ABSTRACT
For recent automobiles, higher performance under high-speed impact is demanded for the enhancement of passengers’ safety. Especially, in order to ensure the safety of the passengers under the lightweight and side collision, high strength material is applied to the upper part of the center pillar, and an even higher impact rigidity should be maintained than at the lower part. However, while car safety is extremely important, the appearance of the car is also important. Because of the coldrolled steel sheet process applied in car manufacturing, the center pillar is susceptible to corrosion, and needs to be painted for corrosion resistance in a variety of ways.
