Steel with tensile strength not lower than 1100MPa for engineering machinery and production method thereof

Abstract

The invention relates to steel with tensile strength larger than 1100MPa for engineering machinery and a production method thereof. The steel comprises the following chemical components in percentage by weight: 0.09-0.12% of C, 0.50-0.75% of Si, 1.20-1.60% of Mn, not more than 0.025% of P, not more than 0.025% of S, 0.01-0.03% of Nb, 0.030-0.060% of Ti, 0.0010-0.0050% of B, and the balance of Fe and inevitable impurities, wherein Nb+Ti is not more than 0.08% and Ti / B is 6-35. The production method comprises the following steps of: pouring into a blank through molten iron desulfurization, converter top and bottom blowing, RH vacuum treatment and component micro-adjustment, and full-flow protection; heating the cast blank; and carrying our rough rolling, finish rolling and heat treatment. The steel has the advantages that: the components are simple, the process is simple, and the yield and performance qualification rate are high; after heat treatment, the steel board has Rm not lower than 1100MPa and (-20) DEG C KV2 not lower than 30 J, thereby completely meeting the use requirements; and the steel board has good cold bending shaping property, wherein b=2a, d=3a, and the steel boardis qualified after bending 180 degrees.

Description

technical field [0001] The invention relates to the technical field of alloy steel production, belongs to steel for engineering machinery, in particular to an economical steel for engineering machinery with a tensile strength greater than 1100 MPa and a production method thereof. Background technique [0002] Higher strength and longer service life of steel are one of the trends in the development of steel. The reduction in steel usage brought about by it is not only one of the important ways to save energy and reduce emissions, but also can significantly improve the use efficiency and efficiency of equipment in the steel application industry. The level of safety is of great significance to the development of the steel industry and the national economy. [0003] Since high-strength steel is generally used in coal mining machinery, construction machinery and other industries, its performance requirements are high. In addition to high strength, it must also have good plasticit...

AI Technical Summary

Problems solved by technology

Application No. CN200910051932 discloses a quenched and tempered steel plate for construction machinery with a yield strength of 900Mpa and a production method thereof, but compared with this patent, its chemical composition contains precious metals such as Cr, Ni, Mo, etc., and its economy is poor. The heat treatment process adopts Quenching + high temperature tempering to obtain a tempered sorbite structure, the tensile strength is 1000-1050Mpa, which is far from the present invention

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