Air-cooled hardened steel plate with ultra-high strength, high toughness and ultra-fine structure and preparation process of air-cooled hardened steel plate

Abstract

The invention relates to an air-cooled hardened steel plate with ultra-high strength, high toughness and an ultra-fine structure and a preparation process of the air-cooled hardened steel plate. The air-cooled hardened steel plate comprises the following components in percentage by mass: less than or equal to 0.08% of C, 0.1-0.35% of Si, 0.2-0.8% of Mn, 10-15% of Cr, 2.0-3.0% of W, 2.0-3.0% of Co,0.1-0.3% of V, 0.025-0.08% of Nb, 0.03-0.06% of N, 0.05-0.1% of Ta, 0.02-0.06% of Nd, less than or equal to 0.0005% of B and the balance of Fe and inevitable impurities. The preparation process comprises the steps of smelting, hot working treatment, secondary intermediate annealing treatment, medium-temperature strong deformation heat treatment and low-temperature aging treatment. Structural regulation and control are conducted through conventional equipment and production process, the martensite structure can be refined to the nanoscale, furthermore, a large number of nano-particles are separated out and distributed in a matrix in a dispersed mode, and the comprehensive performance of the low-carbon martensite steel plate is remarkably improved. Compared with the prior art, the preparedmaterial has ultrahigh strength, high toughness, good corrosion resistance, oxidation resistance, heat resistance and low-temperature performance. The preparation process is simple, industrial large-scale production is facilitated, production cost is low, production efficiency is high, and the product application range is wide.

Description

technical field [0001] The invention relates to the field of ultra-high-strength steel and its processing technology, in particular to an air-cooled hardened steel plate with ultra-high strength, high toughness and ultra-fine structure and a preparation process thereof. Background technique [0002] The iron and steel industry is an important industry that promotes the development of the country. Because of its extremely high strength and good plasticity and toughness, ultra-high-strength steel has a wide range of applications in heavy machinery, advanced mold manufacturing, high-speed railways, aerospace, major national defense equipment, and automobiles. application. In recent years, with the rapid development of industry and the increasing pressure on resources and environment, the country's demand for ultra-high-strength steel is also increasing. As a traditional ultra-high-strength steel, air-cooled hardened steel generally has a C content between 0.3% and 0.5%, and al...

AI Technical Summary

Problems solved by technology

Invention patent CN108728621B discloses a method of high temperature treatment and applying compressive stress to refine martensitic steel strips. This inventive method has strict requirements on sample size and equipment, which is not conducive to large-scale industrial production

The patented method of the present invention significantly refines the original austenite grains through the combination of high-temperature forging and medium-temperature forging, so that the tensile strength of martensitic steel is increased to 1950-2160 MPa, and the elongation is maintained in the range of 9-14%. High-temperature forging is a high-energy-consuming process with high production costs and is not conducive to environmental protection

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