C61900 copper tube production process

The C61900 copper tube production process combines traditional copper tube manufacturing technology with the specific processing requirements of aluminum bronze alloys. Its process mainly includes the following key links:

1. Raw material preparation and alloy smelting

Raw material selection: electrolytic copper is used as the core substrate (accounting for 83.6-88.5%), and aluminum (8.5-10%), iron (3-4.5%), zinc (≤0.8%) and other elements are accurately proportioned. The content of impurities such as lead and tin (all ≤0.6%) is strictly controlled to meet ASTM B150/B150M standards.

Smelting process: Induction furnace or electric arc furnace is used to heat copper to 1100-1200℃ for melting, and alloy elements such as aluminum and iron are added simultaneously. Oxidation is reduced by inert gas protection (such as argon), and ZrO₂ ceramic filtration technology is used to improve the purity of the melt and ensure uniform alloy composition.

2. Casting and forming

Horizontal continuous casting: The molten alloy is formed into a tube billet through a horizontal continuous casting machine, and the cooling rate is controlled to refine the grain structure and reduce shrinkage and segregation.

Hot rolling and planetary rolling: The tube billet is initially formed by multiple hot rolling (temperature 800-900℃), and then the planetary rolling mill is used for efficient diameter reduction to achieve wall thickness uniformity (tolerance ±0.02mm). The rolling pressure and temperature need to be precisely controlled at this stage to avoid surface cracks.

3. Cold working and finishing

Drawing process: The tube diameter is further reduced by cold drawing, and the friction coefficient is reduced by emulsion lubrication. Combined with intermediate annealing (650-750℃), work hardening is eliminated and ductility is improved.

Internal thread processing: The internal thread structure is formed by spinning or rolling technology to enhance the heat exchange efficiency, which is suitable for scenarios such as nuclear power steam generator heat transfer tubes.

4. Heat treatment and surface treatment

Continuous annealing: Recrystallization annealing is carried out in a protective atmosphere (such as nitrogen) to eliminate residual stress and optimize mechanical properties (such as yield strength ≥ 275MPa).

Pickling and polishing: Use a mixture of nitric acid and hydrofluoric acid to remove oxide scale, and electrolytic polishing to improve surface finish (Ra ≤ 0.8μm) to meet the requirements of high-precision components.

5. Quality testing and certification

Laboratory testing: covers chemical composition analysis (spectrometer), mechanical property testing (tensile testing machine), metallographic structure observation (electron microscope) and corrosion resistance evaluation (salt spray test).

Certification system: Passed ISO 9001, ASTM B150 and nuclear industry ASME certification to ensure that the product meets drinking water (NSF/ANSI 61) and nuclear power safety standards.

Product advantages of C61900 copper tube

1. Excellent mechanical properties

High strength and wear resistance: tensile strength ≥585MPa, yield strength ≥275MPa, hardness up to 170HB, hard phase formed by aluminum element (such as κ-Al₂Cu) significantly improves wear resistance, suitable for high-load parts such as gears and bearings.

Excellent ductility: elongation ≥20%, can withstand complex cold forming processing (such as deep drawing, bending).

2. Outstanding corrosion resistance

Adaptability to marine environment: annual corrosion rate <0.02mm in 3.5% NaCl solution, Fe-Al synergistic passivation film effectively resists chloride ion corrosion, and the service life is more than 30% higher than 316L stainless steel.

Resistant to chemical media: stable to non-oxidizing acids (such as dilute sulfuric acid) and organic solvents, suitable for refinery pipelines and chemical reactor linings.

3. Thermal management and electrical conductivity

Thermal conductivity 58.6 W/m·K: better than brass (109 W/m·K) but maintains the efficient heat dissipation capacity of the copper matrix, suitable for motor windings and radiators.

Conductivity 30% IACS: meets the electrical conductivity requirements of electrical switches and contactors, while also having high strength.

4. Process compatibility and environmental protection

Welding performance: supports TIG welding and laser welding, weld strength coefficient ≥0.9, no tendency to thermal cracking.

100% recyclable: smelting and regeneration energy consumption is only 15% of the original copper, in line with the RoHS directive and green manufacturing trends.

5. Wide range of applications

Aerospace: used for gas turbine engine combustion chamber liners, resistant to 800℃ high temperature gas.

Nuclear power and energy: as a heat transfer tube for pressurized water reactor steam generators, secondary pollution is avoided through a turning process without turning fluid.

Ship and marine engineering: the life of the pipeline system of the seawater desalination device can reach 20 years, and the maintenance cost is reduced by 40%.