Material system and type

- Core alloy category:

- Corrosion-resistant alloy tubes: such as Hastelloy C-276 and Monel 400, containing nickel, chromium, molybdenum and other elements, resistant to seawater, strong acid and chloride ion corrosion;

- High-temperature alloy tubes: such as Inconel 625 and Incoloy 800H, nickel-based or iron-nickel-based alloys, can be used for a long time at 600℃~1200℃;

- Precision functional alloy tubes:

- Soft magnetic alloys (such as 1J50, 1J79): low coercivity, used for transformers and sensors;

- Expansion alloys (such as 4J36, 4J42): low thermal expansion coefficient, matching ceramic/glass packaging;

- Elastic alloys (such as 3J53): high elastic limit, used for precision springs and diaphragms.

- Typical grade characteristics:

- Inconel 718 alloy tube: precipitation hardening type, tensile strength exceeds 1000MPa at 700℃, creep resistance;

- 1J79 Permalloy tube: magnetic permeability ≥100,000, used for high-frequency electromagnetic components.

Performance characteristics

- Dimension and surface accuracy:

- Outer diameter tolerance: ±0.05mm~±0.1mm (ordinary precision grade), ±0.01mm~±0.03mm (ultra-high precision grade);

- Wall thickness tolerance: ±5%~±2% (conventional), thin-walled tube (wall thickness ≤0.5mm) can reach ±0.02mm;

- Surface roughness: Ra≤0.8μm in cold-rolled state, Ra≤0.2μm after polishing, meeting mirror requirements.

- Mechanical and environmental adaptability:

- Strength: Hastelloy C-276 tube has a room temperature tensile strength of ≥730MPa, which is better than 316L stainless steel;

- Corrosion resistance: It has significant pitting resistance in acidic media containing Cl⁻ (such as hydrochloric acid and sulfuric acid), and is suitable for chemical and marine engineering;

- High temperature stability: Inconel 600 tube has excellent oxidation resistance at 1093℃ and can be used for furnace tubes and thermocouple protective sleeves.

- Functional characteristics:

- Magnetic properties: Soft magnetic alloy tubes have high magnetic permeability in weak magnetic fields and are suitable for magnetic shielding and mutual inductors;

- Low expansion: The expansion coefficient of 4J36 (Invar alloy) tubes at -200℃~+200℃ is ≤1.5×10⁻⁶/℃, and is used for precision instrument structural parts.

Specifications and manufacturing process

- Outer diameter and wall thickness:

- Conventional range: outer diameter 1mm~200mm, wall thickness 0.1mm~10mm;

- Special specifications: capillary tube (outer diameter ≤3mm, wall thickness ≤0.2mm), large-diameter thin-walled tube (outer diameter ≥100mm, wall thickness ≤2mm).

- Length and shape:

- Straight tube: usually 1m~6m, can be cut to size; coil: length can reach hundreds of meters (small diameter);

- Cross-sectional shape: round tube, elliptical tube, rectangular tube (customized special-shaped tubes require mold opening).

- Manufacturing process:

- Cold rolling/cold drawing: Improve precision through multiple rolling or drawing, suitable for thin-walled tubes (wall thickness ≤1mm);

- Hot extrusion + cold processing: Commonly used for high-temperature alloy tubes, first extrusion forming and then cold rolling to refine the grains;

- Welding and seamless tubes:

- Seamless tubes: High strength, suitable for high-pressure conditions (such as aviation oil pipes);

- Welded pipes: Formed by laser welding or TIG welding, the inner wall weld can be electrolytically polished to eliminate stress.

- Implementation standards:

- American standard: ASTM B163 (nickel alloy tube), ASTM A269 (stainless steel precision tube);

- National standard: GB/T 15019 (alloy tube), GB/T 30066 (precision alloy tube).

Application areas

- Aerospace:

- Engine fuel pipe (Inconel 718), resistant to high pressure (≥30MPa) and high temperature of 650℃;

- Hydraulic system precision conduit (titanium alloy or nickel-based alloy), resistant to vibration fatigue and corrosion.

- Electronics and semiconductors:

- Gas transmission tubes for semiconductor equipment (316L stainless steel or nickel-based alloy), inner wall roughness Ra≤0.1μm, anti-pollution;

- Magnetic shielding tubes (1J79 alloy), used for nuclear magnetic resonance instruments and sensor anti-interference.

- Medical and scientific research:

- Interventional therapy catheters (nickel-titanium alloy), superelasticity + memory performance, can be bent through blood vessels;

- Laboratory corrosion-resistant reaction tubes (Hastelloy alloy), resistant to strong corrosive media such as aqua regia and hydrofluoric acid.

- Energy and precision instruments:

- Nuclear power plant steam generator U-tube (Inconel 690), radiation and high temperature and high pressure (≥15MPa);

- Precision pressure gauge spring tubes (3J53 alloy), stable elasticity, long-term use accuracy deviation ≤0.5%.