Ceramic Roller

The supersonic spraying of tungsten carbide on boiler tube is an advanced surface treatment technology applied to the protection of boiler tube, which aims to improve the wear resistance, corrosion resistance and high temperature resistance of boiler tube, thereby extending its service life and ensuring the stable operation of boiler. Here are the details for you:

One: the role of the boiler tube

1, improve anti-erosion ability: When the boiler is running, the high-temperature flue gas carries a lot of dust, fly ash and other particulate matter, and washes the surface of the boiler tube at a higher speed. After the treatment of supersonic spraying tungsten carbide, the wear resistance of the boiler tube surface is greatly improved, which can effectively reduce the wear caused by particle erosion, reduce the risk of tube wall thinning, and ensure the long-term safe operation of the boiler.

2, enhance the oxidation resistance: in the high temperature environment, the boiler tube is prone to oxidation reaction, resulting in a decline in the performance of metal materials. Tungsten carbide coating can form a dense protective film on the surface of the boiler tube, prevent the contact between oxygen and the base metal, slow down the oxidation rate, and improve the oxidation resistance of the boiler tube.

Two: Key points of construction technology

1, surface pretreatment: Before spraying tungsten carbide coating, the boiler tube surface must be strictly pretreated. First of all, the oil, rust, oxide and other impurities on the surface should be thoroughly removed, and then sandblasting should be carried out to form a certain roughness on the surface to increase the binding force between the coating and the substrate.

2, spraying parameters control: In the spraying process, it is necessary to accurately control the distance, Angle, moving speed, gas flow, powder delivery and other parameters. The appropriate parameter Settings can ensure that the tungsten carbide powder is evenly sprayed on the boiler tube surface to form a good quality coating. Generally speaking, the distance between the spray gun and the workpiece surface is maintained between 150-300mm, and the moving speed is about 5-10m /min.

3, coating post-treatment: After spraying is completed, it is sometimes necessary to carry out appropriate post-treatment of the coating, such as heat treatment, grinding, etc. Heat treatment can further improve the bonding strength and hardness of the coating. Grinding can improve the flatness of the coating surface and meet some conditions that require high surface finish.

Three: Application cases

Because the boiler of a large thermal power plant is in a bad operating environment for a long time, the problem of boiler tube wear and corrosion is serious, and the tube explosion accident frequently occurs, which affects the normal power generation of the power plant. Later, some boiler tubes were protected by supersonic spraying tungsten carbide technology. After a period of operation monitoring, it was found that the wear rate of boiler tubes after treatment with this technology was significantly reduced, the corrosion was effectively suppressed, and the number of tube bursts was significantly reduced, which greatly improved the operational reliability of the boiler and reduced maintenance costs and downtime.