Which One Is Better,A Mobile Or A Pass-Through Steel Plate Shot Blasting Machine?

A shot blasting machine refers to a casting device that uses high-speed projectiles to clean or enhance the surface of castings. Shot blasting machines can simultaneously remove sand and cores from castings. In some regions, they are also known as sandblasting machines or shot peening machines. Shot blasting is a surface treatment technique that involves the high-speed projection of steel shot or steel grit to impact the surface of material objects. Compared to other surface treatment methods, it is faster, more effective, and can retain or improve certain surface features.

In the 1930s, the first shot blasting machine was manufactured by an American company and introduced to the world. The production of shot blasting equipment began in the 1950s, primarily following technology developed in the former Soviet Union. Shot blasting machines are used for various purposes, including the removal of burrs, membranes, and rust, which can affect the integrity, appearance, or definition of objects. They can also remove contaminants from the surface of coatings and provide a surface profile that enhances coating adhesion.

Shot blasting equipment was initially used to remove adhering sand and scale from the surfaces of cast steel and cast iron components in the foundry industry. Nearly all cast steel parts, gray iron castings, malleable iron castings, ductile iron castings, etc., undergo shot blasting. This process is essential not only for removing oxide layers and adhering sand from the surfaces of castings but also as a necessary preparation step for quality inspection of castings. For example, rigorous cleaning of large gas turbine casings is necessary before non-destructive testing to ensure reliable test results. In general foundry production, shot blasting is a necessary process to detect surface defects such as subsurface pores, slag inclusions, adhering sand, cold laps, and peeling.

The surface cleaning of non-ferrous metal castings, such as aluminum alloys and copper alloys, serves the main purpose of removing flash and achieving decorative surface quality and overall effect. In the production of metallurgical steel, shot blasting or pickling is a combined mechanical or chemical process to remove phosphorus scale, ensuring high productivity for large quantities of steel. When producing alloy steel plates such as silicon steel and stainless steel plates, shot blasting or pickling is performed after annealing in the cold rolling process to ensure surface roughness and thickness accuracy of the cold-rolled steel plates.

Shot blasting is a process that utilizes high-speed rotating impellers to propel small steel or iron shots at a high velocity, impacting the surface of components. This effectively removes the oxide layer from the surface of the parts. Additionally, the high-speed impact of steel or iron shots on the surface of components causes distortion and deformation of the crystal lattice, resulting in increased surface hardness. This method is used for cleaning and strengthening the surface of components, often employed in the cleaning of castings or for surface enhancement treatments.

Generally, shot blasting is suitable for regular-shaped objects, where multiple shot heads work simultaneously from different directions, offering high efficiency and minimal pollution. Industries like shipbuilding and repair commonly employ shot blasting and sandblasting. Both shot blasting and sandblasting use compressed air, but not all shot blasting processes require high-speed rotating impellers.

In the shipbuilding and repair industry, shot blasting (using small steel shots) is often used for steel plate pre-treatment (rust removal before painting), while sandblasting (using mineral sand) is more common for the treatment of formed ships or sections. Sandblasting removes old paint and rust from steel plates before recoating. In shipbuilding and repair, the main purpose of shot blasting and sandblasting is to enhance the adhesion of paint coatings to steel plates.

For cleaning castings, more than just shot blasting is typically employed. For large components, a common practice is to start with drum cleaning. This involves placing the castings in a rotating drum, where the components collide with each other, effectively removing most of the surface sand. Afterward, shot blasting or sandblasting is carried out. The size of shot blasting pellets is typically around 1.5mm.

Research has shown that, in terms of material damage, surfaces with tensile stresses are much more susceptible to damage than those under compressive stresses. When the surface is subjected to compressive stresses, the fatigue life of the material significantly increases. Therefore, for components prone to fatigue fractures, such as shafts, shot blasting is often used to induce compressive surface stresses, improving product lifespan. Additionally, metal materials are more sensitive to tensile stresses, which is why tensile strength (yield strength, tensile strength) is commonly used to represent material properties, as opposed to compressive strength.

The working surfaces of the steel plates in the automobiles we commonly use are strengthened using shot blasting, which significantly improves the material’s fatigue resistance.

Shot blasting is a process where an electric motor drives a wheel to rotate, and by the action of centrifugal force, pellets (ranging in diameter from 0.2 to 3.0 mm, including cast pellets, cut pellets, stainless steel pellets, etc.) are propelled onto the surface of the workpiece. This process achieves a certain level of surface roughness on the workpiece, making it aesthetically pleasing or altering the tensile stress on the workpiece into compressive stress, thereby improving the workpiece’s lifespan. Shot blasting is applied in nearly all mechanical fields, including shipbuilding, automotive components, aircraft parts, firearms, tanks, bridges, steel structures, fiberglass plates, pipelines, and more. Sandblasting (or shot peening) employs compressed air to propel sand with a diameter between 40 and 120 mesh or pellets with a diameter around 0.1 to 2.0 mm onto the surface of the workpiece, achieving similar effects. The size of the pellets or sand grains influences the treatment outcome. It’s important to emphasize that sandblasting can also have a strengthening effect.

Currently, some domestic equipment in China is under the misconception that only shot blasting can achieve the purpose of strengthening. In contrast, American and Japanese companies use both shot blasting and sandblasting for strengthening, each with its advantages. For example, for workpieces like gears, the angle of pellet ejection in shot blasting cannot be changed and can only be adjusted using variable frequency to alter the initial velocity. However, it can handle large quantities and is fast, whereas sandblasting is the opposite, with shot blasting having a better overall effect.

Sandblasting is a method that uses compressed air to propel quartz sand at high speeds to clean the surface of components. It is also known as “blasting” in factories. Sandblasting not only removes rust but can also remove oil, making it highly useful for painting applications. It is commonly used for rust removal from the surface of components, surface modification (small wet sandblasting machines available in the market use alumina as the abrasive material, with water as the medium), and in steel structures. The application of high-strength bolts for connections is an advanced method that relies on friction between mating surfaces to transmit force. Therefore, the quality of mating surfaces is crucial, and sandblasting is necessary to treat these surfaces.

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