COAL INDUSTRY
Industry needs
The working environment of coal machinery is complex and harsh, the equipment runs for a long time, and the load is large, especially in the humid environment of the well, various harmful gases, dust particles and other problems, which are easy to cause corrosion and wear to the mechanical equipment, which will greatly shorten the service life of the mechanical equipment. . The failure modes of these equipment are mainly wear, corrosion, scratches, etc., such as the wear failure of picks, scraper conveyor grooves, gears, shafts and other components, and the corrosion failure of hydraulic support column cylinders and piston rods. The components such as the column and cylinder of the hydraulic support are currently mostly prepared and maintained by the electroplating method for the surface corrosion-resistant layer. Due to the low bonding strength of the coating, which is easy to crack and has a short service period, it often needs to be transported from the well for disassembly and maintenance, and the installation workload is large. , the cycle is long. Nowadays, intelligent technology is gradually promoted in the coal machinery industry, and the application of high-quality and long-service products is an inevitable trend to realize unmanned operation in the well, which puts forward higher requirements for the performance and service cycle of hydraulic support columns. The application of high-efficiency, high-quality and low-cost green manufacturing technology can improve market competitiveness and create long-term value growth for enterprises
Laser Solutions
• Ultra-high-speed laser cladding
It is used for the preparation of anti-corrosion coating on the surface of shaft parts such as hydraulic support piston rod, movable column, and middle cylinder; due to low heat input and small deformation, it has unique advantages in surface cladding of parts with large aspect ratios.
• Inner wall laser cladding
It is used for the preparation of anti-corrosion coating on the inner wall surface of the middle cylinder parts. It can replace the traditional arc copper melting process. It can also prepare stainless steel and copper alloy coatings on the inner wall surface according to the application requirements, so as to reduce the cost, or to quickly repair the damaged area of the inner surface. repair.
• Conventional laser cladding repair
It can be used for the remanufacturing of damaged parts, or the manufacture of functional coatings on the surface of new parts, such as laser cladding of wear-resistant layers on the surface of roadheader picks and wear-resistant strips on the surface of scrapers.
• Laser–arc composite heat source welding
It can replace the traditional arc welding method to perform high-efficiency and low-distortion welding of medium and thick-walled parts, such as the welding of the cylinder piston section of the hydraulic support, the welding of the body components of the hydraulic support, and the welding of the scraper. Aachen United Technology provides different laser manufacturing technologies from materials, processes, equipment, intelligent monitoring to production process specifications, and formulates technical services and long-term process technical support for the entire production chain.
Laser Application Case
• Ultra-high-speed laser cladding of hydraulic support columns
Ultra-high-speed laser cladding can perform laser cladding at an ultra-high linear speed of 20-200m/min. Compared with conventional laser cladding technology, it has higher efficiency, lower dilution rate, better coating performance and lower cost; more Good surface finish enables the subsequent process to complete processing only by surface grinding and polishing; low heat input and small deformation, which can be used for coating processing of parts with large aspect ratios. Aachen United Technology Co., Ltd. took the lead in applying this technology to the large-scale production of parts such as piston rods, movable columns, and middle cylinders in the coal machinery industry. The high-efficiency and rapid preparation of corrosion-resistant coatings with a thickness of 0.05-1mm, the hardness can reach HRC50 or more. Whether it is new product processing or old product maintenance, mature production line processing technology specifications have been formed.
• Laser cladding of the inner wall of the cylinder
The surface of the middle cylinder of the hydraulic support column is prone to rust on the inner wall and form pits due to the unqualified use of the emulsion or the long standing time after the well is lifted. At present, the more commonly used method is to use the arc melting copper technology to prepare the corrosion-resistant coating on the inner surface, which is characterized by high efficiency and large coating thickness, but the heat input is relatively large and the cost is high. The inner wall laser cladding technology can replace or expand the traditional arc copper melting process to a certain extent, and can be used for the cladding of smaller diameter parts. Because the laser cladding method can adjust the powder material more conveniently, it is convenient to quickly prepare copper alloy, stainless steel or other coatings with good anti-corrosion properties according to different requirements of service environment and cost. The inner wall cladding processing head of Aachen United Technology Co., Ltd. has high integration, good stability, mature technology and wide adaptability, and has always occupied an important position in the field of inner wall laser processing. The inner diameter of the applicable pipe fittings is as low as Ф33mm, and the extension length on one side is up to 3000mm, which is a high-level scale range that can be achieved by the laser cladding and repairing technology of the inner wall at home and abroad. The cladding surface of the inner wall of the middle cylinder is smooth, smooth and defect-free, which not only significantly reduces the amount of subsequent processing, but also has almost no influence on thermal deformation of the product, no need to reserve machining allowance, and greater freedom in the arrangement of product production processes.
• Laser cladding repair of picks
When the pick encounters the hard material in the coal seam during operation, the external compressive stress and shear stress on the tooth edge suddenly increase. When the strength limit of the pick is exceeded, the tooth edge will collapse. The tooth edge after chipping is damaged and dull, and the resistance on the tooth edge becomes larger, which leads to increased wear and accelerates the failure of the pick. The application of laser cladding technology to pick repair and remanufacturing can effectively improve the hardness and wear resistance of the pick surface and prolong the pick life. The single-layer cladding thickness of the laser cladding of the pick is 1-3mm, the hardness is HRC65, and there is no crack or hole defect. The high-quality wear-resistant coating protection effectively reduces the wear and fracture probability of the pick when it is working, and reduces the consumption of the pick; moreover, the protective effect of the coating makes the pick less likely to generate sparks during operation, which greatly improves the mining efficiency. Operation rate of coal machinery.
• Laser-arc composite heat source welding for medium cylinders
At present, the piston section of the middle cylinder is basically welded by traditional arc welding methods, such as CO2 gas shielded welding and submerged arc welding. The advantages are mature technology and low cost; the limitations are low production efficiency, welding cracks and deformation. Laser-arc hybrid heat source welding technology combines advanced laser welding methods with traditional arc welding methods to obtain high penetration and high adaptability welding effects. Using the high energy density of lasers, the bottom layer can be layered to a thickness of 7-8mm at a time. The penetration depth can significantly improve production efficiency, and can effectively suppress cracks and reduce welding deformation. Laser-arc composite heat source welding has been widely used in pipelines, rail transit, automobiles, heavy machinery and other fields, and also has immeasurable application potential in the coal machinery industry. Such as the piston section of the middle cylinder, the body of the hydraulic support, the scraper, etc.
