The main materials for emulsion cranes (cranes used in emulsion environments) need to balance structural strength and emulsion corrosion resistance. The core materials include the following four categories:

1、 Main structural material: high corrosion resistant steel

Low alloy high-strength steel (such as Q345B+N galvanized layer)

Characteristics: Tensile strength ≥ 470MPa, elongation ≥ 21%, surface galvanized layer (thickness ≥ 80 μ m) can isolate direct contact with emulsion.

Application: For load-bearing structures such as main beams and support legs, the corrosion resistance of the galvanized layer is verified through salt spray testing (no red rust for ≥ 1000 hours).

Stainless steel (such as 316L)

Characteristics: Contains 16-18% chromium, 2-3% molybdenum, with a corrosion resistance equivalent (PREN) of ≥ 30, suitable for emulsion splash zones.

Application: Hydraulic cylinder piston rod, pin shaft and other easily corroded components, with a cost 40-60% higher than ordinary steel.

2、 Hydraulic system material: emulsion resistant alloy

Hydraulic pipeline (304/316L stainless steel)

Characteristics: 304 stainless steel is resistant to emulsion pH 6-8 environment, while 316L is resistant to chloride ion corrosion due to molybdenum content (applicable when the chloride ion content of emulsion is ≤ 200mg/L).

Application: High pressure oil pipes and fittings must pass a 1.5 times rated pressure pulse test (≥ 1 million times without leakage).

Hydraulic cylinder body (45 # steel+nickel phosphorus plating layer)

Characteristics: Nickel phosphorus layer thickness ≥ 20 μ m, hardness ≥ 600HV, resistant to emulsion erosion and wear.

Application: Hydraulic cylinder for lifting mechanism, coating adhesion needs to reach level 0 (checked by grid method).

3、 Sealing and protective material: Anti emulsion aging rubber

Fluororubber (FKM)

Characteristics: Resistant to emulsion temperature range of -20 ℃ to+150 ℃, with a volume change rate of ≤ 10% (ASTM D471 standard).

Application: O-ring, hydraulic cylinder seal, with a lifespan three times longer than nitrile rubber (NBR).

Polytetrafluoroethylene (PTFE)

Characteristics: Friction coefficient ≤ 0.05, resistant to emulsion chemical erosion, suitable for sliding bearing bushings.

Application: Rotary bearing seal, pulley shaft sleeve, requiring cold and hot cycling test from -40 ℃ to+200 ℃.

4、 Coating and surface treatment materials: multi-layer protective system

Primer (epoxy zinc rich primer)

Characteristics: Zinc powder content ≥ 80%, dry film thickness ≥ 80 μ m, salt spray resistance ≥ 2000 hours.

Application: Surface pretreatment of steel structures, adhesion to intermediate paint ≥ 5MPa (pull-out test).

Intermediate paint (epoxy mica iron intermediate paint)

Characteristics: Dry film thickness ≥ 120 μ m, impermeability ≤ 0.5g/(m ² · 24h) (water vapor permeability).

Application: Enhance the coating's resistance to cathodic delamination and use it in conjunction with topcoats.

Topcoat (polyurethane topcoat)

Characteristics: Resistant to emulsion splashing, gloss retention rate ≥ 80% (5 years), weather resistance ≥ 10 years.

Application: The final protective layer requires a 480 hour manual accelerated aging test (QUV testing machine).

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