Anti corrosion methods and implementation specifications for electric forklifts

1、 Material selection and process optimization

1. Application of corrosion-resistant materials

Metal materials: Galvanized sheet (zinc layer thickness ≥ 7 μ m), color coated sheet, and engineering plastics are preferred. For example, Linde forklifts use fiberglass engine covers, while Hangcha Group uses engineering plastics instead of traditional fiberglass in battery box covers to improve durability.

Non metallic materials: Fiberglass parts must meet weather resistance requirements (such as unsaturated polyester resin+alkali free glass fiber), and it is recommended to use engineering plastics (such as ABS+PC alloy) in mass production to reduce aging.

2. Metal plating and conversion coating

Galvanizing process: Key components (bolts, shafts) are coated with 7-10 μ m galvanized layer, while heavily corrosive environmental components (such as exhaust pipes) are coated with 20-25 μ m galvanized layer, and the coating type is marked according to GB/T 13911 standard.

Post processing requirements: Passivation treatment (such as trivalent chromium passivation) is required after coating to avoid color mixing affecting the appearance.

3. Coating system design

Coating thickness and type:

C3 environment (urban/light industry): epoxy primer (80 μ m)+polyurethane topcoat (80 μ m), with a total thickness of ≥ 160 μ m.

C4/C5 environment (chemical/marine): hot-dip galvanizing (≥ 70 μ m)+epoxy intermediate paint (120 μ m)+polyurethane topcoat (100 μ m), total thickness ≥ 320 μ m.

Functional coating: The battery box adopts acid resistant coating (such as phenolic resin paint), and the exhaust pipe adopts heat-resistant coating (organic silicon aluminum powder paint).

2、 Structural design and protection details

1. Avoid the accumulation of corrosive media

Ventilation and Drainage Design:

Install ventilation holes (diameter ≥ 10mm) and leakage holes in enclosed areas (such as battery boxes), with a bottom inclination angle ≥ 3 ° to facilitate the discharge of accumulated liquid.

The engine exhaust is discharged through the upper part of the counterweight to prevent high-temperature exhaust from directly contacting the frame.

Shape optimization: Drawing inspiration from the designs of Linde and Toyota forklifts, adopting a streamlined appearance to reduce water and dust accumulation (such as a rounded edge radius of ≥ 5mm for the roof protection frame).

2. Gap and heterogeneous metal treatment

Gap protection: The welding gap is sealed with polysulfide sealant, and the hydraulic cylinder piston rod is equipped with a dust cover (material: chloroprene rubber).

Electrochemical corrosion control: Zinc sacrificial anode (size: 50mm × 30mm × 3mm) is used at the aluminum steel connection, and anti rust oil (such as WD-40) is coated on the contact surface of dissimilar metals.

3. Protection of exposed parts

Electrical system: The connectors are equipped with built-in or added protective covers (IP65 rating), and the wiring is arranged away from corrosion sources (such as battery acid mist areas).

Process hole treatment: During oil tank shot blasting treatment, process holes (diameter ≥ 8mm) are opened to avoid liquid accumulation.

3、 Surface treatment and coating process

1. Pre treatment process

Sandblasting standard: Implement Sa 2.5 level (very thorough cleaning), surface roughness Ra 2.5-6.3 μ m, cleanliness meets ISO 8501-1.

Chemical treatment: The thickness of the phosphating film is ≥ 5 μ m, and the pH value of the passivation solution is controlled between 4.5-5.5.

2. Painting process

Electrophoretic coating: The key structural components are subjected to cathodic electrophoresis with a film thickness of 20-25 μ m. The salt spray test has passed for 1000 hours without any red rust.

Powder coating: Non exterior parts such as chassis are coated with epoxy powder coating, with a thickness of ≥ 120 μ m and better chemical resistance than liquid paint.

3. Repair process

Coating repair: Polish the blistering and peeling areas to Sa 2 level and apply epoxy repair paint, with a cumulative repair area of ≤ 5% of the original coating.

Connection processing: The blackening treatment of bolts, pins, and other components has been changed to Dacromet coating (thickness 6-8 μ m).

4、 Maintenance and upkeep standards

1. Daily maintenance

Battery maintenance:

Check the electrolyte density (1.28-1.30g/cm ³) monthly and clean the surface of acid mist residue (using 2% sodium bicarbonate solution).

After charging, the electrolyte level is 12.7mm away from the electrode plate, and distilled water is used for replenishment.

Hydraulic system: Replace hydraulic oil and filter element every 500 hours, and check the water content of the oil (≤ 0.1%).

2. Regular maintenance

Coating inspection: Use eddy current thickness gauges to measure coating thickness every quarter, and increase inspection frequency in key areas such as chassis and forks.

Seal replacement: Replace the hydraulic cylinder seal ring (material: polyurethane) every 2000 hours and check the integrity of the dust cover.

3. Environmental control

Humidity management: The warehouse humidity is controlled at 45% -65% RH, and rotary dehumidifiers are used in coastal areas (target humidity ≤ 60%).

Cleaning system: After operation, use a low-pressure water gun (pressure ≤ 0.3MPa) to wash the vehicle body to avoid salt/chemical residues. After washing, use compressed air to dry the gaps.

5、 Operating standards and training

1. Operational requirements

Prohibit hitting hard objects with forks to reduce surface coating damage.

Immediately rinse the forks after handling acidic and alkaline materials (rinse with clean water for at least 2 minutes).

2. Personnel training

Annual anti-corrosion operation training is conducted, covering practical skills such as coating repair, battery maintenance, and seal replacement.

Establish and maintain a record of each maintenance time, location, measures, and responsible person.

6、 Case verification

Hangcha Group: By optimizing the surface treatment process (such as thickening the phosphating film to 8 μ m), the corrosion resistance of the product has been improved by 30%, and the warranty period has been extended to 3 years.

Linde forklift: using special grade antifreeze and rust proof fluid, the corrosion rate of the cooling system is reduced to below 0.02mm/year, and maintenance costs are reduced by 40%.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment