Metallurgy Chains: The key link in the steel industry

In the huge system of modern steel industry, Metallurgy Chains, as an indispensable key component, plays an important role in connecting various production links and ensuring the smooth operation of the production process. From the transportation of raw materials to the output of finished steel products, Metallurgy Chains run through every stage of steel production. The quality of its performance directly affects the production efficiency, product quality and production cost of steel enterprises. ​

1. What are Metallurgy Chains

(1) Definition and scope

Metallurgy Chains usually refer to various special chains used in metallurgical production and equipment. Since most of these chains are used in steel enterprises, they are often called steel mill chains. They cover a variety of types, including roller chains, block chains, pin chains and other different structural forms to meet the diverse working conditions in the steel production process. ​

(2) Differences from ordinary chains

Compared with ordinary conveyor chains, Metallurgy Chains have significant special features. Ordinary chains are generally used in more conventional material conveying or transmission scenarios, with relatively mild working environments, and the performance requirements for chains are mainly concentrated on basic strength and wear resistance. Metallurgy Chains, on the other hand, need to operate in extremely harsh environments such as high temperature, high humidity, high dust, strong corrosion, and huge loads. For example, in a hot-rolled wire production line, the chain needs to be in a high temperature state for a long time, while also bearing the weight of the wire and the impact of movement; in a billet and ingot continuous casting production line, the chain not only has to face the radiant heat of high-temperature molten steel, but may also come into contact with cooling water containing corrosive substances. Therefore, Metallurgy Chains have more stringent and special requirements in terms of material selection, structural design, manufacturing process, and heat treatment to ensure that it can operate stably and reliably under harsh working conditions and meet the high-intensity requirements of steel production.​

2. Application scenarios of Metallurgy Chains​

(1) Hot-rolled wire production line​

In the production process of hot-rolled wire, Metallurgy Chains are responsible for transporting the heated billet to the rolling mill for rolling, and for transporting the rolled wire to subsequent cooling, coiling and other processes. Chains need to be resistant to high temperatures, high strength and good wear resistance to adapt to the continuous impact of high-temperature wire and long-term high-speed operation. For example, in a high-speed wire finishing mill, the chains need to run synchronously at extremely high speeds to ensure that the wire can accurately and stably enter each roller for rolling. Once the chain fails, the entire production line will be interrupted, causing huge economic losses. ​

(2) Continuous casting production line for billets and ingots​

In the continuous casting production line, Metallurgy Chains are used to pull the billet out of the crystallizer and transport it to the cutting equipment for cutting to size. Since the temperature of the billet is high during the drawing process and there may be impurities such as iron oxide on the surface, the chain must not only bear the weight of the high-temperature billet, but also resist the wear of the iron oxide and the erosion of the cooling water. At the same time, in order to ensure the quality of the billet and the continuity of production, the chain must run smoothly and accurately, and its pitch accuracy and synchronization must be extremely high. For example, in a large slab continuous casting machine, a slight deviation of the chain may cause defects such as cracks in the billet, affecting product quality. ​

(3) Billet processing conveyor line​

Metallurgy Chains in the billet processing conveyor line are responsible for conveying the billet from the heating furnace to various processing equipment, such as forging machines and rolling mills. In this process, the chain needs to start, stop and reverse frequently to match the rhythm of different processing steps. In addition, a large amount of heat and debris will be generated during the processing of the billet. The chain needs to have good heat resistance and anti-chip embedding ability to prevent the debris from entering the chain joints and causing jamming or increased wear. For example, in a forging workshop, the chain must withstand the strong vibration and impact generated when forging steel billets, and at the same time maintain stable operating performance in a high temperature environment. ​

(4) Steel coil processing production line

In the steel coil processing production line, Metallurgy Chains are mainly used to transport and convey steel coils to complete a series of processing procedures such as uncoiling, leveling, shearing, and recoiling. The chain needs to have sufficient strength and rigidity to carry steel coils weighing several tons or even tens of tons, and ensure the stability and positioning accuracy of the steel coils during transportation. At the same time, since the surface of the steel coil is relatively smooth, the control of the friction between the chain and the steel coil is also very critical, ensuring that the chain can effectively drive the steel coil to move without scratching the surface of the steel coil. For example, in the high-precision automobile plate steel coil processing production line, the chain's running stability and positioning accuracy are extremely high, and any slight shake or deviation may affect the quality of the final product.​

