Low-carbon silicon-manganese bainite high-strength steel and production method thereof

Abstract

The invention discloses low-carbon silicon-manganese bainite high-strength steel and a production method thereof. The method comprises a hot rolling process, a cold rolling process and a heat treatment process. The method adopts slabs for hot rolling, and the slab comprises the following chemical components in percentage by mass: 0.15-0.22 percent of C, 1.2-1.8 percent of Si, 1.5-1.8 percent of Mn, at most 0.05 percent of P, at most 0.03 percent of S and the balance of Fe and inevitable impurities. The heat treatment process comprises the following steps: raising the temperature of finished rolling plates obtained in the cold rolling process to 780-820 DEG C at the speed of 8-12 DEG C / s, and preserving heat for 1000-1800s; finally carrying out Q and PB processing, and thus obtaining the high-strength steel. The method adopts a design of component optimizing, so that the cost of raw materials is reduced. Through two-phase zone Mn partition in advance, Mn elements in austenite are non-uniformly distributed, the stability of the austenite before quenching is improved, and therefore and therefore the content of the retained austenite at room temperature is increased. Further, the TRIP effect is increased, and the toughness and the elongation are improved. The method has the advantages of being simple in process, convenient to industrialized production and short in isothermal time and effectively improves the production efficiency.

Description

technical field [0001] The invention relates to a high-strength steel and a production method thereof, in particular to a low-carbon silicon-manganese bainitic high-strength steel and a production method thereof. Background technique [0002] With the development of science and technology and the progress of society, the demand for various materials in the manufacturing industry is also getting higher and higher, and the performance requirements of materials are becoming more and more stringent. There is no doubt that the development of steel materials is very important. It promotes the entire Developments in the materials world. As a new type of material, bainitic steel has excellent mechanical properties. Since Danemport and E.C.Bain first discovered bainite in steel in the 1930s, many domestic and foreign researchers have done a lot of research work on it in the following decades. The theory of bainite has also made great progress, so the development and use of bainite ...

AI Technical Summary

Problems solved by technology

They all have excellent wear resistance, high strength and toughness, and have been initially applied in the fields of mining, electric power, metallurgy, building materials, etc., but their production processes are relatively complicated, the production efficiency is low, there are many alloy elements, and the production cost is high.

In recent years, there has been research on nano-bainite. Although the process is simple and the addition of alloy elements is less, its isothermal time is longer and its strength is high, but its toughness is not good and its application field is narrow.

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