Shot blasting equipment was first applied in the foundry industry for the removal of adhering sand and scale from the surfaces of cast steel and cast iron components.
Virtually all cast steel parts, as well as gray iron, malleable iron, and ductile iron castings, undergo shot blasting treatment. This serves not only to remove surface scale and adhering sand from the castings but also constitutes an indispensable preparatory step prior to quality inspection; for instance, the casings of large gas turbines must undergo rigorous shot blasting and cleaning before non-destructive testing to ensure the reliability of the inspection results. In general casting production, shot blasting is an essential process for detecting surface defects such as subsurface porosity, slag inclusions, adhering sand, cold shuts, and surface peeling. For non-ferrous metal castings-such as those made from aluminum or copper alloys-surface cleaning via shot blasting serves a primary purpose beyond merely removing scale and detecting defects: it is used to deburr die-cast parts and to achieve a surface finish with aesthetic appeal, thereby yielding a comprehensive result.
In metallurgical steel production, shot blasting-or pickling-is a process method involving a combined mechanical or chemical approach to remove mill scale, thereby ensuring high productivity in the mass production of steel. In the production of silicon steel sheets, stainless steel thin plates, and other alloy steel plates and strips, an annealing process must be performed during the cold rolling stage, followed by shot blasting or pickling, to ensure the required surface roughness and dimensional accuracy of the cold-rolled steel products.
