its molecular mechanism and make it reach the target diameter.

Raw materials include ferrous metals with a diameter of 0.14 ~ 10.00mm and nonferrous metals with a diameter of 0.01 ~ 16.00mm.

Pickling: the process of washing away the rust and skin on the surface of raw materials of steel wire rope with acid, which 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 opening: a hole of a certain shape, round, square, octagonal or other special shape, through the center of the die for drawing metal wires. When the metal forcibly passes through the die hole, the size and shape change.

Cold wire drawing: for ordinary round steel, if it is forcibly pulled through a hole smaller than its diameter, the diameter of the round steel will be reduced and the length will be extended. If this processing process is repeated continuously, the round steel will be further reduced. After this plastic deformation, the hardness of steel will increase and the plasticity will basically disappear. This kind of steel can be used in occasions where plasticity is not required but strength is required.

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 drawing again, 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 technology and machining technology. 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 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 steel wire rope depend on the use. Generally, carbon steel wire with diameter of 0.1 ~ 6.0mm and circular section is used for steel wire rope. When twisting sealed and semi sealed wire ropes, Z-shaped and other special-shaped wires shall be used. The types of steel wire ropes are divided according to their uses: ropes for suspension bridges and mine twisted strands, bearing ropes for overhead cableways, traction ropes for transmission devices, ropes for elevators, 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 bimetallic 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 cross-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. Among them, the surface contact round strand steel wire rope is made by pulling the wire contact strand through the wire drawing die or roller die by the traction of the strander. Through the drawing die, the section of the rope strand before and after deformation

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

Oiling all steel wire ropes must be oiled. When the fiber core is soaked with oil, the grease is required to protect the fiber core from decay and rust, moisturize 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 lifting and large mineral water, it is necessary to apply black oil grease with strong wear and water resistance; For other purposes, red oil grease with strong film property and good rust prevention performance is applied, and the oil layer is required to be thin, which is convenient to keep clean during operation.

The coating includes zinc plating, aluminum plating, nylon coating or plastic coating. 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 a 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 in fishing trawl ships and mines containing H2S. It is produced by first plating and then pulling. Steel wire ropes coated with nylon or plastic can be divided into coated ropes and Stranded ropes. 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 strander; The steel wire can also be rolled directly onto the I-wheel from the back of the wire drawing machine. Twist the 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 twist distance.