The invention discloses an
electroless nickel pre-plating and hot post-galvanizing method for controlling the
coating thickness of the
silicon-containing reactive steel, which means first performing
electroless nickel plating and then hot dip galvanizing on a
silicon-containing reactive steel part. The
electroless nickel pre-plating and hot post-galvanizing method comprises the following processes: (1) doing pretreatment on the surface of the
silicon-containing reactive steel part before
electroless nickel plating; (2) carry out
electroless nickel plating on the surface of the silicon-containing reactive steel part, wherein, the
nickel salt used is NiSO4 x 6H2 O, the
reducing agent is NaH2PO2 x H2O, and the complexing agent is C6H5Na3O7 x 2H2O; (3) after
drying the silicon-containing reactive steel part undergoing
electroless nickel plating, conducting hot dip galvanizing on the reactive steel part. The electroless
nickel pre-plating and hot post-galvanizing method for controlling the
coating thickness of the silicon-containing reactive steel has the advantages of effectively controlling the
coating of the hot galvanized silicon-containing reactive steel from thickening exceedingly, thus obtaining a coating with appropriate thickness,
smooth surface and good adhesivity, consuming less
nickel, and accomplishing the goal of preventing the hot galvanized coating of the silicon-containing reactive steel from excessively thickening by electrolessly plating a
nickel coating with a thickness of 3 to 4 microns on the reactive steel part. Moreover, the pre-plate
nickel coating can prevent the iron in steel part from dissolving in the
zinc bath, thus greatly reducing the formation amount of
zinc dross, and reducing the loss of
zinc.