| 摘要 |
<p>PURPOSE:To improve rust preventiveness of an automotive body and to prevent deterioration in the properties of a spot-weld zone in the stage of manufacturing said body by providing a metallic plating stage between a degreasing stage and a painting stage in the stage for pressing and welding steel plates, etc. and assembling the same to the vehicle body then degreasing and chemically converting the same. CONSTITUTION:Steel plates for an automotive vehicle body such as cold-rolled steel plates or one-side painted steel plates, one side plated steel plates, etc. are blanked and are then pressed and spot-welded to the vehicle body by which the automotive vehicle body is assembled. After the vehicle body is degreased, the body is rinsed and is then plated with a metal such as Zn or Zn-Fe alloy, etc. by an electroplating method or vacuum deposition method. The vehicle body is then subjected to a zinc phosphate chemical conversion treatment then to rust preventive painting such as cationic electrodeposition painting or the like after rinsing. The exfoliation of the rust preventive painting layer is obviated and the life of the electrode chip in the stage of spot welding is extended. The deterioration in the corrosion resistance of the weld zone is thus prevented.</p> |
