HOT LINE: +86-510-80628100
2019-05-15 MetalForm China 2019 (Shanghai Show) 2017-07-11 BICES 2017 No. 14 China construction machinery exhibition

Technical Article

Hydraulic Cylinder

Current Location: HOME > Technical Article

Piston rod surface treatment

1. Quenching and tempering treatment

The purpose of quenching and tempering treatment is to make the piston rod have comprehensive mechanical properties with good matching of strength, hardness, plasticity and toughness, which is ready for subsequent surface quenching.

2. Surface hardening

The piston rod moves frequently during the working process. Therefore, in addition to having good comprehensive mechanical properties to prevent deformation and fracture, the surface is also required to have high wear resistance. The surface hardness is required to reach 58-62HRC.In the production process, high-frequency quenching is often used.

3. stress relief annealing

Because surface quenching uses the product's own waste heat for tempering treatment, the tempering temperature is gradually reduced, there is no complete tempering heat preservation process. The tempering time is short, the stress relief is incomplete, and there are large residual stresses in some products. Therefore, the piston rod must be annealed before chrome plating to eliminate internal stress caused by grinding and surface treatment.

4. Electroless nickel-phosphorus plating on the surface

In addition to hard chromium plating on the surface of the piston rod for hydraulic cylinders, the outer surface of the piston rod can also be electrolessly plated with nickel and phosphorus;

The surface of the piston rod with special requirements can also be thermal sprayed alloy or sprayed ceramic layer.



Performance comparison of various coatings on piston rods

Type of coating

Coating hardness HV

Wear resistance state

Salt spray test (hours)

Material utilization

Equipment complexity

Single layer chromium

700-1000

Wearable

48-96

20-30

generally

Milky white chromium + chromium

700-1000

Wearable

96

18-25

More equipment

Three layers of chromium

700-1000

Wearable

96-192

18-25

More equipment

Single layer nickel + chromium

700-1000

Abrasion resistance, good binding force

96-128

25-35

More equipment

Double nickel + chromium

700-1000

Abrasion resistance, good binding force

96-192

20-30

Complex process

Electroless Nickel

500-700

More wear-resistant

48-96

40-60

Simple equipment

Electroless nickel + chromium

700-1000

Wearable

96-192

30-50

generally

Tungsten alloy Coating

500-650

Wearable

48

65

Complex equipment

Nickel-iron-cobalt coating

550-700

Wearable

96

70

generally

Nickel-cobalt-iron Coating (Nano)

650-750

Super wear-resistant

Greater than 192

85

generally

Cobalt Phosphorus Coating

550-700

Wearable

Greater than 192

80

generally

Thermal spray ceramics

1000-1300

Wearable

Greater than 192

90

Complex equipment

Nano chromium coating

900-1300

Super wear-resistant

Greater than 500

30-50

Pulse power

Dw-032 high efficiency chrome plating

900-1300

Super wear-resistant

Greater than 750

70

Ordinary equipment

Structured chrome plating

800-1000

Wearable

Greater than 300

25-40

Complex equipment

return
| TIME: 2021.08.31    VIEW: