High-strength cold-rolled steel plate with TRIP (transformation induced plasticity) effect and production method thereof

Abstract

The invention discloses a high-strength cold-rolled steel plate with TRIP (transformation induced plasticity) effect, which comprises the following chemical components in percentage by weight: 0.15-0.25% of C, 0.5-1.5% of Si, 1.0-2.0% of Mn, 0.1-0.5% of Ni, at most 0.02% of P, at most 0.005% of S, 0.02-0.08% of Al, and the balance of Fe and inevitable impurities. The method comprises the following steps: continuous annealing: the heating temperature is 800-840 DEG C, the holding time is 150-180 seconds, the cooling rate is greater than or equal to 50 DEG C / second, the quenching temperature is 250-280 DEG C, the partitioning temperature is 350-400 DEG C, and the partitioning time is 300-600 seconds; and air cooling to room temperature. The tensile strength is greater than 1000 MPa, and the elongation percentage is greater than 18%.

Description

technical field [0001] The invention belongs to the field of cold-rolled automobile steel manufacturing, and relates to a high-strength cold-rolled steel plate with a tensile strength greater than 1000 MPa and TRIP effect and a production method thereof. Background technique [0002] The lightweight of automobiles is the main way to reduce fuel consumption, and it is also the most effective countermeasure to reduce carbon dioxide emissions. According to statistics, every 1% reduction in vehicle weight can save 0.6-1.0% of fuel. In addition, as the standards for improving crash safety become stricter year by year, it is necessary to increase the strength and rigidity of the car body and optimize the structure to improve safety. In response to such social needs, we should focus on the use of high-strength materials to improve the safety of cars. Better balance with weight. In order to reduce vehicle weight and improve safety, in recent years, it has become a trend to develop ...

AI Technical Summary

Problems solved by technology

[0009] Using the traditional continuous annealing process for TRIP steel, it is necessary to increase the C content or add a large amount of alloying elements to produce steel plates with a tensile strength above 980 MPa, which has the disadvantages of decreased welding performance and surface coating performance; The production of high-strength and high-plasticity steel plates by the Q&P process requires heating the steel plates above the Ac3 temperature, and requires a high cooling rate, high requirements for production equipment, and high energy consumption.

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