Straight carbon steel surface coverage Ni-Zn-Mn-P electroless plating composite deposite and plating bath
Technical field
The present invention relates to a kind of straight carbon steel surface chemical plating Ni-Zn-Mn-P compound plating preparation method of covering layer that is used for, specifically, relate to the coating and the plating bath of straight carbon steel surface chemical plating.
Background technology
Chemical plating Mi-P alloy coating is with its good wear-resisting, anti-corrosion, magneticshielding property and the plating that is applicable to various materials (comprising non-metallic material) complicated shape; Industry such as Aeronautics and Astronautics, electronics, oil and chemical industry have been widely used in; Owing to the meliority of chemical plating technology itself and reaching its maturity of chemical plating nickel technology, its range of application in China is more and more wider in recent years.Be accompanied by industrial fast development, material property is had higher requirement, the chemical nickel phosphorus plating binary alloy far can not satisfy the etch-proof requirement of modern industry; Therefore on chemical plating nickel-phosphorus alloy plating bath basis, developed chemical plating Ni-Gu-P again, Ni-Cr-P, Ni-Co-P; Ni-Mo-P, Ni-Fe-P, Ni-W-P; Ternary alloy coatings such as Ni-Zn-P, their over-all properties (especially solidity to corrosion) is more excellent than Ni-P alloy, thereby receives much attention.
But general chemical plating coating is a cathode type coating, is applied to the surface anticorrosion in the container, does not generally allow to occur the space, otherwise can quicken the container local corrosion, cause perforation, and electroless plating itself is difficult to thoroughly eliminate the generation in space.This patent is on the basis of summing up electroless plating ternary alloy successful experience; In Electroless Plating Ni-Zn-P alloy electroplating bath, add manganous sulfate, successfully developed a kind of straight carbon steel surface chemical plating Ni-Zn-Mn-P composite deposite that is used for, the crystallization of gained coating is careful; Light is level and smooth; Solidity to corrosion and ductility are good, and hydrogen embrittlement is low, internal stress is little, and integrated performance index is superior to electroless plating binary alloy and corresponding ternary alloy coating.Key is that this patent gained coating moves with respect to the plating nickel-phosphorus alloy current potential is negative; The solidity to corrosion and the wear resistance of straight carbon steel have been improved; (be this coating with respect to the potential difference of matrix potential difference less than binary plating nickel-phosphorus alloy and matrix; When there is defective in the surface, less) to the influence that the whole antiseptic property of coating produces.
Summary of the invention
The technical problem that the present invention will solve provides a kind of straight carbon steel surface chemical plating Ni-Zn-Mn-P compositive lining cap rock that is used for; It is simple that this method prepares process; Production operation safety; Production cost is low, and prepared coating not only possesses good solidity to corrosion and realizes effective anticorrosion purpose, and satisfies ornamental requirement.
The present invention has mainly studied the influence rule of processing parameter to Coating composition structure, electropotential, contains Ni
2+, Mn
2+, Zn
2+, H
2PO
2-Deng the plating bath of composition such as main salt, complexing agent, additive and factors such as PH and temperature to the influence of matrix surface deposition process, the influence of the variation of composite deposite corrosion potential etc.Through above-mentioned research and experiment, finally obtain to have the composite deposite of excellent corrosion resistance at specimen surface.
Technical scheme of the present invention is following:
A kind of straight carbon steel surface coverage Ni-Zn-Mn-P electroless plating composite deposite of the present invention, thickness of coating is 8-15 μ m, hardness 190-350HV, compares the negative 0.1-0.3V of current potential with pure plating nickel-phosphorus alloy.
Straight carbon steel surface coverage Ni-Zn-Mn-P electroless plating composite deposite preparation method of the present invention; Mainly be the configuration of plating bath: single nickel salt 20-30g/L, zinc sulfate 10-30g/L, manganous sulfate 10-40g/L, inferior sodium phosphate 30-60g/L, sodium acetate 5g/L and Trisodium Citrate 15g/L, use ammoniacal liquor or sodium hydroxide to regulate pH 90 ℃ of temperature and be 9-10.
Adopt the sanding and polishing-cleaning-oil removing-rust cleaning-cleaning-activation-plating-cleaning-cleaning-aftertreatment of common workpiece, can obtain straight carbon steel surface coverage Ni-Zn-Mn-P electroless plating composite deposite; Only adopt a plating, the plating process is simple.
Adopt straight carbon steel (like Q235) the surface chemical plating Ni-Zn-Mn-P compound plating preparation method of covering layer that is used for of the present invention, the erosion resistance of composite deposite in 3.5%NaCl solution characterizes with Fig. 3, compares the negative 0.1-0.3V of current potential with pure plating nickel-phosphorus alloy.Its power spectrum and microscopic appearance are as depicted in figs. 1 and 2.
