GB181781A - A new or improved process for coating iron or steel articles with lead with or without other metals - Google Patents

Abstract

181,781. Jackson, W. J. Mellersh-, (Leadizing Co.). Feb. 19, 1921. Coating.-Iron or steel articles are coated with lead by immersion in a heated aqueous solution of lead acetate containing acetic acid. The solution contains approximately 40-50 per cent by weight of lead acetate, and 5 per cent cr more of acetic acid, and is maintained at a tempera ture between 160-180‹ F. The coated articles, on removal from the bath, are washed to remove iron acetate and so to prevent rusting. To increase the density of the coating and render it smoother, the coated article may be immersed in a bath of zinc chloride and sodium chloride, preferably in the proportions of SO per cent and 20 per cent respectively, maintained at a temperature of approximately 650‹ F. In treating malleable-iron castings or other articles with a somewhat rough surface, about 5 per cent of tin chloride is. added to the bath, the proportion of sodium chloride being correspondingly reduced. A. thin film of tin is deposited on the lead coating. The lead coating process, either with or without the subsequent treatment in the zinc chloride bath, may be employed for coating iron or steel articles prior to the electrodeposition thereon of a coating of copper or nickel. The process may also be employed for coating billets for use in the manufacture of cold-drawn steel tubes, the lead serving for lubricating the billets for the drawing operation and giving the finished tubes a highly polished rust-proof surface. Except where the billets are to be subjected to a large number of passes, the usual lubrication or " doping " may be dispensed with. The coating process may also he utilized in connection with 'blanks to be employed in stamping operations.