Anti-oxidation ultrahigh-strength steel plate for hot stamping forming and low-temperature thermoforming process thereof

Abstract

The invention provides an anti-oxidation ultrahigh-strength steel plate for hot stamping forming and a low-temperature thermoforming process thereof, and belongs to the technical field of steel materials. The steel plate is prepared from, by weight, 0.20%-0.35% of C, 6%-8% of Mn, 2%-5% of Cr, 0.05%-0.3% of Nb and V, 0.3%-0.8% of Si, 0.1%-0.8% of Al and the balance Fe. The hot forming heating temperature of the steel plate can range from 720 DEG C to 770 DEG C, and the oxidation weight increase of the steel plate in the thermoforming process is less than 0.5 g / m<2>; the thickness of an oxidation layer is less than or equal to 2.5 micrometers, the yield strength after thermoforming is greater than or equal to 1,400 MPa, the tensile strength is greater than or equal to 1,700 MPa, and the total elongation is greater than or equal to 11%; the oxidation weight increase of the steel plate in the thermoforming process with a higher temperature ranging from 780 DEG C to 900 DEG C is less than or equal to 6.5 g / m<s>, the thickness of the oxidation layer is less than or equal to 18.7 micrometers, the tensile strength of the formed steel plate is greater than or equal to 1,880 MPa, and the total elongation is greater than or equal to 14%; and the steel plate can be used for automobile safety components and other high-strength components. According to the anti-oxidation ultrahigh-strength steel plate for hot stamping forming and the low-temperature thermoforming process thereof, energy conservation, consumption reduction, low-temperature warm forming and oxidation prevention are achieved, a currently applied anti-alumina silicon coating cannot be coated, the cost is reduced, and the mechanical property of the thermoformed steel plate is obviously improved.

Description

technical field [0001] The invention relates to the technical field of iron and steel materials, in particular to an oxidation-resistant ultra-high-strength steel plate for hot stamping and a low-temperature hot forming process thereof. Background technique [0002] Automobiles have brought great convenience to modern life, completely changed the way people travel, and promoted the development of society. At the same time, they have also brought about serious resource consumption and environmental problems such as automobile exhaust. The lightweight of automobiles can improve fuel efficiency, reduce fuel consumption, reduce exhaust pollution, and alleviate the negative impact of the automobile industry. The lightweight of automobiles requires that the weight of the automobile itself be reduced while ensuring the safety of the body, so the use of high-strength steel has become an inevitable trend. However, the increase in the strength of steel materials usually reduces its f...

AI Technical Summary

Problems solved by technology

This method lowers the temperature required for hot stamping to 730-780°C and cools the stamping to 30-150°C below the Ms point (that is, usually to 150-280°C), and then puts the parts into a heating chamber with a temperature of 150-450°C. In the furnace, keep warm for 1-5 minutes and then cool in air or furnace to further improve the plasticity of the parts, but the yield strength of the material when the elongation exceeds 10% is difficult to reach 1200MPa

In this method, the component is cooled to a specific temperature of 150-280°C, and then the temperature is raised to 150-450°C for heat preservation. It is difficult to control the temperature accuracy and uniformity of the component, which is not conducive to the actual production of hot stamping formed components.

Images