Cold-rolled steel sheet for battery case with tensile strength of 320 MPa and production method of cold-rolled steel sheet

Abstract

The invention discloses a cold-rolled steel sheet for a battery shell with the tensile strength of 320 MPa and a production method of the cold-rolled steel sheet. The technical problems that the cold-rolled steel sheet for the battery shell with the thickness of 0.30-0.50 mm and the tensile strength of 320 MPa is unstable in performance and high in production cost are mainly solved. The invention provides a cold-rolled steel sheet with tensile strength of 320 MPa for a battery case. The cold-rolled steel sheet comprises the following chemical components in percentage by weight: 0.015-0.025% of C, less than or equal to 0.03% of Si, 0.10-0.20% of Mn, less than or equal to 0.015% of P, less than or equal to 0.015% of S, less than or equal to 0.0035% of N, 0.02-0.05% of Al, 0.001-0.002% of B and the balance of Fe and inevitable impurity elements. The tensile strength Rm of the cold-rolled steel plate is 320-370 MPa, the longitudinal yield strength range is smaller than 10 MPa, and the performance of the steel plate is stable.

Description

technical field [0001] The invention relates to a cold-rolled steel plate, in particular to a cold-rolled steel plate for a battery case with a tensile strength of 320MPa and a production method thereof, belonging to the technical field of iron-based alloys. Background technique [0002] With the rapid development of new energy electric vehicles in China, the demand for power batteries is increasing day by day. The steel battery case plays an important role in ensuring the quality and safety of the battery. The production of the battery case adopts multi-pass high-speed stamping, which has high requirements on the formability, strength, uniformity and surface quality of the material to ensure Battery safety. [0003] The current composition design of battery shell steel generally adopts ultra-low carbon steel, which contains microalloys such as niobium and titanium, and the production cost is high. In addition, ultra-low carbon steel has low strength and weak impact resista...

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Problems solved by technology

[0011] The purpose of the present invention is to provide a cold-rolled steel plate for battery cases with a tensile strength of 320MPa and its production method, which mainly solves the unstable performance and production cost of cold-rolled steel plates for battery cases with a thickness of 0.30-0.50mm and a tensile strength of 320MPa. High technical problem; the cold-rolled steel plate of the present invention has good uniformity of mechanical properties along the length direction, meets the requirements of high-speed stamping and pressing of the shell for the cold-rolled steel plate strength uniformity of the battery case, and the production cost of the cold-rolled steel plate is low; Bell annealing or production with ultra-low carbon steel components lead to long production cycle, high energy consumption, poor performance uniformity of cold-rolled steel sheets along the length direction, and difficult to meet the technical problems of high-speed stamping shells for steel sheet strength uniformity

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