Bearing salt spray corrosion high phosphorus chemical nickel processing technology

⑴ uniform coating thickness, the degree of dispersion of the electroless plating solution is close to 100%. Plating itself is an autocatalytic redox process, as long as the catalytic base can come into contact with the solution plating, is almost a copy substrate shape, to the extent copying, not the same as the plating occurs due to the uneven distribution of the power line The coating thickness caused by uneven. ⑵ Electroless plating not only on the metal surface, through the activation of a special, sensitization processing may be carried out on non-metallic surfaces. ⑶ plating equipment is simple, requires no power and anode, as long as the temperature, pH value and reasonable conditions of process parameters, the part to be plated is immersed in the bath can be. ⑷ chemical plating adhesion and corrosion performance are superior to plating. Certain chemical plating has special physical and chemical properties. ⑸ high hardness, wear resistance, chemical plating nickel layer after heat treatment hardness of Hv1100, tool and die life increased after nickel is generally more than three times. ⑹ strong corrosion resistance, nickel plating in acid, alkali, salt, ammonia and water and other media have good corrosion resistance, corrosion resistance than stainless steel. ① hypophosphite as reducing agent, since phosphorus precipitation occurs co-deposition of nickel phosphorus, so phosphorus electroless nickel layer was nickel-phosphorus alloy coating dispersion state of the coating phosphorus content of 1% ~ l5 % control phosphorus content of the nickel phosphorus plating obtained dense, non-porous, corrosion resistance far superior to nickel plating. When borohydride or aminoboranes as a reducing agent, electroless nickel plating layer is a nickel-boron alloy coating, the boron content of 1% to 7%. Only hydrazine as a reducing agent to obtain the coating layer is pure nickel, nickel content of up to 99.5%. ② high hardness, good wear resistance. Nickel plating layer hardness is only l60 ~ 180HV, and electroless nickel plating layer hardness is generally 400 ~ 700HV, after appropriate heat treatment can be further increased to close to or even exceed the hardness of chromium, so good wear resistance, more rare electroless nickel plating is both good corrosion and wear resistance. ③ chemical stability, good coating adhesion. In the atmosphere and in other media, nickel plating chemical stability than the chemical stability of the nickel plating layer. In combination with a conventional steel, copper and other substrate well, bonding strength of not less than a nickel plating layer and the adhesion substrate. ④ Because phosphorus electroless nickel plating heat treatment after different processes (B) the amount of different and plating, physical and chemical properties of nickel plating layer, such as hardness, corrosion resistance, wear resistance, electromagnetic properties have a variety of changes, Other plating is rare. Therefore, electroless nickel plating for industrial applications and process design diversity and special characteristics.