What is the approximate hardness of Q355 steel?
In the hot-rolled state, it is approximately HB 140–180, and after quenching and tempering, it can reach HB 200–250, making it suitable for machining.
What are the fatigue properties of Q355?
Superior to Q235, it has strong resistance to alternating loads and is suitable for dynamic load structures such as cranes and bridges.
Which national standards does Q355 steel plate comply with?
Main standard: GB/T 1591-2018 "Low Alloy High Strength Structural Steel"; Through-the-thickness properties: GB/T 5313-2010; Dimensions and shape: GB/T 709.
What are the common delivery conditions for Q355 steel plates?
AR (Hot Rolled): Most commonly used, low cost;
N (Normalized): Air-cooled at 900–920℃, refines grain size and improves low-temperature toughness;
M (Controlled Rolling): Controlled rolling, achieving a balance between strength and toughness;
QT (Quenched and Tempered): Quenching + tempering, used for applications requiring high strength and high toughness.
What is the common thickness range for Q355 steel plates?
Standard: 3–200mm; Extra-thick plates up to 400mm (custom orders required).