High-strength cold-rolled plate with favorable forming property and preparation method thereof

Abstract

The invention provides a high-strength cold-rolled plate with favorable forming property and a preparation method thereof. The high-strength cold-rolled plate comprises the following chemical components: 0.05-0.6% of C, being more than or equal to 0.3% and being less than 0.8% of Si, 0.5-4.0% of Mn, being more than ore equal to 0.2% of P, being more than or equal to 0.002% of S, being more than or equal to 0.1% of Al, being more than or equal to 0.01% of N, and the balance of Fe and inevitable impurities. The preparation method comprises the following steps: smelting, continuous-casting, hot-rolling, cold-rolling and continuous-annealing, wherein annealing temperature is higher than that of Ac3, holding time is 3-30 minutes; quickly cooling to 100-600 DEG C at the rate of 30-100 DEG C / s, keeping the temperature for 3-30 minutes, and finally cooling to room temperature at the rate of 5-30 DEG C / s. The invention adopts low-silicon low-aluminum component design and heat treatment technique; the strength level of the produced bainite TRIP steel is greater than 780 MPa; and the produced bainite TRIP steel has favorable strength, plasticity, extensibility, chambering property and coating property.

Description

technical field [0001] The invention belongs to the technical field of alloy steel, and in particular relates to a high-strength cold-rolled steel plate with good formability and a preparation method thereof. Background technique [0002] With the rise of oil prices and the aggravation of environmental degradation, people have put forward higher requirements for energy saving, environmental protection and safety of automobiles, and the lightweight of automobiles has become a long-term goal of the automobile industry. The application of high-strength steel in automobiles also increasingly popular. In the manufacturing process of auto parts, not only the steel plate is required to have high strength to achieve the purpose of reducing the weight of the vehicle body, but also the steel plate is required to have good formability to ensure that the steel plate can be processed into qualified parts. [0003] Traditional high-strength low-alloy steel is the main steel used to manuf...

AI Technical Summary

Problems solved by technology

However, this process adopts the method of quenching and tempering, the production process is complicated, and it is difficult to realize it on the existing continuous annealing production equipment

[0006] The application number is 200710091779.2, and the Chinese patent titled "High-strength steel plate with excellent stretch flangeability" proposes a high-strength steel plate based on bainite and retained austenite, which has high strength, high elongation and Hole expansion performance, its disadvantage is to adopt high Si composition design, in which the Si content is between 0.8-2.5%, and the higher silicon content will cause the decline of the surface quality of the steel plate, so that the hot rolling performance and surface coating performance of the steel plate will be greatly reduced

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