Ultra-high-toughness nickel containing nanoscale bainite steel and preparation method thereof

Abstract

The invention relates to an ultra-high-toughness nickel containing nanoscale bainite steel and a preparation method thereof. The technical scheme adopted by the invention is that the preparation method comprises the following steps: heating a steel billet to 1250-1300 DEG C, preserving heat for 1-2 hours, rolling at the temperature higher than Ar3 temperature, wherein the final rolling temperatureis 880-920 DEG C, and performing air cooling to room temperature; heating to 880-920 DEG C at the rate of 5-8 DEG C / min, and preserving heat for 30-60 min; and then performing water cooling to 200-230 deg c, preserving heat for 30-35 hours, and performing air cooling to room temperature, thereby preparing the ultra-high-toughness nickel containing nanoscale bainite steel. The steel billet comprises the following chemical components: 0.78-0.83 wt% of C, 1.55-1.65 wt% of Si, 1.96-2.06 wt% of Mn, 0.295-0.305 wt% of Mo, 0.98-1.02 wt% of Cr, 0.98-1.02 wt% of Ni, 0.98-1.02 wt% of Al, 1.482-1.502 wt% of Co, less than 0.008 wt% of P, less than 0.002 wt% of S, less than 0.004 wt% of N, and the balance of Fe and inevitable impurities. The process is simple, large-scale industrial production is realized, and the product prepared according to the preparation method is excellent in mechanical property.

Description

technical field [0001] The invention belongs to the technical field of ultra-high strength and toughness bainitic steel. In particular, it relates to an ultra-high strength and toughness nickel-containing nano-scale bainite steel and a preparation method thereof. Background technique [0002] Ultra-high-strength bainitic steel is mainly used in construction machinery, marine facilities, bridges, rails, automobiles, shipbuilding, and armor plates. With the development of science and technology and various technologies, the requirements for its strength and toughness are increasing. For example, the development of the automobile industry requires cheap, high-strength and high-formability steel to manufacture lighter and complex-shaped automotive structural parts with thinner steel plates; the development of high-speed trains requires high-strength and wear-resistant steel rails to meet the high-speed operation of trains long enough life. Therefore, ultra-high strength and to...

AI Technical Summary

Problems solved by technology

Although there are relatively few types of alloying elements in steel, except for Mo, cheap C, Si, Mn, Al, etc. are often used instead of expensive alloying elements, but the tensile properties of steel are ordinary, which does not meet the increasing strength and toughness of steel materials. Industrial production requirements; in addition, the two-step rolling process of austenitic hot rolling and quenching isothermal deformation for 0.5-2.5h is used in the heat treatment process. The production process is complicated and difficult to achieve in industrial production, which is not conducive to mass production

[0007] From the above analysis, it can be seen that the existing high-strength bainitic steel production process is generally complicated and not suitable for industrialized large-scale production, and the mechanical properties of the final prepared bainitic steel cannot meet the industrialization requirements of continuous improvement in the strength and toughness of steel materials. Production requirements