A Study of Nonprotective Rust Formation On Auto-Body Sheet Steel 560021
ALTHOUGH average car life has jumped in 30 years from 6½ to 13½ years, improvements in service life of body structures have not kept pace with increased durability of engines and other mechanical parts. Hence the growing interest in improving corrosion resistance of the sheet steels used in auto bodies.
This paper reports results obtained in cyclic humidity accelerated corrosion tests aimed at finding a cheap, easily formed sheet steel with better resistance against the sheltered corrosion which causes the most serious body damage. The test produces in 20 days the same kind of non-protective rust formed in years of outdoor exposure.
Since high-carbon steels, shown in the tests to be the most potent corrosion reducers, cannot be used in auto bodies because of their poor forming characteristics, efforts are now being directed toward finding a combination of elements that will produce the same results without a cost or forming penalty.