Corrosion Processes in Carbonated Beverage Cans

Describes work undertaken to minimize occurrence of perforations and excessive iron pick up in carbonated beverage cans. Corrosion mechanism was one of attack on steel base of cans stimulated by reduction processes occuring at areas of exposed tin or other cathodic regions. Best solution was limiting galvanic current in the can through reducing corrosivity of beverage and control of metal exposure in the can. Short time test methods were devised to evaluate beverage corrosivity. A low air content was essential and control over other depolarizers in beverage led to lower corrosivities. Improvements made in organic coating systems and metal exposure in the side seam and double seam regions reduced corrosion currents so that perforations were no longer a problem and so that iron pick up was effectively reduced. 8.3.2