1993-04-01

Galvanic Corrosion Behavior of Copper and Stainless Steel in Heat Exchanger Environments 931109

Vehicle heat exchangers are exposed to a number of aqueous environments ranging from inhibited coolants to seawater. Frequently, the design of the heat exchanger results in a galvanic couple between copper and a stainless steel. This couple can either prevent or promote pitting and crevice corrosion of the stainless steel member. This paper demonstrates the use of electrochemical corrosion measurement techniques to predict this behavior. Stainless steels which have acceptable, marginal and unacceptable resistance to localized corrosion when coupled to copper in aggressive environments are described.
Potentiodynamic polarization curves for a variety of stainless steels were measured in artificial seawater to determine their pitting and critical protection potentials. Mixed potential measurements for these alloys galvanically coupled to copper were then made to predict the localized corrosion behavior of the stainless steel. The analysis of localized corrosion behavior based on potential measurements was augmented by measurements of zero resistance ammeter currents. Mass change data and visual observations were used to confirm the results of the electrochemical measurements. The effect of temperature on localized corrosion of the stainless steels coupled to copper was also investigated.
Heat exchangers can be designed with copper clad steel or stainless steel as a self brazing material. The techniques described in this paper can be used to determine the corrosion resistance of these materials in heat exchanger environments where there is little service experience.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Corrosion of Copper/Brass Radiators - Corrosion Mechanisms - Prevention Actions

920180

View Details

TECHNICAL PAPER

A Study of Extension of Engine Coolant Life Using Low Phosphate Organic Acid Inhibitors

2003-01-2023

View Details

TECHNICAL PAPER

Characterization of Film Formation on Magnesium Alloys due to Corrosion in Engine Coolants

2008-01-1155

View Details

X