Ultrahigh-strength steel plate steel plate with yield strength of 960MPa-level, and manufacturing method thereof

Abstract

The invention relates to an ultrahigh-strength steel plate steel plate with yield strength of 960MPa-level, and a manufacturing method thereof. The steel plate comprises the chemical components of: 0.06-0.11% of C, 0.10-0.50% of Si, 1.20-1.60% of Mn, less than 0.015% of P, less than 0.005% of S, 0.20-0.50% of Cr, 0.10-0.30% of Ni, 0.10-0.30% of Mo, 0.02-0.05% of Nb, 0.02-0 .06% of V, 0.008-0.03% of Ti, 0.0005-0.003% of B, 0.02-0.05% of Al, and balance of Fe. According to the invention, through two-stage controlled rolling, and direct quenching and tempering, a refined tempered martensite or lower bainite structure is obtained. Defects such as long process, high energy consumption, large alloy addition amount, and the like of traditional quenching and tempering process are overcome. The obtained steel plate has good toughness and cold bending performance.

Description

technical field [0001] The invention relates to a high-strength steel plate and a manufacturing method thereof, in particular to an ultra-high-strength steel plate with a yield strength of 960MPa and a manufacturing method thereof. Background technique [0002] The ultra-high-strength steel plate with a yield strength of 960MPa has been widely used in structural parts of construction machinery, which has played an important role in improving equipment efficiency, reducing energy consumption and reducing self-weight, and adapts to the continuous development of construction machinery in the direction of high parameterization, large-scale and light weight requirements. At present, the mainstream production process of 960MPa grade steel plate is off-line quenching and tempering treatment, that is, off-line quenching and tempering after hot rolling. More carbon and other alloying elements need to be added, which not only increases the cost of alloying, but also is detrimental to...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide an ultra-high strength steel plate with a yield strength of 960MPa and its manufacturing method, which adopts low-carbon and multi-element and small alloy composition design, and produces 960MPa ultra-high-strength steel plate through controlled rolling and online quenching process , to overcome the technical problems of long traditional quenching and tempering process, high energy consumption, and large amount of alloy addition

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