Types of heat treatment of S275ML alloy steel plate

Thermomechanically rolled weldable fine grain structural steel (steel for mechanical construction)
European grade steel plate: S275M, S275ML, S355M, S355ML, S420M, S420ML, S460M, S460ML. M means: -20℃; ML means: -50℃.

The heat treatment types of S275ML alloy steel plate are: normalizing specification: normalizing temperature is 850-900℃, and it is air-cooled. High temperature tempering specification: tempering temperature is 680-700℃, and it is air-cooled. Hot working specification: heating temperature 1150-1200℃, starting temperature 1130-1180℃, end temperature > 850℃, slow cooling when φ> 50mm. Induction quenching and tempering specifications: quenching temperature 900℃, tempering temperature 150-180℃, hardness 54-60HRC. Annealing specifications: annealing, furnace cooling to 400℃ air cooling. Specification for sub-temperature quenching and toughening treatment: quenching temperature 900℃, tempering temperature 560℃, hardness (37±1) HRC. And quenching and tempering specifications: preheating temperature 680-700℃, quenching temperature 840-880℃, oil cooling, tempering temperature 580℃, water cooling or oil cooling, hardness ≤ 217HBW.

The uses of S275ML alloy steel plate are: electric power, engineering, boiler, machinery, coal mine, auto parts and military industry.