Provides overall plant design for steel smelting, rolling, casting, forging, and heat treatment, as well as solutions for the recycling of scrap metal such as steel, copper, and aluminum. The main products are medium frequency melting furnace, medium frequency heating furnace, waste steel, copper, aluminum secondary melting furnace, molten steel refining and rolling, open and closed cooling tower, medium and high frequency surface quenching equipment, steel production line and other complete production line equipment.