(5) Steel pipe drawing production line​

In the steel pipe drawing production line, Metallurgy Chains are used to pull the steel pipe through the drawing die to achieve the steel pipe diameter reduction, wall reduction and other processing processes. The chain needs to withstand huge tensile forces during operation, and at the same time, it must adapt to the high-speed movement of the steel pipe and the frequent stretching and retraction actions during the drawing process. In order to ensure the drawing quality and production efficiency of the steel pipe, the strength, fatigue life and synchronization of the chain with the drawing equipment are crucial. For example, in the process of drawing large-diameter thick-walled steel pipes, the chain needs to withstand tensile forces of thousands of Newtons, and it must ensure that there will be no problems such as breakage or elongation deformation during long-term continuous operation. ​

3. Characteristics of Metallurgy Chains​

(1) High strength and high rigidity​

Because Metallurgy Chains need to bear huge loads during operation, such as carrying heavy steel billets and steel coils, they must have high strength and high rigidity. This requires that when designing and manufacturing the chain, high-quality alloy steel materials should be selected, and reasonable structural design and advanced processing technology should be used to ensure that every link of the chain can withstand heavy loads. For example, high-strength alloy steel is used to manufacture chain plates and pins, and they are subjected to special heat treatment to improve the strength and toughness of the materials so that they can withstand huge tensile and impact forces without breaking or deforming. ​

(2) Strong wear resistance​

In the steel production environment, a large amount of iron scale, metal powder, high temperature, high humidity and other factors will accelerate the wear of the chain. In order to improve the wear resistance of metallurgy chains, measures are usually taken in terms of material selection, surface treatment and structural design. For example, materials with good wear resistance are selected to manufacture rollers, sleeves and other easily worn parts, and their surfaces are hardened, such as carburizing and quenching; the structure of the chain is optimized to reduce the friction and wear points between the chain and the materials and equipment; special sealing structures are used at the chain joints to prevent dust, debris and other impurities from entering, thereby extending the service life of the chain.​

(3) Excellent high temperature resistance​

There are a large number of high temperature links in the steel production process, such as heating furnaces and hot rolling processes. Metallurgy Chains need to operate stably for a long time in a high temperature environment. For this reason, chains are usually made of high temperature resistant alloy materials and undergo corresponding heat treatment to ensure that they can still maintain good mechanical properties at high temperatures. At the same time, heat dissipation and thermal expansion issues are also considered in the structural design to avoid deformation or jamming of the chain due to high temperature. For example, some chains used in high temperature environments will use a special hollow pin structure to facilitate internal ventilation and heat dissipation, thereby reducing the temperature of the chain. ​

(4) Low-speed stable operation capability​

In some metallurgical production processes, such as billet traction in continuous casting production lines and steel coil handling in steel coil processing production lines, chains need to operate in a low-speed and stable manner. This requires Metallurgy Chains to have good low-speed stability, be able to maintain uniform motion at low speeds, avoid jamming, shaking, etc., to ensure the continuity of the production process and product quality. In order to achieve this goal, the pitch accuracy, roller and sleeve matching accuracy, etc. of the chain are strictly controlled during the manufacturing process, and appropriate lubrication methods are used to reduce the resistance and friction during chain movement. ​

(5) High reliability​

The production lines and equipment of steel plants usually operate continuously, with complex and diverse equipment and large equipment size. Once the chain fails, it will not only cause production interruption, but also may cause huge losses to the products and equipment produced. Therefore, Metallurgy Chains must have extremely high reliability and be able to operate stably for a long time under harsh working conditions. This requires strict control of all links from design, manufacturing, installation and commissioning to daily maintenance, and the use of advanced quality control methods to ensure that every component of the chain meets high quality standards. At the same time, a complete chain operation monitoring system is established to grasp the working status of the chain in real time and promptly discover and deal with potential fault hazards.

4. Production process of Metallurgy Chains

(1) Raw material selection

The selection of raw materials for Metallurgy Chains is crucial and directly related to the performance and quality of the chain. High-strength alloy steels are usually selected as the main materials, such as medium carbon steel, alloy structural steel, etc. These steels have good comprehensive mechanical properties and can meet the use requirements of chains under harsh working conditions such as high strength, high wear, and high temperature. When selecting raw materials, it is necessary to strictly control the chemical composition and physical properties of the steel to ensure that its purity, hardness, toughness and other indicators meet the relevant standards. For example, for some high-end Metallurgy Chains, alloy steels containing alloy elements such as chromium, nickel, and molybdenum will be selected to improve the strength, wear resistance and corrosion resistance of the chain.

