Q390A steel is a low-alloy high-strength structural steel. The executive standard of Q390A steel is GB/T9943-2008. Q390A low-alloy high-strength structural steel, referred to as high-tech steel or high-speed steel, commonly known as "front steel" or "wind steel", is a high-carbon high-low alloy high-strength structural steel suitable for high-speed cutting. The delivery state of Q390A steel is delivered in the state of hot rolling, controlled rolling, normalizing and normalizing plus tempering.
Chemical composition of Q390A steel:
Q390A steel C: 0.86～0.94
Q390A steel Mn: 0.15～0.40
Q390A steel Si: 0.20～0.45
Q390A steel S: ≤0.030
Q390A steel P: ≤0.030
Q390A steel Cr: 3.80～4.50
Q390A steel V: 1.75～2.10
Q390A steel W: 5.90～6.70
Q390A steel Mo: 4.70～5.20
Mechanical properties of Q390A steel:
Q390A steel yield strength σ0.2 (MPa): ≥680
Q390A steel tensile strength: δbMPa ≥985
Q390A steel elongation δ5%: ≥35
Q390A steel hardness: ≤350HB
Due to the high strength and good wear resistance of Q390A steel, it can also produce wear-resistant parts under high load, such as cold extrusion dies, etc., but at this time the quenching temperature must be appropriately reduced to meet the requirements of strength and toughness. Q390A high-speed steel is easy to oxidize and decarburize, so attention should be paid to it during hot working and heat treatment.
