Production process of C93700 copper bushing

The production process of C93700 copper bushing covers core links such as casting, machining, heat treatment and surface treatment. The specific process is as follows:

1. Casting process

Material smelting: The raw materials need to be strictly degreased and rust-removed, and heated to 1120-1150℃ in an electric furnace for smelting, and a covering agent (such as charcoal) is added to reduce oxidation. After smelting, the copper liquid needs to be kept at 1050℃ to ensure uniform composition.

Casting method:

Centrifugal casting: The copper liquid is evenly distributed through high-speed rotating molds to eliminate pores and impurities, which is suitable for high-precision bushing production. The pouring temperature is controlled at 1050-1150℃, and special attention should be paid to the segregation control of lead.

Continuous casting: Used to produce bars or tubes to form a dense and non-porous structure and improve the mechanical properties of the material.

Sand casting: Suitable for parts with complex shapes, but attention should be paid to mold design and cooling rate to avoid internal defects.

2. Machining

Rough machining: Use lathes, milling machines and other equipment to remove the blank excess and approach the final size.

Fine machining: Use CNC machine tools for high-precision cutting (turning, drilling, etc.) to ensure dimensional tolerance (±0.02mm) and surface roughness (Ra≤1.6μm). Carbide tools can reduce tool sticking.

3. Heat treatment

Stress relief annealing: Performed at 300-400℃ to eliminate machining residual stress and improve dimensional stability.

4. Surface treatment

Coating technology: Such as nickel plating or chrome plating to enhance corrosion resistance; tin plating is used to improve lubricity.

Mechanical polishing: Improve the surface finish to a mirror effect and reduce the friction coefficient.

Product advantages of C93700 copper bushing

1. Excellent tribological properties

Self-lubricating: Lead content is 7.5-9.5%, a uniform lubricating film is formed during friction, and the friction coefficient is reduced (0.08-0.12), which is suitable for oil-free or insufficient lubrication conditions.

Wear resistance: Tin (8.5-11.5%) forms α-phase and δ-phase eutectic structures with copper matrix, with a hardness of 60 HB and a wear rate more than 30% lower than that of ordinary bronze.

2. Excellent mechanical properties

Tensile strength: 295 MPa, yield strength 138 MPa, elongation 25%, with both high strength and toughness.

Fatigue resistance: Low crack growth rate under cyclic load, suitable for high-frequency vibration environment (such as engine connecting rod bushing).

3. Corrosion resistance

Excellent performance in seawater, acidic mineral water and sulfite environment of paper mill, with a corrosion rate of ≤0.01 mm/year, which is better than most bronze materials.

4. Processing economy

The machinability score is 80 (based on C36000 as 100), and the tool life is extended by 20%, which is suitable for mass production of complex parts.

Can be cast, rolled, extruded, with strong process adaptability.

5. Wide applicability

Industrial fields: heavy-duty bearings (ship propellers, rolling mill roll necks), high-pressure pump and valve components.

Special environments: aerospace components with limited lubrication, corrosion-resistant marine equipment.