▎ 摘　　要

NOVELTY - Preparing battery steel case coated with metal layer on the surface, comprises (1) grinding surface of low-carbon steel strip, washing with alkali, pickling and washing, placing in nickel-iron plating solution, and electroplating to obtain nickel-iron metal layer as steel strip A, (2) carrying out surface magnetron sputtering of steel strip A to obtain nickel-iron-cobalt layer, which is steel strip B, the alloy target material is nickel-iron 10 at.%-cobalt 10 at.%, the process parameters are: the external magnetic field is 2-5 T, the sputtering power is 30-50 W, and the deposition rate is 0.03-0.05 nm/s, (3) placing the steel strip B in the nickel-iron-cobalt-phosphorus plating solution, electroplating to obtain the nickel-iron-cobalt-phosphorus metal layer, which is steel strip C, and (4) annealing the steel strip C, aging, and smoothing to obtain a battery steel strip, and punching to obtain final product. USE - The battery steel case is useful for batteries in new energy vehicles. ADVANTAGE - The method: sets the proportion of metal in each layer in a gradient by optimizing the plated metal layer, reduces thickness, improves stamping performance, thus improves the physical stability, compression resistance and corrosion resistance of the battery steel case. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for battery steel case prepared by above method.