600 MPa-level high-strength low-alloy cold-strip steel and production method thereof

Abstract

The invention discloses 600 MPa-level high-strength low-alloy cold-strip steel and a production method thereof. The cold-strip steel comprises the chemical components: 0.08%-0.11% of C, 0.4%-0.5% of Si, 1.65%-1.75% of Mn, 0.015% or less of P, 0.012% or less of S, 0.02%-0.045% of Als, 0.005% or less of N, 0.02%-0.03% of Ti, 0.03%-0.04% of Nb and the balance Fe, the hot rolling heating temperature ranges from 1,230 DEG C to 1,270 DEG C, the final rolling temperature ranges from 876 DEG C to 904 DEG C, the coiling temperature ranges from 633 DEG C to 667 DEG C, the continuous annealing soaking temperature ranges from 740 DEG C to 760 DEG C, the slow-cooling temperature ranges from 660 DEG C to 680 DEG C, the rapid cooling temperature ranges from 450 DEG C to 470 DEG C, and the elongation of temper rolling ranges from 1.2% to 1.4%. According to the 600 MPa-level high-strength low-alloy cold-strip steel, by utilizing Nb and Ti element precipitation strengthening and Si element solution strengthening, component precise control is achieved, the technical parameters are improved, the cost is reduced, and the product obdurability is improved.

Description

technical field [0001] The invention relates to a 600MPa grade high-strength low-alloy cold-rolled steel strip and a production method thereof, belonging to the technical field of metallurgical plate production. Background technique [0002] With the continuous development of the times, automobiles have become an indispensable means of transportation in modern life. With the improvement of people's awareness of energy saving and environmental protection, cars with low energy consumption and high safety are increasingly favored by people. Steel plates, which are the main raw materials for automobiles, need to continuously increase their strength while reducing their weight. At present, 600MPa high-strength low-alloy steel is widely used in automotive structural parts and reinforcements, which can better achieve the purpose of lightweight and energy-saving automobiles. [0003] The Chinese patent with the publication number 103088261A and the publication date of 2013-05-08 d...

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Problems solved by technology

[0003] The Chinese patent with the publication number 103088261A and the publication date of 2013-05-08 discloses "a high-strength cold-rolled steel plate with a tensile strength of 600 MPa and its production method", the publication number is 105274432A, and the publication date is 2016-01-27 The patent discloses "a 600MPa-grade high-yield-ratio high-plasticity cold-rolled steel plate"; both of the above two patents use Nb and Ti composite strengthening, and the Si content is relatively small, but the composition is relatively broad, which is not conducive to stable production, and Ti and Nb noble metal alloy content is higher, and the production cost of the steel plate is relatively high; the Chinese patent with the publication number 102492823 A and the publication date of 2012-6-13 discloses "continuous annealing process for cold-rolled low-alloy high-strength steel plate with yield strength of 420MPa", the The ingredients in the patented technical solution are too broad to carry out industrial production according to this ingredient, and the tensile strength is only 500Mpa

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