SEDL / STP / STP1239-EB / STP14918S

Corrosion Evaluation of Automotive Trim Material

Sabata, A
Research Engineer and Senior Staff Engineer, Armco Research and Technology, Middletown, OH

Drigel, GS
Research Engineer and Senior Staff Engineer, Armco Research and Technology, Middletown, OH

Cooper, TL
Development Metallurgist, Armco Inc., Coshocton, OH

Pages: 15    Published: Jan 1995

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Abstract

Bright annealed ferritic stainless steel is used as automotive trim material. A 20% Cr ferritic stainless steel gave adequate corrosion protection in chloride atmospheres. Both 17% Cr materials, 434 and 436, need a Cr flash for good corrosion protection. Electrochemical techniques such as Electrochemical Impedance Spectroscopy (EIS) and Cyclic polarization curves were used to evaluate the corrosion performance. The corroded samples were analyzed with Time-of-flight Mass Spectrometer (TOFSIMS) and Scanning Electron Microscope (SEM). The 20% Cr ferritic stainless steel performed better than the 17% Cr materials in all the tests. Some differences in the corrosion products were observed between the accelerated tests and outdoor exposures.