Arc spraying and cladding technology
1. The anti-corrosion life is long, which is unmatched by other anti-corrosion methods. Once anti-corrosion, once and for all.
2. The localization of equipment and raw materials reaches 100%, and the process is simple and easy to implement. Compared with hot-dip galvanizing, arc spraying is flexible and convenient. A set of equipment can perform anti-corrosion construction on parts of different shapes and sizes, which is convenient for flow construction. The hot-dip galvanized anti-corrosion components of different sizes and shapes will be limited by the size of the molten pool, and it is inconvenient for flow construction.
3. Environmental protection. The use of special supporting and low-cost dust removal facilities makes the emissions meet the national environmental protection standards. However, there are no environmental protection measures for the rust removal acid solution for painting and hot-dip galvanizing and the zinc vapor generated by hot-dip galvanizing.
4. The equipment investment of arc spraying is only 1/5～1/15 of hot dip galvanizing, the investment of hot dip galvanizing equipment is about 1 to 3 million yuan, and the investment of arc spraying equipment (including dust removal equipment) is about 80% of the general production scale. -1 million yuan, and the mass production of extra-large components is about 1 to 1.5 million yuan.
5. In the process of processing, lifting, transportation, and installation of coal mine shaft steel structure, the coating is easily damaged and scratched, and the arc spraying technology itself can be repaired; while the hot-dip galvanizing itself cannot be repaired and can only be repaired by spraying. , It is bound to increase equipment investment again.
6. Arc spraying can spray corresponding corrosion-resistant material coatings according to different corrosive environments, and the process system has universal applicability. Hot-dip zinc can only prepare zinc coatings. For complex corrosive environments, a single zinc coating will be difficult to adapt, which will greatly reduce the corrosion life of the coating.
7. Compared with flame spraying, the binding force and production efficiency of arc spraying are more than twice that of flame spraying. The cost is low, the process is stable, and the construction is convenient.
(2) Features of arc spraying equipment
Arc spraying equipment has the characteristics of good spray coating quality, high density, strong bonding force, high spraying efficiency, high efficiency and energy saving, simple and safe operation, etc. It can spray zinc, aluminum, stainless steel, copper and other metal wire materials, and is used in various anti-corrosion projects And mechanical maintenance.
The equipment has the following notable features:
1. High spraying efficiency: this type of arc spraying equipment can spray 25-35kg of zinc per hour, which is the traditional wire flame spraying efficiency
2 to 4 times of that.
2. Good coating quality: This series of arc spraying equipment adopts the current world-recognized advanced technology-double atomization, closed nozzle, the sprayed atomized particles have high temperature, fast flying speed, dense and uniform coating, Physical properties (e.g. density,
Bonding strength) are better than traditional wire flame spray coating.
3. Convenient and safe operation: This series of arc spraying equipment is small in size and flexible to move; the weight of the spray gun is only 1 kg, which greatly reduces the labor intensity of the person, and the operation is very convenient; the output voltage of the equipment is below 40V, which is very safe.
4. The workpiece is not deformed during spraying: due to the high-pressure air as the power, the workpiece is slightly heated during spraying, which ensures
The workpiece is not deformed during spraying.
2. New development of radiator arc spraying technology
1. Droplet speed
High Velocity Arc Spraying Technology (HVAS) is an advanced thermal spraying technology developed in the 1990s. Because of its drastically improved droplet flying speed (up to 350m/s) and the further improvement of the atomization effect, it is prepared and plasma spraying Similar high-quality coatings with high bonding strength and low porosity greatly broaden the application fields of arc spraying.
The performance of arc sprayed coatings is affected by many factors, and its rapid solidification structure is closely related to the dynamics and heat transfer of the droplets during the atomization process. The analysis of the kinetics and heat transfer behavior of the atomization process is not only an important basis for selecting spraying process parameters, but also helps to correctly understand the formation and evolution mechanism of the high-velocity arc spray coating structure. However, due to the limitations of experimental technology, it is difficult to obtain heat transfer parameters such as droplet temperature and cooling rate with actual measurement methods. Theoretical models are usually used for numerical simulation calculations, and the determination of atomizing airflow velocity and droplet velocity is a prerequisite for simulation calculations.
2. Metal arc spraying
Metal spraying is the use of compressed gas to atomize molten metal into particles, which are sprayed and deposited on the surface of the workpiece prepared in advance.
On the surface, a complete metal covering layer is formed. Generally speaking, metal spraying has three main uses:
(1) It is used for protective coatings such as corrosion resistance, high temperature oxidation resistance or wear resistance;
(2) It is used to repair the size of the part, such as the geometric size of the component due to large-scale abrasion or local machining error
Insufficiency can be repaired by metal spraying;
(3) Use non-metallic materials sprayed with metal on the surface to replace metal manufacturing equipment or parts. Metal arc spraying is the use of AC or DC arc to melt the continuously fed metal spray wire, which is then atomized by compressed air through a nozzle and sprayed onto the surface of the workpiece. The main device of the spraying process is called a metal arc spray gun.