The production process and product advantages of C71500 copper tube:

I. Production process

Basic process flow

The production of C71500 copper tube follows the ASTM B333 standard, and the core processes include:

Smelting and continuous casting: Copper, nickel and other raw materials are mixed in proportion and smelted into molten steel, and the billet is formed by horizontal continuous casting.

Rolling and cold working: The billet is formed by planetary rolling, triple drawing, and coil drawing. Cold working (such as drawing and extrusion) can improve dimensional accuracy and surface quality, and is suitable for precision parts such as thin-walled tubes and filaments.

Annealing treatment: The annealing temperature range is 900–1100°C, and the time is 2.5 hours to eliminate stress and improve plasticity.

Application of advanced technology

Introducing CNC machine tools, automated production lines and 3D printing technology to improve processing efficiency and complex parts manufacturing capabilities.

Welding uses GTAW (argon arc welding) with welding wire containing deoxidizing elements (Ti, Mn), strictly controls pre-welding cleaning to ensure that the weld is free of cracks and pores, and the first-time pass rate is more than 98%.

Quality Control

Grain size, internal defects (such as pores, inclusions) and surface quality are strictly tested.

After annealing, it is necessary to pass the resistivity test (allowable deviation ±5%) and winding test to ensure no breakage.

2. Product advantages

Excellent corrosion resistance

In seawater environment, it can withstand flow rates of 2.2-4 m/s, resist pitting and stress corrosion cracking, and is suitable for corrosive environments such as power stations, seawater desalination, and ships.

The synergistic effect of nickel (29-33%) and iron (0.4-1.0%) in the alloy enhances corrosion resistance, especially under high temperature and high salt conditions.

Excellent mechanical properties

Strength and plasticity: Soft state (M) tensile strength 370 MPa, elongation 35%; semi-hard state (Y2) tensile strength up to 480 MPa. After cold working, the strength is further improved while maintaining low temperature toughness (no embrittlement).

High temperature performance: The design temperature of the annealed state can reach 371°C, and the cold-rolled seamless pipe can reach 416°C.

Good processing and welding performance

The single α phase structure makes its thermal conductivity close to that of carbon steel, welding does not require preheating or post-treatment, and the deformation of the heat-affected zone is controllable.

Supports cold/hot processing, with outstanding cold processing capabilities, but not suitable for hot forming.

Wide application areas

Marine engineering: seawater pipelines, condensers, heat exchangers.

Energy and chemical industry: nuclear power plant cooling systems, petrochemical equipment, high-pressure valves.

Others: cryogenic equipment, medical equipment and decoration fields.