After the appearance of brush plating technology, more and more maintenance workers began to use brush plating technology to repair hydraulic rods and cylinders. Due to the adoption of brush plating maintenance technology
The process is simple, low cost and high production efficiency, and the metal bonding between the repair layer and the substrate can be realized at room temperature. Therefore, in many
Among modern maintenance methods, brush plating repair technology has gradually become the main method to repair the hydraulic system of construction machinery.
1。 Brush plating process of chromium-plated hydraulic rod
Mechanical shaping (expanding defects to be suitable for good contact between electroplating pen and electric grinding head) → electric cleaning → water washing → oxide film removal (various activation treatments).
→ Activation of chromium surface → Nickel plating on the bottom of chromium surface → Water washing → High-speed thick copper pit filling (electroplating capacity above 3mm) → Mechanical grinding (grinding to smooth transition) →
Electric cleaning → water washing → chromium surface activation → nickel plating on chromium surface → water washing → wear-resistant surface layer → water washing → mechanical grinding → surface polishing.
2。 Maintenance process description
The hydraulic rod with uniform wear is easy to repair, and the more effective method is to grind off the electroplated layer (mainly chrome-plated layer) on the surface first. If directly
It is difficult to ensure the bonding force when electroplating chromium-plated surface. Although some people use anodic etching to activate chromium plating layer, it is often difficult to ensure activation.
Effect, repair reliability is not high), and then according to the conventional electroplating repair process for electroplating repair.
It is used to repair local injuries with large depth (millimeter level) and small area, such as pit injury, electric injury and collision injury. , displayed in the work site.
Complex, not suitable for electroplating repair method. FJY series fast ultra-thick brush plating repair technology is the best choice to solve this kind of problem, and its technology is called
As follows:
Mechanical shaping: polish the part to be repaired with an electric grinding head to make it smoothly transition into an arc, so as to ensure that the electroplating pen can touch the bottom of the pit.
Electric cleaning: the function of electric cleaning is to remove oil stains from the surface of the workpiece. In order to prevent oil pollution of electroplating solution, all places where electroplating solution may flow should be
It's time for electric cleaning. The net area of electricity can be larger, and the number of times can be more than twice, so as to ensure that the work is completed after this step.
Oil stains on parts can be completely removed.
Activation: The materials of hydraulic rods are mostly quenched and tempered carbon structural steel. Generally, No.2 activation and No.3 activation are used to remove oxygen from the steel surface.
Chemical film, cementite and free carbon (supersaturated carbon). Removal of oxide film on chromium plating layer by omni-directional chromium surface activating solution. if
The chrome-plated surface has not been treated with chromium surface activating solution, and the combination between the coating and the chrome-plated layer is not firm, so it is difficult to achieve flatness when polishing after plating.
Smooth transition. Rough boundary will scratch the oil seal when using.
Chrome plated bottom nickel: the function of chrome plated bottom nickel is to brush a firmly bonded bottom layer at the repair site (its function is the same as that of laying foundation during construction).
Similarly, only when the foundation is firmly laid can the building be stable), and the time for nickel plating on the chrome-plated surface should not be too long to electroplate the surface.
Uniform bright white is appropriate. If the bottom layer is gray (or dark gray), the bottom layer should be polished and pretreated again.
And nickel plating on the bottom.
Filling the pit with high-speed thick copper: the depth of local damage of hydraulic rod is generally between 0.5 and 3 mm. Fill the pit with high-speed ultra-thick and high-accumulation thick copper and brush plating time.
About 0.5 ~ 1 hour (generally, the depth of 1mm can be filled in 15~20 minutes).
Mechanical grinding: Use copying abrasive tools to grind the brush plating surface from coarse to fine, so as to achieve smooth transition and tolerance requirements.
Wear-resistant surface coating: In order to improve the surface hardness and corrosion resistance, nickel and its alloy are generally used as the surface coating. Because the surface layer is covered
There is a copper layer and a chromium layer on it, so before plating the surface layer, chromium surface activation and nickel plating are still needed.
Surface polishing: The function of surface polishing is to finish the brush plating surface, and polish the brush plating surface with fine sandpaper dipped in polishing paste, so that the surface can achieve mirror luster.
Polishing has dual functions: one is to improve the sealing performance, and the other is to prevent the oil seal from wearing.
According to the brush plating method recommended in this paper, the chrome-plated hydraulic rod and cylinder are repaired, and the effect is equivalent to that of new parts.