Scanning Electron Microscopy (SEM) and X-Ray Microanalysis (EDS) have been used to investigate rapid detinning, pitting corrosion and cosmetic corrosion in plain tin plate food cans and pitting corrosion, underenamel corrosion, enamel flaking , sulfide black corrosion and stress corrosion cracking in enamelled food cans.
Through the use of SEM - EDS it was determined that (SnL a /FeK a) Y2 X -ray line intensities arc proportional to the tin coating weight on tinplate. The method was applied to a rapid detinning problem in canned grapefruit sections. The cause of the early corrosion failure was found to be reversed tinplate. An early pining corrosion failure in apple sauce packed in plain tinplate cans was re lated to use of tinplate sensitive to pin ing corrosion in combination with a product contain ing oxygen and nickel as corrosion accelerators. An internal rust ing cosmetic corrosion problem present on the inside tinplate ends of canned mushrooms was caused by exposed steel at lightly tinned surface ridges of tinplate reacting with moisture and oxygen in the product. An early pitting corrosion problem in carrots packed in enamelled cans was related to excessive metal exposure at the side seam weld and at various a reason the can body . An underenamel corrosion and enamel flaking problem in canned pet food was caused by the inadvertent use of black plate instead of tin free steel. A sulfide black corrosion problem on the tin free steel ends of canned minced clams may be related to enamel fracture . A stress corrosion cracking problem in canned pet food may be related to can coating integrity and copper residues in the product.
Charbonneau, James E.
"Application of Scanning Electron Microscopy and X-ray Microanalysis to Investigate Corrosion Problems In Plain and Enamelled Three Piece Welded Food Cans,"
2, Article 8.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol10/iss2/8