Definition of sandblasting, shot blasting, and shot peening
Sandblasting is the use of compressed air as the power to form a high-speed jet beam to spray material (copper ore, quartz sand, diamond sand, iron sand, Hainan sand) high-speed spray to the surface of the workpiece to be treated so that the appearance of the workpiece surface or shape changes, due to the impact of abrasive on the surface of the workpiece and cutting effect, so that the surface of the workpiece to obtain a certain degree of cleanliness and different roughness, so that the mechanical properties of the workpiece surface are improved, so it improves the fatigue resistance of the workpiece, increases the adhesion between it and the coating, prolongs the durability of the coating film, and also facilitates the leveling and decoration of the coating.
The principle of shot blasting is to use an electric motor to drive the impeller body rotation (direct drive or V-belt drive) by the role of centrifugal force, the diameter of about 0.2 ~ 3.0 projectile (there are different types of cast steel shot, steel wire cut shot, stainless steel shot, etc.) to the surface of the workpiece, so that the surface of the workpiece to achieve a certain degree of roughness, so that the workpiece becomes beautiful, or change the workpiece welding tensile stress to compressive stress, improve the workpiece life. Improving the roughness of the workpiece surface also improves the paint film’s adhesion for the subsequent painting of the workpiece. The implication is that the shot blasting process can be a pre-process for the painting process.
Shot peening. The surface treatment by shot peening has a high striking force and an obvious cleaning effect. But shot peening on a thin plate workpiece, easy to make the workpiece deform. Steel shot striking the surface of the workpiece (whether shot peening or shot peening) to make the metal substrate deformation due to Fe3O4 and Fe2O3 no plasticity, broken peeling, and the oil film with the substrate deformation, so the workpiece with oil, shot peening, shot peening can not completely remove the oil. In the existing workpiece surface treatment methods, the best cleaning effect is also sandblasting cleaning. Sandblasting is suitable for the workpiece surface requirements of high cleaning. But China’s current general sandblasting equipment by the hinged dragon, scraper, bucket elevator, and other original heavy sand transport machinery.
Sandblasting shot blasting, shot blasting characteristics
The characteristics of sandblasting
1, sandblasting treatment is the most thorough, the most versatile, the most rapid, and the most efficient cleaning method.
2, sandblasting treatment can be in different roughness between any choice, while other processes cannot achieve this. Manual sanding can hit the rough surface, but the speed is too slow, chemical solvent cleaning is too smooth cleaning the surface is not conducive to coating bonding.
The characteristics of shot peening
1, the flexibility of cleaning. It is easy to clean the internal and external surfaces of complex workpieces and the pipe’s inner wall; and is not limited by the site; it can be moved to a very large workpiece near the cleaning.
2、Simple structure of the equipment, less investment in the whole machine, fewer wearing parts, low maintenance costs.
3, energy consumption, must be equipped with a high-powered air pressure station
4、Cleaning surface is easy to have moisture, easy to rust.
5, low cleaning efficiency, operators, and labor intensity.
The characteristics of shot blasting
1, poor flexibility. Restricted by the site, clean up the workpiece some blindness; the surface of the workpiece within the guard is prone to clean up the dead ends
2, without compressed air to accelerate the projectile, without having to set up a high-powered air pressure station.
3, cleaning the surface is not easy to have moisture not easy to rust.
4, the structure of the equipment is more complex, with more worn parts, especially the blade and other parts, maintenance time, and high cost.
5、High cleaning efficiency, low cost, fewer operators, easy to achieve automatic control, suitable for mass production, and the cost of cleaning.
Sandblasting, shot blasting and shot blasting uses
1.Workpiece surface cleaning
It can be used for the metal rust layer, heat treatment of the surface of the residual salt and oxidation layer, rolling parts surface oxidation layer, forging parts surface oxidation layer, welding parts surface oxidation layer, castings surface sand and oxidation layer; machine parts surface residual dirt and tiny burrs, old machine parts surface treatment, to remove the surface adhesion layer, reveal the original color of the substrate, surface cleaning quality can reach Sa3 level.
2. Pretreatment of workpiece surface before coating
It can be used as the pretreatment process of various plating processes, brushing, spraying, and bonding processes to obtain an active surface and improve the adhesion between plating, coating, and bonding parts.
3 ． Change the physical and mechanical properties of the workpiece
It can change the workpiece’s surface stress state, improve the mating coupling’s lubrication condition, and reduce the noise during the movement of the coupling. It can make the surface of the workpiece harden and improve the parts’ wear resistance and fatigue strength.
4 ． Workpiece surface finishing process
It can change the surface roughness Ra value of the workpiece. It can produce a matte or diffuse reflection of the workpiece surface to achieve the purpose of finishing processing.
