Shot blasting is also the name of a mechanical surface treatment process, similar to sand blasting and shot blasting. Shot blasting is a cold treatment process, which is divided into shot blasting cleaning and shot blasting strengthening. As the name suggests, shot blasting cleaning is to remove impurities such as surface oxide to improve the appearance quality. Shot blasting strengthening is to use high-speed moving projectile (60-110m/s) flow to continuously impact the surface of the workpiece to be strengthened. The surface and surface layers of the target (0.10-0.85mm) are forced to undergo the following changes during cyclic deformation: 1. The microstructure was modified; 2. The non-uniform plasticized outer surface introduces residual compressive stress, and the inner surface produces residual tensile stress; 3. External surface roughness changes (RaRz). Impact: It can improve the fatigue fracture resistance of materials/parts, prevent fatigue failure, plastic deformation and brittle fracture, and improve fatigue life.
Principle of shot blasting process:
Shot blasting means that the shot material (steel shot) is thrown to the working surface at a high speed and a certain Angle by mechanical method, so that the shot particle has a high speed impact on the working surface. Under the combined action of the vacuum cleaner vacuum negative pressure and rebound force, the shot material circulates itself in the equipment. At the same time, the shot material and the impurities cleaned down are recovered respectively through the air cleaning effect of the supporting vacuum cleaner. And a technique that allows the pellets to continue to be recycled. The machine is equipped with a dust collector to achieve dust-free and pollution-free construction, which not only improves efficiency but also protects the environment. When the machine is operated, the pellet size and shape of the pellet are selected, and the walking speed of the equipment is adjusted and controlled to control the projectile flow rate of the pellet, so as to obtain different projectile intensity and obtain different surface treatment effects.
Technical requirements of shot blasting process:
By controlling and selecting the particle size and shape of the pellet, adjusting and setting the walking speed of the machine, controlling the projectile flow rate of the pellet, different projectile intensity and different surface treatment effect can be obtained. The shot blasting process and the shot blasting equipment control the surface condition after treatment through three parameters according to the different surface to be treated. Select the size and shape of the pellet; The travel speed of the equipment; The flow rate of pellets. The above three parameters cooperate with each other to obtain different treatment effects and ensure the ideal roughness of the surface after shot blasting. For example: using S330 steel shot, flow 10A, treatment of C50 concrete surface, can reach a roughness of 90; By treating the asphalt surface, the flooding layer can be removed and the roughness is 80. When handling steel plates, the cleanliness standard of SA3 can be reached.
Shot blasting is the method of cleaning, strengthening (shot blasting) or polishing the workpiece with a shot blasting machine, which is used in almost all industries that use metals, including aerospace, automotive, construction, casting, shipbuilding, railways and many other industries. There are two techniques: shot blasting or sand blasting.
The first: shot blasting machine:
1. The shot blasting machine converts the motor energy directly into the power abrasive energy by rotating the turbine impeller.
2, the capacity of each impeller from about 60 kg per minute to 1200 kg/minute.
3, to use these large quantities of accelerators, use a wheel mill, in which large parts or large areas of parts must be in some form of rust, descaling, deburring, peeling or cleaning.
4, Often, the method of transportation of the parts to be thrown will define the type of machine: from simple desktops to integrated fully automatic manipulators for a full range of automotive manufacturers, via roller conveyors and belt descaling systems.
The second: sand blasting machine:
1, the sand blasting machine can be used in the form of blower or blower, the blast medium is pneumatically accelerated by compressed air and projected to the components by the nozzle.
2, for special applications, a media-water mixture can be used, which is called wet sandblasting.
3, in air and wet sandblasting, the nozzle can be installed in a fixed position, or can be operated manually or by automatic nozzle operator or PLC programmed automation system.
4, the sandblasting task determines the choice of grinding media, in most cases can use any type of dry or free-running grinding media.
Post time: Jun-30-2023
