12.0-16.0 mm thick high-toughness 700MPa grade automobile beam steel and production method thereof

Abstract

The invention discloses 12.0-16.0 mm thick high-toughness 700MPa grade automobile beam steel and a production method thereof. The beam steel comprises the following chemical components of, in percentage by weight, 0.06 %-0.0 9 % of C, 0.10 %-0.30 % of Si, 1.60 %-1.90 % of Mn, smaller than or equal to 0.020 % of P, smaller than or equal to 0.005 % of S, 0.020 %-0.050 % of Alt, 0.04 %-0.06 % of Nb,0.06 %-0.10 % of Ti, smaller than or equal to 0.0050 % of N, and the balance Fe and inevitable impurities. The invention also discloses the production method of the beam steel. According to the beam steel and the method, the metallographic structure of the automobile beam steel is ferrite and pearlite, wherein the content of the pearlite is smaller than 10 %, and the grain size is larger than or equal to 12 level; and a rolling technology is optimized to produce the automobile beam steel which is thick and good in strength and toughness matching, so that the specification range of the automobile beam steel with the strength level is widened.

Description

technical field [0001] The invention relates to the technical field of production of thick-gauge high-strength steel, especially has high strength, excellent plasticity, low-temperature impact toughness and welding performance, and is mainly used for automobile structures such as automobile beams and longitudinal beams that require good forming and processing performance and high strength requirements Parts, especially relate to a 12.0-16.0mm thick high toughness 700MPa grade automobile frame steel and its production method. Background technique [0002] With the development of the economy, automobiles have played an increasingly important role in industrial and agricultural production and people's daily life. At the same time, the widespread application of automobiles has brought many problems while facilitating people's production and life. Consumption, environmental pollution and other issues. Therefore, the lightweight of automobiles has become an important topic for th...

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Problems solved by technology

Patent CN109161806A discloses a 700MPa grade automobile beam steel strip and its preparation method, only publishes the mechanical properties with a thickness of 14.0mm, and the thickness specification is single

[0008] In short, the 700MPa grade automobile frame steel involved in the above documents and patents has technical problems such as thickness specifications not exceeding 14.0mm and low strength.

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