Nickel-based alloy tubes are tubular materials with nickel as the matrix (content ≥50%) and alloy elements such as chromium, molybdenum, and niobium added. With excellent corrosion resistance, high-temperature strength and comprehensive performance, they are widely used in high-end industrial fields. The following is a detailed description of composition, performance, specifications and applications:

Composition and type

- Core system: Based on nickel (Ni), it is divided into different series according to the difference in alloy elements:

- Nickel-chromium (Ni-Cr) system: such as Inconel 600 (Ni-16Cr-8Fe), resistant to oxidation and high-temperature corrosion.

- Nickel-chromium-molybdenum (Ni-Cr-Mo) system: such as Hastelloy C-276 (Ni-16Cr-16Mo-5Fe), resistant to strong reducing acid and chloride ion corrosion.

- Nickel-iron-chromium (Ni-Fe-Cr) system: such as Incoloy 825 (Ni-42Fe-21Cr-3Mo), resistant to sulfuric acid, phosphoric acid and seawater corrosion.

- Precipitation hardening type: such as Inconel 718 (Ni-52Cr-19Fe-5Mo), which improves high-temperature strength through aging strengthening.

- Typical performance differences of grades:

- Corrosion resistance: Hastelloy C-276 resists wet chlorine, hypochlorite and strong oxidants; Incoloy 825 resists sulfuric acid, hydrochloric acid and stress corrosion.

- High temperature strength: Inconel 625 (Ni-21Cr-9Mo) still maintains high tensile strength above 650℃.

Performance characteristics

- Corrosion resistance:

- Resistance to various media: Excellent performance in seawater, chloride ions, hydrofluoric acid, sulfuric acid, nitric acid and high-temperature and high-pressure corrosive media, especially suitable for scenes where stainless steel fails (such as hydrometallurgy, chemical pickling).

- Surface passivation: Chromium and molybdenum elements form a dense oxide film to prevent intergranular corrosion and pitting.

- High temperature performance:

- Heat resistance: Most grades can be used for a long time at 600℃~1200℃, and the tensile strength of Inconel 718 is still over 1000MPa at 700℃.

- Oxidation resistance: When the chromium content is ≥15%, it can resist carburization and sulfide corrosion in high-temperature flue gas.

- Mechanical and processability:

- Strength: Hastelloy C-276 has a room temperature tensile strength of ≥730MPa, and Inconel 625 can reach 890MPa, which is better than ordinary stainless steel.

- Formability: It can be processed by cold drawing and hot extrusion. The heat input needs to be controlled during welding (TIG welding is recommended), and degreasing is required before welding to prevent thermal cracking.

Specifications and shapes

- Pipe diameter:

- Seamless pipe: outer diameter 6mm~610mm, wall thickness 1mm~50mm;

- Welded pipe: outer diameter 10mm~2000mm, wall thickness 0.5mm~25mm, support large diameter customization.

- Length: conventional 6m~12m, can be cut to size, coil length can reach hundreds of meters (small diameter).

- Surface treatment:

- Industrial grade (pickling/sandblasting), bright grade (polishing), special anti-corrosion coating (such as passivation treatment).

- Implementation standards:

- American standard: ASTM B163 (seamless pipe), ASTM B622 (welded pipe);

- National standard: GB/T 15007, GB/T 15008.

Application areas

- Oil and gas:

- Deep-sea oil well pipes, gathering and transportation pipelines (resistant to H₂S, CO₂ and high salt corrosion);

- Heat exchange tubes and reactor linings for refining equipment, resistant to high-temperature sulfur media.

- Chemical and pharmaceutical:

- Concentrated hydrochloric acid/sulfuric acid transmission pipelines, catalyst regenerator pipes, replacing carbon steel or stainless steel;

- Corrosion-resistant pipelines for pharmaceutical equipment (compliant with FDA certification grades), resistant to acid, alkali and solvent corrosion.

- Energy and environmental protection:

- Nuclear power plant steam generator heat transfer tubes (Inconel 690), resistant to high temperature, high pressure and radiation;

- Waste incinerator superheater tubes, resistant to high-temperature chloride corrosion.

- Marine engineering:

- Pipes for seawater desalination equipment (Incoloy 825), resistant to chloride ion stress corrosion;

- Subsea pipelines, offshore platform cooling systems, resistant to seawater scouring and microbial corrosion.

Product Advantages

Nickel-based alloy pipes, with their characteristics of "extreme corrosion resistance + high temperature strength + fatigue resistance", solve the failure problem of stainless steel in harsh environments, especially in H₂S, Cl⁻, and high-temperature oxidizing media. Customized specifications (such as thin walls and large diameters) can meet the needs of special working conditions such as high pressure and deep cold, and are the core corrosion-resistant pipes in the high-end industrial field.