Martensite non-tempered high-strength steel with tensile strength larger than or equal to 960 MP and manufacturing method thereof

Abstract

The invention belongs to the technical field of steel making, and particularly relates to a martensite non-tempered high-strength steel with tensile strength larger than or equal to 960 MP and a manufacturing method thereof. The technological process of the manufacturing method comprises the steps of pretreatment of liquid iron, converter smelting, LF refining, RH refining, continuous casting, heating, 2300mm hot continuous rolling, controlled cooling, winding, annealing, sampling and function testing. According to the martensite non-tempered high-strength steel with the tensile strength larger than or equal to 960 MP, a non-tempered 960 MPa high-strength hot rolled steel plate has the excellent mechanical property and good machining properties such as cutting and welding, the blank of this type of a domestic steel grade is filled, imported products similar to the steel can be replaced, steel types of enterprises are increased, the high final product quality and the high rate of finished products are achieved, the martensite non-tempered high-strength steel with the tensile strength larger than or equal to 960 MP has great economic benefit.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, and specifically relates to a martensitic non-quenched and tempered high-strength steel with a tensile strength ≥ 960MP and a manufacturing method thereof. Background technique [0002] At present, foreign developed countries pay great attention to the use of high-strength structural steel in terms of steel for steel structure. The minimum strength level of the steel is 275MPa, and 420, 460, 490, 550, 590MPa steel has been used in large quantities, and corresponding specifications are provided. Standards, the world's major industrial countries have developed their own steel series for construction machinery. For example, SSAB in Sweden and JFE in Japan have developed high-strength steel plates with a strength grade of 1100MPa through reasonable microalloying composition design and advanced production technology. The steel plates of 960MPa and above required by my country's construction machi...

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Problems solved by technology

[0003] In recent years, my country has also carried out research work on ultra-high-strength steel. The Iron and Steel Research Institute has developed a new microstructure control technology through in-depth research on microalloying technology and the development of new heat treatment technology. It is currently developing Q960MPa, Q1100MPa, In the research and development of Q1300MPa steel for construction machinery, Baosteel also developed a 960MPa ultra-high-strength steel production line, but failed to achieve stable mass production

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