TOBO Industrial (Shanghai) Co., Ltd., a leading manufacturer and global supplier of precision-engineered metal products, has announced the expansion of its advanced alloy portfolio with the introduction of Alloy CuNi 90/10 (UNS C70600) Cold-Drawn Seamless Tubes. Engineered for the most demanding marine, offshore, energy, and industrial processing applications, these tubes combine exceptional corrosion resistance with the superior structural integrity of cold-drawn seamless construction.
The Material of Choice for Aggressive Environments
At the heart of this new product line is the UNS C70600 (CuNi 90/10) alloy, a material long trusted in marine and offshore engineering. Comprising approximately 90% copper and 10% nickel with controlled additions of iron and manganese, it delivers a unique combination of properties that make it superior to conventional materials in challenging service conditions.
Unrivaled Seawater Corrosion Resistance: C70600 exhibits extremely low general corrosion rates in seawater, typically below 0.025 mm per year. It provides exceptional protection against pitting, crevice corrosion, and stress-corrosion cracking—common failure modes in chloride-rich environments.
Natural Biofouling Resistance: The alloy's surface chemistry inherently inhibits the adhesion and growth of marine organisms such as barnacles and mussels, reducing maintenance requirements and preserving hydraulic efficiency in seawater systems.
Good Mechanical Properties: With tensile strength ranging from 275-370 MPa in the annealed condition to 480 MPa in hard-drawn tempers, and elongation of 20-40%, C70600 maintains excellent formability and durability across a wide temperature range.
Thermal and Mechanical Stability: The alloy performs reliably from cryogenic conditions up to 371°C, with no low-temperature embrittlement, making it suitable for heat exchangers and condensers.
Proven Longevity: Systems utilizing C70600 components have demonstrated service lives exceeding 30-40 years in marine environments, offering exceptional total cost of ownership despite higher initial material costs.
The Integrity of Cold-Drawn Seamless Construction
A pivotal aspect of this product launch is the cold-drawn seamless manufacturing process. The production begins with hot extrusion of cast billets, followed by cold working (cold drawing) and annealing operations. Cold drawing involves pulling the tube through a die to reduce its diameter and wall thickness while improving dimensional accuracy and surface finish. Intermediate annealing at 650-750°C relieves internal stresses and restores ductility for subsequent processing.
This multi-stage cold-working process results in:
Homogeneous Microstructure: Uniform grain structure around the entire circumference provides consistent mechanical strength and corrosion resistance.
Superior Dimensional Precision: Tolerances as tight as ±0.05mm on wall thickness ensure perfect fit in system assemblies.
Enhanced Fatigue Resistance: Absence of weld defects and associated heat-affected zones results in superior resistance to vibration and pressure cycling, essential for dynamic offshore and power generation environments.
Improved Flow Performance: Smooth internal surface minimizes friction and turbulence, reducing pumping energy requirements.
Quality Assurance and Compliance
TOBO's seamless tubes are manufactured and tested to meet rigorous international standards, including ASTM B111 / ASME SB111 for seamless condenser tubes and ASTM B466 / ASME SB466 for seamless pipe. Each production batch undergoes comprehensive quality verification, including chemical composition analysis (Ni 9.0-11.0%, Fe 1.0-1.8%, Mn ≤1.0%), mechanical testing, eddy current testing per ASTM E243, hydrostatic pressure testing, and flattening and expansion tests per ASTM B153.
Certification options include Mill Test Certificates (MTCs) and EN 10204 Type 3.2 certification through independent third-party inspection by agencies such as SGS, BV, or TUV upon request.
Industry Applications Across Critical Sectors
These high-performance seamless tubes serve essential functions across multiple industries:
Marine and Offshore Engineering: Seawater cooling systems, ballast water management, fire-fighting pipelines, and subsea equipment.
Power Generation: Steam condenser tubing, feedwater heaters, and auxiliary cooling circuits in coastal and nuclear power plants.
Desalination and Water Treatment: Multi-stage flash (MSF) evaporator tube bundles, reverse osmosis (RO) plant piping, and brine heater sections.
Chemical and Petrochemical Processing: Heat exchanger tubes and process piping handling corrosive media.
About TOBO Industrial (Shanghai) Co., Ltd.
TOBO is a professional manufacturer and exporter of precision-engineered metal products based in Shanghai, China. With robust production capacity and a commitment to metallurgical excellence, TOBO serves customers worldwide across marine, energy, chemical, and industrial sectors. The company specializes in copper-nickel alloys, nickel alloys, stainless steels, and associated products for demanding applications, with strict quality control and complete traceability.