C93700 copper tube production process

The production process of C93700 copper tube combines the traditional copper alloy processing process with special process optimization for its high lead and high tin content. The specific process is as follows:

1. Raw material preparation and smelting

Raw material selection: Electrolytic copper (purity ≥99.9%) is used as the base material, and tin (9%-11%), lead (7.5%-9.5%) and trace antimony, silicon, manganese and other elements are added in proportion to ensure that the alloy composition meets the ASTM B584 standard.

Smelting control: The raw materials are heated to about 1200℃ in an industrial frequency furnace, and electromagnetic stirring is used to ensure uniform distribution of alloy elements, and the smelting time is strictly controlled to reduce oxidation.

2. Casting and molding

Horizontal continuous casting: The molten metal is formed into a tube billet by a horizontal continuous casting machine, and a water cooling system (cooled to 50℃) is used for rapid solidification to refine the grain structure to improve subsequent processing performance.

Centrifugal casting (optional): For high-precision bearing components, a centrifugal casting process is used to use centrifugal force to form uniform tube wall thickness and dense structure.

3. Hot working and cold working

Planetary rolling: The tube billet is rolled using a three-roll or four-roll planetary rolling mill, and the outer diameter and wall thickness are significantly reduced. At the same time, the internal stress is reduced by controlling the rolling temperature (750-850℃).

Joint drawing and coil drawing: The rolled tube is drawn into a surface-hardened stretched tube through a triple-joint drawing device, and then enters the coil drawing machine for high-speed stretching, and finally forms a smooth copper tube of different specifications.

4. Heat treatment and surface treatment

Online annealing: Annealing treatment (temperature of about 600-700℃) is carried out in a protective atmosphere (such as nitrogen) to eliminate work hardening and restore material ductility.

Surface finishing: The oxide scale is removed by pickling, and mechanical polishing or plating (such as nickel plating, chrome plating) enhances corrosion resistance and surface finish. 5. Inspection and packaging

Non-destructive testing: Ultrasonic flaw detection and eddy current testing are used to ensure that the pipe has no internal defects.

Performance testing: Comprehensive testing of indicators such as tensile strength (≥220 MPa), hardness (HB 55-75), and elongation (≥15%).

Product advantages of C93700 copper tube

1. Excellent mechanical properties

High strength and toughness: Tensile strength reaches 220-400 MPa, yield strength is 138-220 MPa, with high hardness (Brinell hardness 60-150 HB) and 25% elongation, suitable for high-load friction environment.

Fatigue resistance: Fatigue strength can reach 90 MPa under 10^8 cycles, which is better than most bronze alloys.

2. Unique physical properties

Self-lubricity: High lead content (7.5%-9.5%) forms a uniform lubricating film during friction, reducing wear, and is particularly suitable for bearings and bushings in oil-free or low-oil conditions.

Thermal conductivity and electrical conductivity: The thermal conductivity is about 12% IACS, and the electrical conductivity is moderate, which is suitable for electrical components that require heat dissipation and current conduction.

3. Excellent corrosion resistance

Environmental adaptability: It is stable in fresh water, sea water and weakly acidic environments (such as mineral water and paper mill sulfite solution), and the annual corrosion rate is less than 1/25 of carbon steel.

Surface treatment compatibility: It supports a variety of anti-corrosion treatments such as plating and coating to further extend the service life.

4. Processing economy

Easy cutting and forming: Lead particles improve chip breaking performance, and the cutting efficiency is 20%-30% higher than that of ordinary bronze; it supports a variety of forming processes such as casting, rolling, and extrusion, and the yield rate is as high as 68% or more.

Cost advantage: Compared with nickel bronze or aluminum bronze, the material cost is reduced by about 15%-20%, which is suitable for mass production.

5. Wide range of application fields

Machinery manufacturing: used for heavy-duty components such as high-speed bearings, gears, pump impellers, etc.

Automobile and aviation: key components such as engine bushings and auxiliary connecting rods, which can withstand high temperature and high pressure.

Marine engineering: propellers, sliders and other seawater corrosion-resistant components.

Electrical engineering: contactors, wiring terminals and other conductive wear-resistant components.