Generally, the materials including steel, cast iron, Tungsten carbide sandblasting nozzle are produced. At present, most factories use steel spray nozzles, and a few are made of ceramic sand jet nozzles, but these two shotcrete nozzles have short service life and are not ideal. Under the action of high speed sand, the inner hole gradually wears out or becomes a flared mouth, which can not be used continuously. Hard alloy sandblast nozzle, also known as tungsten steel shotcrete. Hard alloy sandblasting nozzles with high hardness, high strength, corrosion resistance, high temperature resistant and low expansion coefficient, and a series of excellent features, at the same time, the wear-resisting performance is good, service life is long, compared with the steel sand blasting nozzle, 20 ~ 25 times can be improved.

Sand blasting is the motive force of compressed air or abrasive pump, which can be sprayed on the surface of parts by spraying gun to achieve the purpose of cleaning and finishing. Currently, sandblasting technology is widely used in machinery, petroleum, chemical industry, automobile, ship, aerospace, metallurgy, glass, coal and other industries. Sand blasting nozzle is the main wear resistant components in the sandblasting equipment, with a variety of dry or wet sand blasting machine, surface strengthening, surface cleaning, surface coating, surface modification and jet cutting one of the key components of machinery and equipment. Hard alloy sandblasting nozzles with high strength and toughness, good thermal conductivity, the hardness of cemented carbide is higher than the metal material, hard alloy sandblasting nozzle erosion rate is smaller than metal material, the erosion resistance higher than metal sand blasting nozzle, is the ideal choice of the blasting nozzle material.

The failure mode of the hard alloy sandblast nozzle.

Erosion wear is main failure form of tungsten carbide sandblasting nozzle, it refers to a solid surface with liquid containing solid particles, the contact of relative movement, the loss of the surface material, with solid particles of fluid can be high speed air flow, also can be fluid flow, the former produce spray sand erosion, the latter is called type slurry erosion. Hard alloy sandblasting nozzles wear belongs to the low Angle of erosion (15 or less) of erosion wear. The effect of erosion and wear behavior of many factors such as environment parameters (such as the Angle of attack, the erosion speed, the erosion of time and temperature, etc.), abrasive performance (such as hardness, particle size and shape, etc.), the performance of target (such as hardness, fracture toughness and microstructure structure, etc.

Structure classification of tungsten carbide sandblast nozzle.

1. Straight hole tungsten carbide sandblasting nozzle. Its internal structure is only the contraction section and the straight section, the structure is simple, easy to make. This type of nozzle cannot overcome the eddy current phenomenon in the inlet side, the pressure loss is large, and the abrasive outlet speed is less than 100m/s under the pressure condition of 0.7mpa. Generally used in small sandblasting equipment.

2. Venturi carbide sandblast nozzle. The structure of venturi nozzle is divided into three parts: contraction section, flat section and diffusion section. The working efficiency is 15% to 40% higher than the straight hole nozzle, and the abrasive consumption is reduced by 20%.

3. Double vented carbide sandblast nozzle. It is composed of two nozzles before and after, and the area of sandblasted area is 35% larger than that of the standard wenner nozzle, and the outlet speed of sandblasting medium is reduced. This nozzle is usually used for surface treatment of large areas of moderate strength.

4. Angle hard alloy sandblasting nozzle. Make the movement direction of the abrasive flow changes, can be used to clean the Bridges, towers and other steel structure truss, the pipe inner surface, makes it hard for the cleaning of parts can be directly hit by abrasive, achieve the purpose of cleaning.

Application of tungsten carbide sandblast nozzle.

Tungsten carbide shotcrete nozzles are mainly used for oil drilling, aircraft, ship, automobile, bridge, construction engineering, railway and other fields of coating engineering and surface treatment. Sand blasting can be divided into dry sandblasting and wet sand blasting. Its sand grains are quartz sand, carborundum and river sand, among which quartz sand application is the most common. Hard alloy sandblasting nozzles are cleaning, decontamination products, mainly used in ships, Bridges, water conservancy, machinery, chemical industry, container, pipe and other large equipment and parts surface sand blasting, rust removal, decontamination treatment. The hard alloy sandblast nozzle has the characteristics of high strength, high hardness and high wear resistance. The hardness (HRA) of hard alloy sandblasting nozzle (HRA) is 89-93, with a density of 14.4-15g/cm3, and the bending strength is not less than 1500Mpa. Hard alloy is the most widely used nozzle material. Its wearability is obviously better than alumina ceramics, and it can be used for hundreds of hours and is widely used in various structure sandblasting nozzles.

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