Cylinder piston rod uses nickel-cobalt-iron alloy instead of chrome plating

The realization of the “cleaning of nickel-cobalt-iron alloys” is a major breakthrough in the reform of the electroplating process. Whether it is sustainable development of modern industry or environmental protection can play a major role in promoting, it is expected to fully replace the hard chrome plating.

1, plating: 0.03-0.05mm (unilateral), plus plating up to 0.1-0.2mm;

2, hardness: before heat treatment (after plating) HV650-750, hardness fluctuation range; after heat treatment HV850-1200;

3, surface gloss: similar to the stainless steel color, weak dark, feel more delicate than chrome plating;

Surface roughness: up to Ra0.2 after super-finishing, the surface color of the coating is different from that of the hard chromium plating, which is slightly inferior to the hard chrome plating;

4, after the salt spray test, the corrosion resistance is better than the chrome plating;

5. After the assembly of the piston rod, the coefficient of friction of the coating and the seal in the movement is close to that of the chromium layer;

Nickel, cobalt and iron alloy plating process analysis:

1. Energy-saving: Electroplating process of nickel-cobalt-iron alloy: electrolytic degreasing → cleaning → deionized water cleaning → activation → washing → electroplating → cleaning and recycling → cleaning → washing

The electroplating process route is generally similar to the hard chrome plating process. The current density during electroplating is 7 amps per square decimeter, which is much less than that of the hard chrome plating, and is about 1/10 to 1/20 of the hard chrome plating. Plating requires higher hardness than hard chrome plating.

2, environmental protection:

The nickel-cobalt-iron alloy coating has no hexavalent chromium in the whole process, mainly nickel salt and cobalt salt. As long as the iron salt slightly processes the gas generated during electroplating, and the gas contains no irritating amine, the environmental protection treatment cost is small. .

3, processing after plating:

A. Usually, as long as a superfinishing process (such as polishing or oil stone honing) is performed after the electroplating of chromium, the heat treatment process may be performed after the nickel-cobalt-iron alloy plating to increase the microhardness thereof. That is heated to 240 °C ± 20 °C, heat for about 30 to 60 minutes; will not cause the body metal hardness becomes soft.

B. Grinding processability: horizontal rod size Φ45-0.02-0.06 uses the same cylindrical honing machine to process the plating: nickel-cobalt-iron alloy plating is less than hard chrome plating to get rid of 3-10μm;

C. Improvement of the precision of the substrate: The nickel-cobalt-iron alloy is a transparent coating. When the matrix material has defects within the allowable range of strength, the surface is still clearly visible, and sometimes the plating defects are mistakenly considered.

Instead of chrome plating process prospects: Advantages: energy saving, power saving, environmental protection, slightly lower cost than hard chrome plating Disadvantages: A, temperature 240 °C ± 20 during heat treatment;

B. The hardness can be increased by heating, and heating adds a process. In the process of heating and clamping, it is easy to produce bumps, and the heating and quenching are easily deformed.

Suggested improvements: The hardness after plating is not comparable to that of hard chrome without heat-quenching.

Generation of chromium-plated nickel-cobalt-iron

1, high hardness, good corrosion resistance and wear resistance, equivalent to or better than the chrome plating performance;

2. The pollution is very light, there is no state-one class control of emissions; the process has a mature clean production program, the use of clean water recycling, wastewater discharge total zero discharge "technology.

3, the plating solution dispersion capacity and coverage better than the chrome plating; deposition rate of about 60μm / h; 4, there is a complete plating process and different materials on the deplating process;

5, good leveling ability, plating thickness of 3mm, the coating is still very bright;

6. The utilization rate of nickel-cobalt-iron alloy electroplating process is more than 95%, the current efficiency is more than 95%, the production cost is lower than that of chromium plating process, the cost of nickel-cobalt-iron alloy electroplating technology is the lowest, the comprehensive performance of the coating is medium, and advanced automatic control is combined. System, an environmentally friendly electroplating technology that can completely clean production during the production process. It does not cause harm to the surrounding environment. Therefore, the realization of the "cleaning of nickel-cobalt-iron alloys" is a major breakthrough in the reform of the electroplating process. Whether it is sustainable development of modern industry or environmental protection can play a major role in promoting, it is expected to fully replace the hard chrome plating.