High-elongation hot-rolled structure regulated and controlled steel with tensile strength greater than or equal to 1200 MPa and production method

Abstract

The invention discloses high-elongation hot-rolled structure regulated and controlled steel with the tensile strength greater than or equal to 1200 MPa. The steel comprises the following components of, by weight, 0.19%-0.21% of C, 1.60%-1.80% of Mn, 0.60%-0.70% of Si, less than or equal to 0.008% of P, less than or equal to 0.002% of S and 0.02%-0.04% of Als. The production method comprises the following steps that smelting is performed by a converter, and then RH vacuum furnace treatment is performed; a casting blank is heated; staged rolling is performed; staged variable-speed cooling is performed; coiling is performed; heat preservation is performed; and leveling treatment is performed. According to the steel and the production method, under the condition that Nb, V, Mo and other alloysare not added, it can be guaranteed that the tensile strength is 1200 MPa or above, the elongation is greater than or equal to 15%, the thickness of a steel plate is 7-12 mm, then the forming requirement of thick-specification high-strength steel can be met, and the alloy cost is reduced by at least 10%.

Description

technical field [0001] The invention relates to a hot-rolled steel for automobiles and a production method thereof, in particular to a high-elongation hot-rolled structure control steel with a tensile strength greater than 1200MPa and a production method; and is suitable for steel plates with a thickness of 7-12mm. Background technique [0002] In recent years, the automotive industry, especially commercial vehicles, semi-trailers, passenger cars and other market segments, has become more and more urgent to reduce weight. Related manufacturers have put forward clear requirements for vehicle weight reduction to meet the mandatory national standard GB1589-2016, etc. regulatory requirements. On the one hand, the wheels, axles, saddles and other structural parts of commercial vehicles and other models need to be drawn, reamed and other forming processes in the manufacturing process. There are clear requirements for edge forming performance. On the other hand, the thickness of s...

AI Technical Summary

Problems solved by technology

The thickness of this invention is only 1.0-3.0mm, which cannot meet the requirements of 7-12mm thick steel for commercial vehicle axles, saddles and other parts

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