A chemical treatment applied to ferrous metals to
improve their corrosion resistance. The process is based
on a manganese phosphate solution which produces a
fairly thick coating. This can subsequently be painted or
impregnated with oil. Patenting A heat treatment process
often applied to high carbon wire. The steel is heated to
a suitable temperature well above the transformation
range, followed by cooling in air or a bath of molten lead
or salt. A structure is produced suitable for subsequent
cold drawing and which will give the desired mechanical
properties in the finished state.