Shot peening technology is widely used in machining, welding, and casting manufacturing fields, but also widely used in the ship, automotive, aviation, and other industries. The application of shot peening has been extended from the traditional titanium alloy and aluminum alloy parts to magnesium alloy, powder metallurgy, and other new materials, and shot peening is used to improve its fatigue life and to make its plastic deformation, to achieve surface nanosized. Shot peening of ZK60 magnesium alloy and CW103K new high-strength magnesium rare earth alloy can improve fatigue performance and fracture behavior. The key equipment has been developed to support them. Shot peening of the metal mixed powder coating with self-propagation reaction occurred, and the nano surface coating was obtained.
It can remove the cast steel, cast iron surface oxidation, or sticky sand; the surface of the casting plays a role in cleaning, but also the quality of the casting of a necessary step in the inspection, the large turbine casing to go before the line of shot blasting before flaw detection, to ensure a reliable result. Hanger type shot blasting machine is divided into a single hook and double hook, hanger type shot blasting machine by two hooks loaded with workpieces alternately into the blast cleaning room. The use of a shot blasting machine will be 0.2 ~ 0.8 of the projectile to the workpiece’s surface so that the workpiece’s surface achieves a certain degree of roughness so that the workpiece becomes beautiful or change the compressive stress of the workpiece to improve life.
The difference between sandblasting, shot blasting, and shot blasting
The difference between shot blasting and shot peening
Shot blasting uses high-pressure wind or compressed air for power, while shot blasting is generally a high-speed rotating flywheel to throw the steel sand out at high speed. Shot blasting is efficient, but there will be dead space, while shot blasting is more flexible, but the power consumption is large.
Although the two processes are different in the power and way of blasting, both are a high-speed impact on the workpiece for the purpose; the effect is the same; in comparison, blasting is finer and easy to control the accuracy, but the efficiency is not as high as the shot blasting, suitable for complex shapes of small workpieces, shot blasting is more economical and practical, easy to control the efficiency and cost, you can control the particle size of the shot to control the effect of blasting, but there will be dead space, suitable for the shape of a single workpiece. Batch processing.
The choice of the two processes depends mainly on the shape of the workpiece and the processing efficiency.
Shot blasting and sandblasting difference
1.Shot blasting and sandblasting use high-pressure wind or compressed air for power, which will be blown out at high speed to impact the surface of the workpiece to achieve the cleaning effect, but the choice of media is different; the effect is not the same. Sandblasting media is required to have a good cutting effect; shot blasting media is required to be as spherical as possible and does not allow the existence of sharp angles.
2.After sandblasting, the surface dirt is removed from the workpiece, the surface of the workpiece is slightly damaged, and the surface area is greatly increased, thus increasing the bonding strength of the workpiece and the coating/plating layer.
After sandblasting, the surface of the workpiece is metallic, but because the surface is rough, the light is refracted away, so there is no metallic luster, and the surface is dark.
3.After blasting, the surface dirt is removed from the workpiece, the surface of the workpiece is not easily damaged, and the surface area increases. Since the surface of the workpiece is not destroyed during processing, the excess energy generated during processing will trigger the surface strengthening of the workpiece substrate.
The surface of the workpiece after shot blasting is also the original color of the metal. Still, because the surface is spherical, the light is partially refracted away, so the workpiece is processed for a matte effect.
4.Sandblasting is suitable for plastic, glass, and metal; shot blasting is suitable for metal products.
The difference between shot blasting and sandblasting
Whether it is shot blasting or sandblasting, both can be used in the form of compressed air. Of course, using a high-speed rotating impeller for shot blasting is unnecessary. In the repair and shipbuilding industry, generally speaking, shot blasting (small steel shot) is mostly used in steel plate pretreatment (rust removal before painting); sandblasting (repair and shipbuilding industry with mineral sand) is mostly used in the forming of ships or segments, the role is to remove the old paint and rust on the steel plate, re-painting. In the repair and shipbuilding industry, the main function of shot blasting and sandblasting is to increase the adhesion of painted steel plates.
The casting parts are cleaning not only with shot blasting, for large pieces of general first roller sand cleaning, is the casting parts of the riser mouth are removed and placed in the roller roll by the parts in the roller collision with each other, the surface of the sand most of the first clear away before shot blasting or shot blasting.
Shot blasting and sandblasting can play a cleaning and decontamination of the workpiece, the purpose of the next sequence for the preparation, that is, to ensure the roughness of the next process requirements, but also to ensure the consistency of the surface; shot blasting on the workpiece has a strengthening effect, sandblasting is not obvious. General shot blasting for small steel balls and sandblasting for quartz sand. According to different requirements, the number of subheads is. Precision casting almost every day with the process of sandblasting and shot blasting.
Looking for a supplier for your die-casting project?
V1 Die Casting is a leading supplier of die-casting services. It’s important to work with the right manufacturing partner! We have a team of highly skilled engineers to provide you with professional industry experience. Send us a message today, and we will get back to you as soon as possible.