(2) Processing and manufacturing process

Chain plate processing: First, the selected steel is processed into chain plate blanks of the required thickness and width through rolling, forging and other processes. Then, the chain plate blanks are punched, trimmed and other processes are performed using punching machines, CNC machining centers and other equipment to form the basic shape of the chain plate. During the processing, the dimensional accuracy and surface quality of the chain plates must be strictly controlled to ensure the connection accuracy and matching performance between the chain plates. For example, through high-precision molds and advanced stamping processes, the diameter tolerance of the pin holes on the chain plates is controlled within a very small range to improve the assembly accuracy of the chain. ​

Manufacturing of parts such as pins and rollers: Pins and rollers are key moving parts of the chain, and their manufacturing accuracy and quality directly affect the running performance of the chain. Pins are generally made of bar materials through turning, grinding and other processes, requiring high surface finish and precise dimensional accuracy. Rollers are usually manufactured through forging, machining and other processes. In order to improve the wear resistance of rollers, their surfaces are also subjected to heat treatment such as carburizing and quenching. For example, advanced CNC lathes are used to perform precision turning on pins to ensure that the cylindricity and surface roughness of the pins meet high precision requirements; by controlling the depth of the carburized layer and the quenching process parameters, the roller surface obtains high hardness and good wear resistance, while the core maintains sufficient toughness.​

Chain assembly: Assemble the processed chain plates, pins, rollers and other parts to form a complete chain. The assembly process needs to be carried out strictly in accordance with the design requirements to ensure that the installation positions of each component are accurate and the pitch of the chain is uniform. During the assembly process, special assembly equipment and tools, such as chain assembly machines and press machines, are usually used to ensure assembly quality and efficiency. At the same time, the assembled chain is strictly inspected for quality, including the length, pitch accuracy, tensile strength and other indicators of the chain. Only qualified chains can enter the next process. ​

(3) Heat treatment process​

Heat treatment is an important means to improve the performance of metallurgy chains. Through appropriate heat treatment processes, the organizational structure of the chain material can be improved, and its strength, hardness, toughness and wear resistance can be improved. Common heat treatment processes include quenching, tempering, carburizing, nitriding, etc.​

Quenching and tempering: For major parts such as chain plates and pins, quenching treatment is usually carried out first, heating them above the critical temperature, and then cooling them rapidly to make the material obtain martensitic structure, thereby improving hardness and strength. After quenching, tempering treatment is carried out to eliminate quenching internal stress, adjust the toughness and hardness of the material, and achieve the best comprehensive mechanical properties. For example, after quenching and tempering, the hardness of the chain plate can reach HRC40-50, and the strength is greatly improved, which can better withstand the load in work. ​

Carburizing and nitriding: For some parts that need to improve surface hardness and wear resistance, such as rollers and sleeves, carburizing or nitriding treatment is often used. Carburizing is to place the parts in a carbon-rich medium and heat them, so that carbon atoms penetrate into the surface of the parts to form a carburized layer of a certain thickness, and then quench and temper them to make the surface obtain high hardness and wear resistance, while the core still maintains good toughness. Nitriding is to make nitrogen atoms penetrate into the surface of parts to form a nitride layer, thereby improving the surface hardness, wear resistance, bite resistance and corrosion resistance of the parts. For example, after carburizing, the surface hardness of the roller can reach HRC58-63, which effectively improves its wear resistance during operation. ​

(4) Quality inspection link​

In order to ensure that the quality of Metallurgy Chains meets the standards and usage requirements, strict quality inspection is required during the production process. The quality inspection link runs through various stages such as raw material inspection, component processing inspection and finished chain inspection. ​

Raw material inspection: chemical composition analysis and mechanical property testing of purchased steel are carried out to ensure that the raw materials meet the design requirements. For example, the chemical composition of steel is accurately analyzed by a spectrometer to detect whether the content of elements such as carbon, silicon, manganese, phosphorus and sulfur is within the specified range; the tensile strength, yield strength, elongation and other mechanical properties of steel are tested by a universal material testing machine.​

Parts processing inspection: During the processing of chain plates, pins, rollers and other parts, measuring tools and inspection tools are used to detect key dimensions in real time to control processing accuracy. For example, calipers and micrometers are used to measure the thickness and aperture of chain plates; roughness meters are used to detect the surface roughness of parts. At the same time, the processed parts are visually inspected to ensure that there are no defects such as cracks, sand holes, and pores. ​

