Highly-reamed hot-rolled pickling steel plate with 440 MPa grade tensile strength

Abstract

The invention relates to a highly-reamed hot-rolled pickling steel plate with 440 MPa grade tensile strength. The technical problem of low reaming and flanging machining performance of an existing highly-reamed hot-rolled pickling steel plate with the 440 MPa grade tensile strength is mainly solved. The highly-reamed hot-rolled pickling steel plate with the 440 MPa grade tensile strength is prepared from the following chemical compositions in percentage by weight: 0.035%-0.055% of C, 0.40%-0.60% of Si, 0.95%-1.05% of Mn, no more than 0.015% of P, no more than 0.005% of S, 0.020%-0.0. 60% of Aland the balance of iron and inevitable impurities. The after-fracture elongation rate A50 mm of the hot-rolled pickling steel plate with the thickness being 1.8-6.0 mm is no less than 30%, and the reaming performance lambda is no less than 120%. The highly-reamed hot-rolled pickling steel plate has good reaming and flanging forming characteristics, and manufacturing of highly-reamed and complexly-formed automobile structural parts with the high flanging amount is met.

Description

Technical field [0001] The invention relates to a hot-rolled pickled steel sheet, in particular to a high-expanded hot-rolled pickled steel sheet with a tensile strength of 440MPa and a manufacturing method thereof. The steel plate of the present invention has good hole reaming and flanging forming characteristics, and meets the requirements of automobile parts The manufacturing requirements of, belong to the field of iron-based alloy technology. Background technique [0002] Hot-rolled steel sheets and hot-rolled pickled steel sheets are widely used in automobile chassis, wheels and body structure parts. With the rapid development of the automobile industry, the automobile industry has higher and higher requirements for lightweight, safety and cost reduction; therefore, in automobile design At the same time, the requirements for chassis structure (control arm, rear axle beam assembly, etc.) are increasing, the shape of its parts is becoming more and more complex, and the strengt...

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Problems solved by technology

[0006] The object of the present invention is to provide a high-reaming hot-rolled pickled steel plate with a tensile strength of 440MPa and its manufacturing method, which mainly solves the hole-enlarging and flanging processing of the existing high-reaming hot-rolled pickled steel plate with a tensile strength of 440MPa Technical issues with poor performance

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