Application of Plasma Surfacing Technology in Coal Mining Machinery Industry

       my country's coal mining industry is one of the pillar industries of the national economy. It also consumes a large amount of resources while producing energy. How to improve the utilization rate of resources, prolong the service period of equipment and reuse of scrapped equipment is the direct economic benefit of the coal mining industry. It is important to increase social benefits. Because coal mine machinery and equipment are operated underground, the production environment is relatively harsh, equipment failures occur frequently, and the space for maintenance is small, many of which cannot be replaced and repaired underground, which virtually increases the maintenance difficulty of machinery and equipment, and then Affecting the smooth production of coal mines, the central trough, which is widely used, is a typical example. Therefore, it is of special significance to use plasma surfacing remanufacturing technology in the coal mining industry to improve the surface performance of wearing parts and prolong the service life.



1. Middle slot of scraper conveyor



The middle trough is mainly used for scraper conveyors and transfer machines in coal mines. During the use of the middle groove, the scraper and chain are scratched and the abrasive particles of coal are worn, and the surface without wear-resistant treatment is easily worn into pits and fails. The use of the middle tank is large and the maintenance volume is large, which is a prominent problem to be solved. The implementation of remanufacturing in the maintenance will produce obvious economic benefits.



The use of powder plasma surfacing technology is the best process for repairing the middle groove of the scraper conveyor.



Powder plasma surfacing is an advanced technology of surface cladding alloy using argon plasma arc as high temperature heat source and alloy powder as filler metal. It is one of the new surface hardening methods and has the following characteristics:



(1). High productivity.



(2). The quality and process stability of the surfacing layer are good.



(3). The surfacing process is pollution-free and automatic, realizing mechanized and automatic operation and reducing labor intensity.

CNC plasma surfacing is used for high-carbon and high-chromium alloys, the hardness of the surfacing layer is greater than HRC58, and there are a large number of chromium carbide hard phases in the surfacing layer, so it has excellent wear resistance. After treatment, the service life will be increased by 3-5 times.

2. Hydraulic prop plunger



The hydraulic prop is the most used equipment in the mine. As an important part of the whole machine, the hydraulic cylinder plunger is subject to environmental corrosion and scratches during operation. The plunger of the hydraulic prop used in the mine was chrome-plated before. , Because the chrome layer is very thin, the anti-corrosion and scratch resistance properties are very poor, and the service life is short, generally only 2-3 years. Due to the serious environmental pollution caused by chrome plating, it has been banned. At present, the laser cladding process is used to repair the hydraulic prop. Although this process is good, the equipment is expensive, the maintenance is complicated, and the operating cost remains high.



Plasma surfacing method is used to weld wear-resistant alloy on the surface of the plunger, which has a series of advantages such as high production efficiency, low operating cost, stable process, and easy control. It is an ideal method to replace electroplating, and the equipment investment is much lower than that of laser melting. The machine has outstanding advantages.

3. Pick



The pick is a wearing part that is widely used in mining equipment. Welding the wear-resistant belt on the pick body near the carbide head is an effective measure to improve the service life.



The use of powder plasma surfacing technology to strengthen the pick wear belt is the best process to improve the life of the pick. The pick plasma welding machine adopts an integrated structure, and the entire plasma welding process is highly integrated in the control system, which fully realizes fool-like operation and has high production efficiency.

4. Repair of wearing parts such as screw rod and drill pipe



In mine operation equipment, the working surfaces of various screws, drill pipes, shafts, sprockets, reducers, pumps, fans and other operating machinery will cause out-of-tolerance fit or surface failure due to wear and corrosion. Remanufacturing using plasma surfacing surface strengthening repair method can save costs, shorten the maintenance cycle, and give full play to the potential of existing resources