Finished product chain inspection: The assembled finished chain is fully inspected, including the length, pitch accuracy, tensile strength, fatigue life, hardness and other indicators of the chain. For example, the total length and pitch of the chain are measured using a chain length measuring instrument to ensure that it meets the standard requirements; the chain is tensile tested by a chain tensile testing machine to detect whether its tensile strength reaches the design value; the chain is fatigue tested by a fatigue testing machine to simulate the stress of the chain in actual work and detect whether it breaks or fails under the specified number of cycles. Only chains that have passed all tests can be delivered for use.​

5. Development Trend of Metallurgy Chains​

(1) Green and Environmental Protection​

As the world's attention to environmental protection and sustainable development continues to increase, the steel industry is facing tremendous pressure to save energy and reduce emissions. As an important part of steel production, Metallurgy Chains are also developing in the direction of green and environmental protection. On the one hand, in terms of material selection, there is an increasing tendency to use recyclable and low-pollution materials to reduce the impact on the environment. For example, new biodegradable coating materials are used to replace traditional coatings containing heavy metals and other harmful substances, thereby reducing environmental pollution during the production and use of chains. On the other hand, by optimizing the structural design and manufacturing process of the chain, the transmission efficiency of the chain is improved and energy consumption is reduced. For example, a new type of low-friction chain is developed to reduce the resistance of the chain during operation, thereby reducing the energy consumption of the drive motor and achieving the goal of energy conservation and emission reduction. ​

(2) Intelligence and Digitalization​

Under the general trend of Industry 4.0 and intelligent manufacturing, Metallurgy Chains are also gradually moving towards intelligence and digitalization. By installing intelligent devices such as sensors on the chain, the operating status of the chain, such as temperature, vibration, wear and other parameters, is monitored in real time, and these data are transmitted to the control system for analysis and processing. When the chain is abnormal, the system can issue an early warning in time, and automatically adjust the production parameters or take corresponding maintenance measures according to the preset program to realize the intelligent management and fault predictive maintenance of the chain. At the same time, digital design and manufacturing technology are used to improve the design accuracy and production efficiency of the chain. For example, computer-aided design (CAD) and computer-aided manufacturing (CAM) technology are used to perform virtual design and simulation analysis on the chain, optimize the structure and manufacturing process of the chain, reduce errors and waste in the design and manufacturing process, and improve product quality and production efficiency. ​

(3) High performance and long life​

With the continuous development of steel production technology, the performance requirements for metallurgy chains are getting higher and higher. In the future, metallurgy chains will develop towards higher strength, higher wear resistance, better high temperature and corrosion resistance, and longer service life. In order to achieve this goal, it is necessary to continuously develop new materials and manufacturing processes. For example, develop new high-temperature alloy materials and surface treatment technologies to improve the performance of chains in high-temperature and high-corrosion environments; use advanced nanotechnology to improve the organizational structure of chain materials and improve their comprehensive performance. At the same time, by optimizing the structural design of the chain, reduce stress concentration points and increase the fatigue life of the chain. For example, adopt new chain connection methods and joint structures to reduce stress concentration during the operation of the chain and extend the service life of the chain. ​

(4) Customized services​

Different steel companies have differences in production processes, equipment specifications, and working conditions, and their needs for metallurgy chains are also different. Therefore, in the future, metallurgy chain manufacturers will pay more attention to providing customized services to customers. According to the specific needs of customers, from chain design, material selection, manufacturing to installation and commissioning and after-sales service, provide a full range of personalized solutions. For example, for the high temperature and high wear conditions of a specific steel plant, a Metallurgy Chains with special materials and structural design is tailored for it, and professional installation guidance and regular maintenance services are provided to ensure that the chain can operate stably and reliably under the harsh conditions of the steel plant and meet the production needs of customers. ​

6. Conclusion​

As a key link in the steel industry, Metallurgy Chains plays an irreplaceable and important role in all aspects of steel production. Its special application scenarios and strict working requirements determine that it must have a series of excellent properties such as high strength, wear resistance, high temperature resistance, low-speed and stable operation, and high reliability. With the continuous development and technological progress of the steel industry, Metallurgy Chains has continuously innovated in production processes and has achieved significant improvements in material selection, processing and manufacturing, heat treatment, and quality inspection. At the same time, in order to adapt to the development needs of the times, Metallurgy Chains is continuing to develop in the direction of green environmental protection, intelligence and digitalization, high performance and long life, and customized services. In the future, with the continuous breakthroughs and applications of related technologies, Metallurgy Chains will continue to play an important role in the high-quality development of the steel industry and provide strong support for promoting the progress and upgrading of the steel industry. ​