Effect of Paint Film Properties on the Corrosion Behavior of Pre-coated Stainless Steels

Abstract

The corrosion properties of stainless steel sheets pre-coated with many kinds of paints were examined by natural weathering test along with CASS test. The cross section of specimens exposed were studied with the microscope and the EPMA.
(1) In the case of uncoated stainless steel, its corrosion showed narrow pits.
(2) In the case that painted film had bad durability, corrosion of stainless steel showed wide pits under the film.
(3) In the case that painted film had good durability but poor adhesion, corrosion of stainless steel showed wide pits like crevice corrosion.
(4) In the case that painted film had good durability and good adhesion, no corrosion of stainless steel was found.