High-tenacity spring steel and heat treatment technology thereof

The invention belongs to the technical field of spring steel metallurgy, in particular to high-tenacity spring steel and a heat treatment technology thereof. The high-tenacity spring steel comprises components in percentage by mass of: 0.34-0.49% of C, 1.00-2.80% of Si, 0.60-1.50% of Mn, 0.50-2.0% of Cr, 0.006-0.008% of P, 0.002-0.005% of S, 0.1-0.5% of Ni, 0.05-0.5% of Mo, 0.05-0.20% of V, 0.015-0.035% of Al, 0.0035-.0065% of N, 0.0005-0.01% of Ni, 0.23-0.25% of rare earth microelements and the balance Fe and inevitable impurities. The heat treatment technology mainly adopts reversible type rolling and low temperature tempering treatment, fully continuous rolling and warm tempering treatment, and water-cooling finishing rolling. The high-tenacity spring steel prepared by the heat treatment technology disclosed by the invention is manly suitable for producing and processing of high-tenacity spring steel products, such as manufacturing of spring spare parts high in design stress and long in fatigue life. The h