Rare earth treated thick 700 MPa-grade automobile beam steel strip and manufacturing method thereof

Abstract

The invention discloses a rare earth treated thick 700 MPa-grade automobile beam steel strip. The rare earth treated thick 700 MPa-grade automobile beam steel strip comprises the following chemical components in percentage by weight: 0.06-0.09% of C, 0.10-0.30% of Si, 1.60-1.90% of Mn, no more than 0.020% of P, no more than 0.005% of S, 0.020-0.050% of Alt, 0.04-0.06% of Nb, 0.07-0.10% of Ti, no more than 0.0040% of N, 0.00100-0.0030% of Ce, and the balance of Fe and inevitable impurities. The invention further discloses a manufacturing method of the rare earth treated thick 700 MPa-grade automobile beam steel strip. The alloy component design adopts Nb-Ti microalloy, contains no noble element Mo, and aims to fully exert such characteristics as modification of rare earth inclusions, grainrefining and improvement of low-temperature impact toughness through adding rare earth elements; and through matching with optimized heating and rolling processes, automobile beam steel with thick specification and excellent toughness matching is produced, and the specification range and the use temperature range of the strength-grade automobile beam steel are widened.

Description

technical field [0001] The invention relates to the technical field of metallurgy, in particular to a rare earth-treated 700MPa-grade automobile frame steel belt and a manufacturing method thereof. Background technique [0002] Reducing the weight of the vehicle body by increasing the strength of the steel plate, reducing consumption, saving energy, and reducing environmental pollution are important topics in the research of today's automobile industry. At home and abroad, at this stage, some microalloying elements are mostly used to strengthen the strength of steel. Girder steel, as a safe load-bearing part of passenger and freight vehicles, has high requirements on performance and formability. However, the alloying elements, dosage, and process used are different, and are related to the equipment, technology, and raw materials of each factory. At present, the production technology of girder steel below 700MPa is quite mature, and it is widely used in the automobile indus...

AI Technical Summary

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 the thickness specification not exceeding 15.0mm and high manufacturing costs.

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