What is S55C steel

S55C steel is a kind of special steel. It is colloquially called "medium carbon steel", which is iron with high carbon content. After processing, S55C steel can be directly heat treated.

S55C is equivalent to China's high quality carbon structural steel grade 55. Like 45# steel, it belongs to medium carbon steel with high quality. S55C material is killed steel made by EAF, open hearth or pure oxygen converter. Steel S55C has the characteristics of excellent processability and uniform microstructure. S55C steel is cheap and easy to process. It is suitable for surface hardening treatment such as high frequency quenching and flame quenching. The carbon content (mass fraction,%) of S55C steel is more than or equal to 0.4, it has excellent wear resistance, but its ductility is reduced, and it is easy to deform and crack after quenching. Therefore, quenching is very important, and it must be quenched after tempering to avoid temper brittleness. S55C steel is difficult to cut and needs to be spheroidized to improve its cutting performance. In principle, it is tempered to hardness of 19 - 22HRC to facilitate machining.

S55C executive standard: JIS G4051, equivalent steel grades are AISI 1050 / 1055, JIS S50C / S55C and DIN 1.1730.