Carbon steel is not heat treated under normal circumstances, and in the supply of state directly. Usually Q195, Q215, Q235 mass fraction of low-carbon steel, welding performance, plasticity, toughness, a certain intensity, often rolled into a sheet, steel, welded steel pipes, etc., for bridges, buildings and other structures and production of common screws, nuts and other parts. Q255 and Q275 slightly higher mass fraction of carbon steel, high strength, ductility, toughness, can be welded, usually rolled into steel, strip steel and steel for structural parts and manufacturing simple mechanical linkage, gears, coupling section, marketing and other parts.
