1. Surface cleaning of various castings
Shot blasting equipment is first used to remove sand and oxide scale on the surface of steel and iron castings. Almost all steel castings, gray iron castings, malleable cast iron castings, ductile iron castings, etc. need to be shot blasted. This is not only to remove the oxide scale and sand on the surface of the castings, but also an indispensable preparation process before the quality inspection of the castings. The casing of large steam turbines must be strictly shot blasted before non-destructive testing to ensure the reliability of the flaw detection results. In general casting production, shot blasting is an indispensable process to find surface defects of castings, such as subcutaneous pores, slag holes, sand, cold shut, peeling, etc. The surface cleaning of non-ferrous metal castings, such as aluminum alloy castings and copper alloy castings, in addition to removing oxide scales and surface defects of castings, is more widely used to remove burrs of die castings and obtain decorative surface quality, as well as the comprehensive effect of strengthening structural parts.
2. Shot blasting of various forgings and heat-treated parts
Most metal workpieces will produce surface oxidation during forging heat treatment heating. This layer of oxide scale has a serious destructive effect on the chemical coating rust removal of parts and needs to be shot blasted. For parts that need to be cut, removing oxide scale is a necessary condition to increase the service life of cutting tools, maintain machine tool accuracy and control the size of forging blanks to obtain the best cutting state. This is even more important for automatic processing machine tools. Shot blasting of workpieces that have undergone final heat treatment can achieve a comprehensive effect of removing oxide scale and strengthening workpieces. Almost all gears of automobiles and tractors are shot blasted after heat treatment.
3. Process application in metallurgical steel production
In metallurgical steel production, shot blasting-pickling is the only process method for mechanical and chemical combined dephosphorization to ensure high productivity in mass production of steel. In the production of other alloy steel plates and strips such as silicon steel sheets and stainless steel sheets, annealing-shot blasting-pickling must be performed in the cold rolling process to ensure the surface roughness and thickness accuracy of the cold-rolled steel plates.
4. Surface shot blasting of steel plates, steel sections and steel structures
In heavy machinery, mining machinery, shipbuilding, vehicle manufacturing and various high and medium pressure containers and boiler manufacturing industries, in order to obtain the best surface quality and anti-rust function of the machine, its raw material steel plates and various industrial groove angle steels must be shot blasted and rust-removed-painted pretreatment. The important significance of removing the oxide scale on the metal surface in this pretreatment is: to provide good surface preparation for subsequent processes, especially CNC automatic gas cutting and various automatic welding, because the process quality of automatic gas cutting and automatic welding cannot be guaranteed when there is oxide scale on the metal surface.
In other cases, the steel structure is formed by stamping and welding. Before painting, the surface of the entire steel structure must be shot blasted and rust-removed. This type of shot blasting machine is generally large and dedicated and designed for the steel structure to be cleaned, such as the shot blasting cleaning of the entire train carriage and large containers.
The above mentioned are all aimed at removing the oxide scale on the metal surface. The shot blasting process mostly uses white cast iron shot or medium hardness cast steel shot, and the shape and particle size of the shot are not very strict. In order to obtain higher shot blasting efficiency, shot blasting of castings and forgings generally uses larger particle size shot, while shot blasting of stainless steel plates and silicon steel sheets in the production of metallurgical steel balls uses finer particle size shot.
Post time: Mar-28-2025