Laboratory Studies of the Corrosion of Side-Seams in Soldered Tinplate Containers: Part II. The role of the solder and the electrolyte

Abstract

An accelerated simulated can corrosion test has been used to study a number of factors relevant to the corrosion of the soldered seam used in the fabrication of three-piece tinplate containers. Using oxygen headspace concentrations in excess of those normally found in cans, the effects of solder composition and electrolyte composition on the corrosion of 2%Sn/98%Pb solder in the presence of lacquered and unlacquered tinplate have been studied. It has been shown that changing the composition of the solder can affect the amount of lead dissolved during the tests, while the existence of electrical contact between the solder and tinplate has been shown to be important in some cases. Electrochemical measurements were made in order to rationalise the observed effects.