Supersonic flame spraying spray pipe

Abstract

The invention discloses a supersonic flame spraying spray pipe. The spray pipe is made of a molybdenum alloy material. The molybdenum alloy material includes 2-3 wt% of chromium, 8-9 wt% of nickel, 0-0.15 wt% of carbon, 0-2.5 wt% of iron, 0.4-0.9 wt% of manganese, 0.6-1 wt% of silicon, 0-0.01 wt% of boron, 0-0.02 wt% of phosphorus, 0-0.02 wt% of sulfur, and the balance molybdenum. The supersonic flame spraying spray pipe has long service life, can reduce the adhesion of a spraying powder in the spray pipe, and increases the available particle size range of the spraying powder.

Description

technical field [0001] The invention belongs to the technical field of supersonic flame spraying, and in particular relates to a spray pipe for supersonic flame spraying. Background technique [0002] High Velocity Oxygen Fuel (HVOF, High Velocity Oxygen Fuel), also known as supersonic flame spraying, is the use of acetylene, propane, propylene and other hydrocarbon gas or hydrogen, and kerosene, diesel and other liquid fuels and high-pressure oxygen in the combustion chamber or in the Combustion in a special nozzle, the burning flame generates high pressure in the combustion chamber and generates a high-temperature, high-speed combustion flame flow through the expansion nozzle connected to the outlet of the combustion chamber. A method of forming a coating on a substrate surface. [0003] The outlet design of the combustion chamber makes the high-speed airflow expand and accelerate sharply, forming a supersonic zone and a low-pressure zone. The powder is injected at multi...

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Problems solved by technology

[0005] Nozzles for supersonic flame spraying are usually made of red copper. Because red copper is soft and has poor wear resistance, the service life is short.

In addition, supersonic flame spraying requires high temperature to soften the powder particles, and obtains a high-density coating after hitting the surface of the object at high speed. The powder particle size is strictly controlled during the spraying process. Normally, powders within the particle size range of 15 to 45 μm are used, and the diameter is greater than Particles with a diameter of 45 μm cannot be softened, and cannot be deformed into a flat shape after impact, which will cause spraying failure or even scratch the nozzle; particles with a diameter of less than 15 μm will appear over-melted, and the powder after over-melting will become molten or semi-molten. Blocking the nozzle on the inner wall of the nozzle leads to the failure of normal spraying. This phenomenon is more prominent when encountering high-melting point metals. The current general solution is to reduce the particle size range of the powder and shorten the size of the gun barrel and increase the power for spraying, resulting in powder The powder output rate increases at low cost, and the fuel cost increases after the power is increased, causing a lot of unnecessary waste

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