- The method of manufacture Zn-Ni alloyed electro-galvanized steel with superior image clarity

摘要

The present invention applies the EDM roll processing method using a specific processing mode for cold rolling and temper rolling when manufacturing Zn-Ni steel sheet for automobiles, applying the optimal elongation in temp rolling, and cold rolled steel sheet manufactured by such method After the Zn-Ni plating to control the cross-correlation of the surface roughness characteristics of the final product Zn-Ni steel sheet (Wca) ≤0.4, DOI 90% or more of the high-linearity Zn-Ni steel sheet is manufactured. In order to achieve the above object, the present invention applies the initial TCM # 5 roll to the electric discharge machining (EDT), and the processing mode is the capacity (-). By applying the electric discharge machining (EDT) furnace, the processing mode was set to the capacity (-), and the upright roughness was 2.0 μm and the downright roughness was 2.0 μm, respectively. In addition, the material adopts IF (Interstitial Free) steel, and the temper rolling elongation was set to 0.7 after numerous tests on the material thickness of 0.8mm. Current density control through inter-pole distance control in the hot dip galvanizing process and conductor rolls are replaced with robber rolls and managed at 20 ~ 24g / ㎡ based on double-sided weight, ultimately the wave shape (Wca) in cold rolling ) To control 0.4μm or less, and to control the WC of temper rolling 0.4μm or less, control the EG Zn-Ni wave size to 0.4μm or less and manufacture the high-strength Zn-Ni sheet with 90% or more DOI index. It is about a method.