Application of plasma cladding technology on screw

        The application of plasma cladding technology on screws is mainly to improve the wear resistance, corrosion resistance and erosion resistance of screws and extend their service life. Screws are widely used in petrochemical, plastic machinery, pharmaceutical and other fields, and are often in high wear and high corrosion working environments. Therefore, the performance of their surface has an important influence on the overall use effect of the screw.

Screw surface problems and surfacing requirements

The screw is affected by the following problems during operation:

Wear : When the screw is in contact with materials or fluids for a long time, especially when it contains solid particles or corrosive media, the wear on the screw surface will be aggravated, resulting in a decrease in the dimensional accuracy of the screw and affecting work efficiency.

Corrosion : When handling corrosive materials such as acid and alkaline, the surface of the screw is easily corroded, which in turn affects its service life.

High temperature working conditions : Under high temperature conditions, the strength and hardness of the screw surface will decrease, resulting in increased peeling or wear of the surface material.

Advantages of plasma cladding technology

Plasma cladding technology is very suitable for surface repair and strengthening of screws due to its high temperature, precise heat input and low heat affected zone. Its main advantages include:

High wear resistance : Plasma cladding can use extremely hard alloy materials, such as cobalt-based, nickel-based, iron-based or carbide-reinforced alloys, to significantly improve the wear resistance of the screw surface.

Corrosion resistance : The use of corrosion-resistant alloys (such as nickel-based alloys) can enhance the corrosion resistance of the screw in acidic and alkaline environments.

Metallurgical bonding : A metallurgical bond is formed between the cladding material and the base material, ensuring good bonding strength and preventing the surface coating from peeling off.

Low heat affected zone : The heat affected zone produced by plasma cladding is small, which avoids deformation of the screw base material and ensures dimensional accuracy.

Screw plasma surfacing process steps

Surface preparation : Before screw cladding, the screw surface needs to be cleaned and polished to remove grease, oxides and other contaminants to ensure that the surface is clean and smooth and ready for cladding.

Select surfacing materials : Select suitable surfacing materials according to the working environment of the screw. Commonly used materials include cobalt-based alloys, nickel-based alloys or carbide-reinforced alloys.

Powder feeding rate : Control the powder feeding rate to ensure uniform thickness of the cladding layer and avoid over-thick or over-thin cladding layers.
Welding speed : Ensure that the welding speed is moderate to prevent overheating or cooling too quickly, which will affect the quality of the cladding layer.

Overlay welding process : Through the high temperature of plasma arc, the overlay welding material is melted and combined with the screw surface to form a high hardness and high wear resistance overlay welding layer. Overlay welding can adopt multi-layer process to ensure the required thickness and performance.

Cooling and post-processing : After surfacing is completed, the screw needs to be cooled slowly to avoid cracking of the surfacing layer due to rapid cooling. After cooling, the surfacing surface needs to be machined or polished to ensure surface finish and dimensional accuracy.

Application fields of screw plasma cladding

Plastic extruder screw : The screw of the plastic extruder works under high temperature and high wear conditions for a long time. Overlay welding of cobalt-based alloy or carbide-reinforced alloy can improve its wear resistance and extend the service life of the screw.

Oil drilling screw : Oil drilling screw is in a high wear and corrosion environment. The use of nickel-based or cobalt-based alloy surfacing can significantly improve the wear resistance and corrosion resistance of the screw.

Food and pharmaceutical machinery screws : These screws have high requirements for corrosion resistance and are clad with nickel-based alloys to effectively prevent corrosion and ensure product quality.

Summary of the advantages of plasma cladding technology

Improve wear resistance and corrosion resistance : The surfacing material has excellent wear resistance and corrosion resistance, which can effectively extend the service life of the screw.

Efficient repair : For worn or corroded screws, plasma cladding can efficiently repair and restore their original performance, avoiding the need to replace the entire screw.

Reduce maintenance costs : Through surfacing welding repair, the need for frequent screw replacement is reduced, reducing the company's operating costs.

The application of plasma surfacing technology in screw surface strengthening can not only greatly improve the service life of the screw, but also optimize its performance under high wear and high corrosion conditions. It is an effective way to improve the durability of the screw.