A kind of Cu alloyed deep drawing dual-phase steel plate and preparation method thereof

Abstract

The invention discloses a Cu alloying deep drawing dual-phase steel plate and a preparing method thereof, and belongs to the technical field of metal material machining. The steel plate comprises chemical components including, by weight percent, 0.015 to 0.030% of C, 0.10 to 0.30% of Si, 0.10 to 0.30% of Mn, 0.40 to 0.60% of Cu, 0.30 to 0.50% of Ni, not larger than 0.020% of P, not larger than 0.0030% of S, not larger than 0.0040% of N, 0.010 to 0.025% of Ti, and the balance Fe and inevitable residual impurities. According to design components, conventional smelting and casting are carried out, through acid pickling and cold rolling, the steel plate is rolled to the target thickness, annealing is carried out on a continuous annealing production line, through control over recrystallizationand phase changes in the annealing process, ferrite grains sufficiently recrystallize and grow, solid solution carbon is reduced, the high r value is obtained, the product tensile strength is larger than or equal to 390 MPa, the ductility is larger than or equal to 25%, the r is larger than or equal to 1.40, the production process is simple, operation is feasible, and the needs of car covering parts and complex structural parts with the higher forming property are met.

Description

Technical field: [0001] The invention belongs to the technical field of metal material processing, and relates to a cold-rolled deep-drawing dual-phase steel for automobiles, in particular to a cold-rolled ferrite-martensite dual-phase steel with high strength and high plastic strain ratio obtained by Cu alloying Steel plate and its preparation method. Background technique: [0002] With the development of the automobile industry and the increasingly acute energy and environmental issues, in order to meet the challenges of energy shortage and environmental pollution, reduce energy consumption and exhaust emissions, the automobile industry has carried out various technologies to improve fuel economy, among which lightweight It is the most significant technology to improve fuel economy. Experiments have proved that if the weight of the vehicle is reduced by 10%, the fuel efficiency can be increased by 6% to 8%. At present, the lightweight materials of automobiles include alu...

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Problems solved by technology

[0003] At present, relevant documents related to deep-drawing dual-phase steel are disclosed as follows: Chinese patent CN104233093A discloses a low-carbon and low-silicon cold-rolled hot-dip galvanized dual-phase steel for high-ultra-deep drawing and its preparation method. Precious metal Cr and Mo elements, and use texture pretreatment process for production, before the final annealing, texture pretreatment annealing process is required, the process flow is long, and the strip is prone to bonding during the pretreatment annealing process, which affects the shape and shape of the strip. Surface quality, while not conducive to economical production

Chinese patent CN102286696A discloses a method for preparing ultra-deep drawing dual-phase steel with high plastic strain ratio. This invention adds a certain amount of precious metals Al, Cr and Mo to the steel. The Al content is relatively high. During the continuous casting process In the process of manufacturing, using the principle of low-temperature precipitation of Mo carbide and high-temperature re-dissolution, Mo is prone to re-dissolution under annealing temperature conditions, and the interstitial C atoms in the steel are difficult to accurately control, thus affecting {111 } / / Formation and development of ND texture

Because the sub-temperature annealing temperature is too high, there will be bonding between the steel strips during the annealing process, which will affect the shape and surface quality. At the same time, the two-step heat treatment process will increase the process flow, which is not conducive to economical production.

Chinese patent CN103243260A discloses deep drawing dual-phase steel and its production method. This invention controls the solid solution carbon content in the steel through Nb by adding higher Nb elements to the steel, using the principle of NbC precipitation at low temperature and high temperature remelting. The method has high requirements on the control of continuous annealing temperature. A slightly higher temperature will increase the solid solution C content of the steel, thereby affecting the formation of the {111} / / ND texture of the steel; Easy to produce cold and brittle phenomenon during secondary processing

Chinese patent CN103469089A discloses a pie-shaped grain deep-drawing dual-phase steel plate and its preparation method. The invention uses the principle of cake-shaped grains and structure inheritance of low-carbon aluminum-killed steel during the annealing process. In the subsequent annealing process Leaving the cake-shaped grains, this method also requires tissue pretreatment, which increases the process flow and is not conducive to economical production

Chinese patent CN102162073A discloses a method for preparing low-carbon and low-silicon cold-rolled hot-dip galvanized dual-phase steel for ultra-deep drawing. The invention adds a certain amount of precious metals Cr and Mo to the steel, and adopts a texture pretreatment process During production, the steel strips are prone to bonding during production with high texture pretreatment, which affects the shape and surface quality of the steel strip; at the same time, the process flow is long, which is not conducive to economical production

The texture pretreatment process requires sub-temperature annealing at a higher temperature before the final annealing. At present, bell annealing is commonly used. High annealing temperatures are prone to bonding between strips and affect the strip shape and surface quality; at the same time, the process flow Longer, not conducive to green and economical production

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