According to GB/T133, 2-2008, non-alloy steel is divide […]
According to GB/T133, 2-2008, non-alloy steel is divided into ordinary quality non-alloy steel, high-quality non-alloy steel and special quality non-alloy steel according to the main quality grade; low alloy steel quality grade is divided into ordinary quality low alloy steel, High quality low alloy steel and special quality low alloy steel; alloy steel is divided into high quality alloy steel and special quality alloy steel according to quality grade.
Non-alloy steel. Ordinary quality non-alloy steel refers to the steel that is not specified in the production process, such as color-coated plate, color steel plate, color-coated coil, and color steel coil, which requires special control quality. The quality grade of ordinary quality non-alloy steel (carbon structural steel) is divided into A, B, C, D, whether to do the rush test and under what conditions to do the impact test. Eight grades; do not do the impulse test, only the conventional tension and cold bend test; B grade: live at normal temperature (20 degrees Celsius) for impact test, impact work is 27J: C grade: impact test at 0 degrees Celsius, impact power 2J; Class D: Impact test at -27 degrees Celsius, impact energy is 27J. The B, C, and D impact patterns are V-notch longitudinal impact.
High-quality non-alloy steel refers to the special quality control of aluminum-zinc plating in the production process of color-coated plates, color steel plates, color-coated rolls and color steel coils (such as appearance, reduction of sulfur, phosphorus content, improvement of surface weight or increase of process control, etc.) ), in order to achieve special quality requirements than ordinary quality non-alloyed steel (such as good resistance to brittle fracture, good cold formability, etc.), but its production control is not as strict as special quality non-alloy steel (such as not controlling the hardened parts) .