Seamless cylinder shell construction

摘要

A method of forming a seamless cylinder shell in which a layer of nickel is electroplated on a steel sheet so that a composite sheet is formed. The composite sheet is then preferably cut into a circular blank before further processing. The circular blank is subjected to an oxalic acid pretreatment for the nickel side and a zinc phosphate pretreatment for the steel side to retain a lubricant on the two opposed surfaces thereof and is thereafter lubricated with the lubricant. The circular blank is preferably cupped, relubricated, and drawn into the seamless cylinder shell. The seamless cylinder shell can be finished into a seamless gas cylinder by spinning one end of the cylinder into a cylinder head, internally threading the formed cylinder head, and then heat treating the cylinder.