S235JR is a European standard non-alloy structural steel, that is, a carbon structural steel with a low carbon content, which is used for welding, bolting, and riveting structures.
The carbon content of carbon structural steel is about 0.05% to 0.70%, and individual can be as high as 0.90%. Carbon structural steel can be divided into ordinary carbon structural steel and high-quality carbon structural steel.
Carbon structural steel has many uses and is used in a large amount. It is mainly used in railways, bridges, various construction projects, manufacturing various metal components bearing static loads, and unimportant mechanical parts and general welding parts that do not require heat treatment.
S235JR structural steel has higher requirements on strength and low temperature (0℃) impact toughness. Therefore, in terms of component control, a low-C and low-P component control method is adopted.
Manganese partially dissolves with iron in steel to form solid solution (ferrite or austenite), and partially carbonizes and forms cementite with iron, which can strengthen ferrite and refine pearlite. The V of the steel grade forms carbides, nitrides or carbonitrides with C and N to produce fine-grain strengthening and precipitation strengthening, which can significantly improve the strength and impact toughness of the steel.
