Zibo ShiNaite anti - corrosion Technology Co., Ltd
Contact: Wang Zhong
mobiles: 17663023308 15589303703
Address: Zibo City, Shandong Province Linzi District Qilu International Plastic City fine plasticized area 11-1
High-performance nickel-phosphorus alloy electroless plating process is a rapid development in recent years, a new surface protection and surface strengthening technology, has a wide range of applications. At present, electroless nickel-phosphorus alloy has been widely used in petrochemical, petroleum refining, electronic energy, automotive, chemical and other industries. Oil refining and petrochemical industry is its largest market, and with the understanding of the characteristics of its coating, its application is also more and more widely used mainly in the oil refining, petrochemical refrigeration equipment, and get Many users are recognized. The practical application can significantly improve the wear and corrosion resistance of the equipment, extend its life more than 3 times, the performance is better than the current use of organic coatings, but also for carbon steel, cast iron, nonferrous metals and other different substrates.
1, the principle of electroless nickel-phosphorus alloy
The main reaction is sodium hypophosphite reduction of nickel ions for the metal nickel, that is, in the aqueous solution of nickel ions and hypophosphite ion collision, due to nickel catalyst precipitation of atomic hydrogen, and atomic hydrogen and catalytic metal adsorption and make , The nickel ions in the aqueous solution are reduced to metal nickel to form a coating. In addition, the hypophosphite ions are reduced to active phosphorus due to the precipitation of atomic hydrogen on the catalytic surface, and Ni is combined with nickel to form a Ni-P alloy coating.
2, the characteristics of coating and technical indicators
(1) good coating uniformity
Amorphous Ni-P alloy coating is obtained by chemical deposition method, where the bath can be immersed in the site, any complex parts, can get a uniform coating. No external current, is amorphous homogeneous single-phase structure, there is no grain boundary, dislocations, and no chemical composition segregation, and to avoid the formation of the corner effect of plating defects. In addition, the coating is very dense also has a high finish.
(2) good adhesion to the coating
The coating produces a compressive stress (4 MPa) on the steel base, and the coating has a good thermal expansion coefficient, and therefore has excellent adhesion, typically 300-400 MPa.
(3) high hardness coating, excellent anti-wear properties
The coating has high hardness, low toughness and low thermal conductivity, conductivity, its tensile strength of more than 700MPa, and a lot of alloy steel is similar to the hardness and elongation of the coating are more than chrome plating, bending without cracks, but not suitable for repeated Bending and stretching and other severely deformed parts, the heat treatment hardness up to HV1100, but at 320 ℃ began to occur crystal transformation, wear resistance, corrosion resistance weakened.
(4) excellent corrosion resistance
As the coating is amorphous, there is no grain boundary, dislocations and other crystal defects, is a single uniform structure, easy to form galvanic corrosion, to determine its high corrosion resistance, Ni-P coating uniformity, tensile stress , Good density, in order to prevent the corrosion of the media to provide an ideal barrier. In the alkali, salt, high temperature oil, organic media and solvents, acid gases have corrosion resistance, proven by the practical application, especially for oil refining, petrochemical in the Cl-stress corrosion, high and low temperature H2S and naphthenic acid Corrosion has exceptional corrosion resistance.
|Media name||Wt％||Temperature (℃)||Ni-P alloy corrosion rate mm / y||1Cr18Ni9Ti Corrosion rate mm / y|
|Stress in coating of steel||<7|
|Density g / cm3||7.75||P content 8-10%|
|Melting point ℃||890||P content 7-9%|
|Resistivity μΩ • ㎝||0.9|
|Thermal conductivity w / m2||8|
|Tensile strength MPa||>700|
|Bonding force MPa||300－400||Low carbon steel, stainless steel for 160-200|
|Hardness HV||600－800||Treatment at 300 ° C up to 800-1100|
|Coating thickness μm||25－75|
|Heat resistance 700 ℃||Not skin, do not fall off|
|No porosity minimum thickness μm||15|
|Exterior||Similar to the silver white silver, soft colors, beautiful|
3, the scope of application
(1) petrochemical industry: cold replacement equipment, coil, injection pipeline, control valve pump, suction piston rod and so on.
(2) automotive and shipbuilding industry: engine shaft, anti-skid piston, air conditioner components, alternator heat sink, fuel tank, fuel injector drive thrust coil,
(3) textile industry: plastic mold, carved roller, guide roller, paper guide roller, storage tank, flat knitting machine, guide, needle, dryer, fabric blade, plastic cutter and so on.
(4) feed food industry: grill, bearings, canned production line equipment, pulleys, slicing devices, sorting machines, mixers and so on.
(5) other industries: hydraulic devices, clutches, pumps, shaft roller, drawing machine drums and so on.
Chemical anti-corrosion technology was first used in the petroleum and chemical industries. Ni-P alloy coating is amorphous structure, with excellent chemical inertness, can be effective against alkali, salt solution and sea water corrosion, anti-oil and a variety of hydrocarbon corrosion, combined with Ni-P coating wear resistance, so Formed its in the oil, natural gas development and petrochemical production in the protection of corrosion advantages, as the latest development of petrochemical equipment, a kind of anti-corrosion materials. In the Middle East, the United States and Germany, oil and natural gas extraction, in the pipeline, valve body, pump station corrosion protection, the technology has been widely used, and achieved remarkable results. China in the late eighties in the oil field industry development and application of the technology, on the basis of continuous practice to achieve a large area of heat transfer equipment, a comprehensive breakthrough in plating technology, greatly reducing costs and improve production efficiency and production capacity. At present, this relatively mature technology has been popularized in Daqing, Shengli and Zhongyuan Oilfields. It is used in the anti-corrosion of pipeline. In the petrochemical, chemical fiber, chemical fertilizer, salt, pharmaceutical, alkali, power generation, metallurgical coking and other industries Cold storage equipment, anti-corrosion field, can replace the stainless steel, but the cost of stainless steel 1/2. Application of the technology can improve the wear resistance and corrosion resistance of equipment to extend its service life of more than 3 times, the performance is better than the current use of organic coatings, and for carbon steel, cast iron, non-ferrous metals and other different substrates, Saving raw materials and energy, improve operating rate, significant economic benefits.