The industries that use DD12 and DX52 steel grades for industrial applications include automotive, construction, manufacturing, and engineering. These steel grades are commonly used for components and structures that require high strength, durability, and corrosion resistance. Some specific applications may include automotive body parts, construction beams, storage tanks, and machinery components. However, the specific usage areas can vary depending on the requirements of each industry and the specific properties of the steel grades. It is important to consult the relevant specifications and standards for each steel grade to determine their suitability for a particular application.