Fig. 1 explanation: spectrogram is handled: do not have uncared-for peak; Processing option: all elements (normalization method) through analyzing; Multiplicity=4; Standard model:
C CaCO
3?1-Jun-1999?12:00?AM
O SiO
2 1-Jun-1999?12:00?AM
P GaP ?1-Jun-1999?12:00?AM
Mn?Mn 1-Jun-1999?12:00?AM
Fe?Fe 1-Jun-1999?12:00?AM
Ni?Ni 1-Jun-1999?12:00?AM
Zn?Zn 1-Jun-1999?12:00?AM
The invention has the beneficial effects as follows:
The present invention adopts the method that changes Coating composition and structure, has increased the coating erosion resistance, and in industrial production, coming into operation has a extensive future.The crystallization of gained coating is careful, and light is level and smooth, and integrated performance index is superior to electroless plating binary alloy and corresponding ternary alloy coating.Owing to carry out processing condition such as temperature, pH value, main salt to Coating composition, hardness, corrosion potential and corrosion proof experimental study, proposed the technical recipe system of optimizing.Draw the condition of surface that has changed material through the surperficial coating that forms of the straight carbon steel of electroless plating of the present invention; Make the corrosion potential of material move to negative direction with respect to the nickel and zinc phosphorus alloy; When corrosion takes place; Less with the matrix potential difference, can effectively protect matrix, it is better than former cathodic electrodeposition coating to tackle the effect in space especially.Stable, easy and simple to handle, the low cost and other advantages of this technical matters simultaneously.Plating bath convenient configuration of the present invention can repeat repeatedly to use, and Financial cost is low, easy handling.
Description of drawings
Fig. 1 power spectrum: coating is done energy spectrum analysis, obtain the composition of coating, contain our element of applying such as zinc, manganese.
Fig. 2 coating metallograph: under light microscopic, observe the surface of coating, see that plating defect is less.
Fig. 3 Nyquist figure: matrix and coating are done the electrochemical impedance measurement respectively, obtain both capacitive reactance arcs, Rp:233.7 ohm of matrix, Rp:1058 ohm of coating.The big more solidity to corrosion of polarization resistance is good more.Among the figure, the 1st, coating, the 2nd, matrix.
Embodiment
Through concrete embodiment the present invention is made further detailed description below:
Following examples can make those skilled in the art more comprehensively understand the present invention, but do not limit the present invention in any way.
Embodiment 1
The composition of plating bath: 90 ℃ of single nickel salts (20g/L), zinc sulfate (30g/L), manganous sulfate (20g/L), inferior sodium phosphate (60g/L), sodium acetate (5g/L), Trisodium Citrate (15g/L), temperature, using ammoniacal liquor to regulate pH is 9.Through common sanding and polishing-cleaning-oil removing-rust cleaning-cleaning-activation-plating-cleaning-cleaning-aftertreatment, to obtain thickness be 8 μ m, more than the hardness 196HV, the coating of potential difference-0.216V.
Embodiment 2
The composition of plating bath: 90 ℃ of single nickel salts (30g/L), zinc sulfate (30g/L), manganous sulfate (30g/L), inferior sodium phosphate (60g/L), sodium acetate (5g/L), Trisodium Citrate (15g/L), pH 9-10, temperature, 90 ℃ of temperature, using ammoniacal liquor to regulate pH is 10.Through common sanding and polishing-cleaning-oil removing-rust cleaning-cleaning-activation-plating-cleaning-cleaning-aftertreatment, to obtain thickness be 10 μ m, more than the hardness 211HV, potential difference is-and the coating of 0.232V.
Embodiment 3
The composition of plating bath: 90 ℃ of single nickel salts (30g/L), zinc sulfate (25g/L), manganous sulfate (40g/L), inferior sodium phosphate (60g/L), sodium acetate (5g/L), Trisodium Citrate (15g/L), pH 9-10, temperature, sodium hydroxide adjustment pH value are 9 to reach processing requirement.Through sanding and polishing-cleaning-oil removing-rust cleaning-cleaning-activation-plating-cleaning-cleaning-aftertreatment, obtain thickness for (15 μ m), more than the hardness (350HV), potential difference (coating 0.3V)
Embodiment 4
The composition of plating bath: 90 ℃ of single nickel salts (24g/L), zinc sulfate (10g/L), manganous sulfate (10g/L), inferior sodium phosphate (60g/L), sodium acetate (5g/L), Trisodium Citrate (15g/L), pH 9-10, temperature, sodium hydroxide adjustment pH value are 10 to reach processing requirement.Through sanding and polishing-cleaning-oil removing-rust cleaning-cleaning-activation-plating-cleaning-cleaning-aftertreatment, obtain thickness for (8 μ m), more than the hardness (190HV), potential difference (coating 0.1V)
Embodiment 5
The composition of plating bath: 90 ℃ of single nickel salts (25g/L), zinc sulfate (25g/L), manganous sulfate (30g/L), inferior sodium phosphate (50g/L), sodium acetate (5g/L), Trisodium Citrate (15g/L), pH 9-10, temperature, ammoniacal liquor adjustment PH are 9.5 to processing requirement.Through sanding and polishing-cleaning-oil removing-rust cleaning-cleaning-activation-plating-cleaning-cleaning-aftertreatment, obtain thickness for (10 μ m), more than the hardness (223HV), the potential difference (coating of 0.242V.
Embodiment 6
The composition of plating bath: 90 ℃ of single nickel salts (25g/L), zinc sulfate (25g/L), manganous sulfate (30g/L), inferior sodium phosphate (30g/L), sodium acetate (5g/L), Trisodium Citrate (15g/L), pH 9-10, temperature, using sodium hydroxide adjustment pH value is 10 to reach processing requirement.Through sanding and polishing-cleaning-oil removing-rust cleaning-cleaning-activation-plating-cleaning-cleaning-aftertreatment, obtain thickness for (8 μ m), more than the hardness (204HV), potential difference (0.135V) coating.
Although combine accompanying drawing that the preferred embodiments of the present invention are described above; But the present invention is not limited to above-mentioned embodiment, and above-mentioned embodiment only is schematically, is not restrictive; Those of ordinary skill in the art is under enlightenment of the present invention; Not breaking away under the scope situation that aim of the present invention and claim protect, can also make the concrete conversion of a lot of forms, these all belong within protection scope of the present invention.