Two easily-performed laboratory tests have been developed which give results correlating with internal corrosion performance of plain electrolytic tin plate containers. One, the “rate of pickling” test, measures a permanent surface property of the steel arising in the annealing operation. The other, the “iron solution” test, measures the effect of certain factors governing the nature of the steel surface prior to electrotinning and to some extent the effect of the plating operation itself.
Tin plate manufacturers have used these tests as guides in improving the corrosion resistance of their product. The described tests, however, are not entirely adequate to account for all of the existing variations in corrosion performance believed to be related to steel surface characteristics. Additional work is required. 7.5.2
