High-plasticity cold roll forming steel with tensile strength of 500 MPa and production method

Abstract

The invention relates to high-plasticity cold roll forming steel with tensile strength of 500 MPa. The steel comprises the following chemical components, in percentage by weight, of 0.085% to 0.18% of C, less than or equal to 0.10% of Si, 0.50% to 0.90% of Mn, less than or equal to 0.025% of P, less than or equal to 0.020% of S, 0.010% to 0.040% of Al, and 0.020% to 0.060% of Ti. The production method comprises the following steps of conducting, after smelting in a converter, argon blowing treatment in a tundish; continuously casting to form a blank; heating the casting blank; conducting rough rolling; conducting finish rolling; and coiling. According to the steel, on the premise that the tensile strength is 500 MPa to 570 MPa, the yield strength is 370 MPa to 420 MPa, the elongation is larger than or equal to 30%, KV2 at a temperature of -20 DEG C is larger than or equal to 82 J, a bending center diameter d in a cold bending test is a thickness a of a sample, and cracks cannot be generated when a cold bending angle is 180 degrees.

Description

technical field [0001] The invention relates to steel for cold-bending forming and a production method thereof, in particular to steel for cold-bending forming with a tensile strength of 500 MPa and high plasticity and a production method thereof. Background technique [0002] Downstream enterprises in the steel industry often need to further process steel and make it into engineering structural parts before they can be put into use. Cold roll forming is one of the most common processing methods. Cold-formed steel is a steel strip that is continuously bent transversely by sequentially configured multi-pass forming rolls at room temperature to manufacture steel products with specific cross-sections. Cold-formed steel has the advantages of high dimensional accuracy, high strength, light weight, high metal utilization, reasonable cross-sectional shape, and flexible supply. It is an energy-saving and efficient economical cross-section steel, which is widely used in many fields o...

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Problems solved by technology

The disadvantage is that the addition of precious element Nb increases the production cost; the heating temperature of the billet, the rough rolling exit temperature, the final rolling temperature and the coiling temperature are strictly limited, the production process window is narrow, and the production difficulty is increased; the impact performance of the steel is not affected. introduce

The public publication (Birzer, F.SheetPurchase Specifications and Tests With Respect to Manufacturing Process.SheetMetal Working'84.1984(7-8Nov):51-80) has carried out cold bending test research on steel with different components, and proposes that the carbide Only when the size is controlled within a certain range can good ductility be obtained. A group of steel used in the test contains 0.061% Al and 0.18% Ti. This solution will lead to difficult production control and low component hit rate

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