Nickel plating usually do before chromium planting as the preliminary coating in order the surface more smooth and easier to plated by chrome. Nickel plating also usual as the self coating on the metals surface for many purposes.
A Nickel bath recommended for producing hard nickel deposit has been used for applying nickel on the surface of rolls, the salvaging of worn on mismachined, and current density is necessary in this bath to maintain the desired hardness value. The tensile strength increase and the ductility decreases with an increase of pH and a decrease in temperature. The deposit has a rather low annealing temperature and will not retain full harness above 232 oC. Disadvantages of this hard nickel bath are a greater tendency to form nodules and trees than the chloride or Watt bath and a high internal stress in the deposits which can cause sporadic cracking.
In almost all cases, it is much better and much simpler to use class I addition agents, the stress reducers, in Watts or sulfamate baths to obtain the desired harness reducers, in Watts or sulamate baths to obtain the desired hardness without tensile stress. The stess reducers such as saccharin, p-toluena sulfonamide, sodium m-benzene disulfonate, sodium 1,3,5-naphtalene trisulfonamide, o-slfobenzaldehyde, can introduce about 0.03% sulfur as sulfide in the plate, are most generally used.
A Nickel bath recommended for producing hard nickel deposit has been used for applying nickel on the surface of rolls, the salvaging of worn on mismachined, and current density is necessary in this bath to maintain the desired hardness value. The tensile strength increase and the ductility decreases with an increase of pH and a decrease in temperature. The deposit has a rather low annealing temperature and will not retain full harness above 232 oC. Disadvantages of this hard nickel bath are a greater tendency to form nodules and trees than the chloride or Watt bath and a high internal stress in the deposits which can cause sporadic cracking.
In almost all cases, it is much better and much simpler to use class I addition agents, the stress reducers, in Watts or sulfamate baths to obtain the desired harness reducers, in Watts or sulamate baths to obtain the desired hardness without tensile stress. The stess reducers such as saccharin, p-toluena sulfonamide, sodium m-benzene disulfonate, sodium 1,3,5-naphtalene trisulfonamide, o-slfobenzaldehyde, can introduce about 0.03% sulfur as sulfide in the plate, are most generally used.