High-strength steel with yield strength of 700MPa and TMCP manufacturing method

Abstract

The invention discloses high-strength steel with the yield strength of 700MPa and a TMCP manufacturing method, and belongs to the technical field of production of the high-strength steel. The high-strength steel comprises chemical compositions including, by mass, 0.07% to 0.10% of C, 0.15% to 0.40% of Si, 1.20% to 1.80% of Mn, 0% to 0.40% of Cr, 0% to 0.30% of Mo, 0% to 0.30% of Ni, 0% to 0.0020% of B, 0% to 0.070% of Nb, 0% to 0.070% of V, 0% to 0.020% of Ti, 0% to 0.050% of Alt, not larger than 0.015% of P, not larger than 0.010% of S, 0.40% to 0.50% of carbon equivalent Ceq, and the balanced Fe and inevitable impurities. The method comprises the steps of slab casting after smelting, slab heating, billet heating, rolling and water cooling. The high-strength steel has the advantages that a performance index is stable, the requirement of the ultrahigh-strength steel for the performance can be completely met, and the good strength, plasticity, toughness and welding performance can be achieved.

Description

technical field [0001] The invention belongs to the technical field of high-strength steel production, and in particular relates to a high-strength steel with a yield strength of 700 MPa and a TMCP manufacturing method. Background technique [0002] With the rapid development of my country's machinery manufacturing industry, the requirements for the strength, toughness, plasticity and weldability of steel for construction machinery are getting higher and higher; in order to improve production efficiency, reduce the weight of equipment and reduce energy consumption in the construction machinery manufacturing industry, for The demand for steel for construction machinery with higher strength is increasing. [0003] At present, a variety of process methods can be used to produce high-strength engineering machinery steel. At present, the more common ones are controlled rolling and controlled cooling + tempering process (TMCP + tempering process), controlled rolling + quenching and...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a high-strength steel with a yield strength of 700MPa and a TMCP manufacturing method, which solves the problem of reducing the production cost of steel plates for construction machinery with a yield strength of 700MPa, and at the same time needs to have better strength, plasticity, toughness and excellent welding performance.

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