High intensity and high-toughness hot-rolled steel sheet and method for producing the same

Abstract

The invention discloses a high strength and high toughness hot-rolled steel plate, the chemical components thereof and the weight percentages of the component are: 0.03 to 0.09 percent of C, 0.15 to 0.35 percent of Si, 1.40 to 2.0 percent of Mn, 0.02 to 0.05 percent of Al, 0.05 to 0.13 percent of Nb, 0.010 to 0.025 percent of Ti, being equal to or less than 0.30 percent of Cu, being equal to or less than 0.30 percent of Cr, being equal to or less than 0.012 percent of P, being equal to or less than 0.004 percent of S, being equal to or less than 0.004 percent of N and the rest are Fe; and Ceq can not be more than 0.44, crack sensitive index Pcm can not be more than 0.23, the production steps thereof are: liquid iron pre-desulphurization, bessemerizing, LF refining, RH(VD) processing, slab blank continuous casting, slab blank reheating, temperature controlling rolling, controlled cooling, hot straightening, cold bed cooling and cooling in heap; the advantages thereof are as follows: molybdenum can be omitted and nickel can be saved, thus reducing the cost; the steel plate has good weldability, high rolling efficiency and precise production control.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and relates to the technical field of micro-alloyed high-strength low-alloy controlled-rolling and controlled-cooling steel, in particular to a hot-rolled steel plate with high strength, high toughness and weldability, such as large-diameter X70 or more Production methods of pipeline steel, steel plate for pressure vessel, steel plate for marine structure, high-strength bridge plate and steel for construction machinery. Background technique [0002] In recent years, in the field of steel plate application, with the increasing size of structural parts, the increasing energy efficiency of pressure vessels, the development trend of large diameter and high gas transmission pressure of oil and gas pipelines, and the development trend of low temperature application environment, it is required to increase the strength of steel plates and reduce the While increasing the weight of the steel structure, t...

AI Technical Summary

Problems solved by technology

However, in the prior art, most of the trace metal elements such as molybdenum, vanadium and nickel contained in the hot-rolled steel plate with high strength, high toughness and good weldability are relatively expensive, so the cost of the product is relatively high

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