What Affects The Manufacturing Process Of Titanium Tubes?

The multiple factors influenced the the manufacturing process of titanium tubes,including material properties, technical parameters, and equipment conditions. It directly determines the product's dimensional accuracy, mechanical properties, corrosion resistance, and application adaptability.

 

 

1.Raw Material Properties

• Raw material properties determines processing difficulty (e.g., Gr5 requires higher rolling force because of high strength), heat treatment system (e.g., solution temperature), and welding compatibility.
• Chemical Composition Purity,Insufficient purity causes decreased plasticity and increased risk of welding cracks; strict control of smelting processes (e.g., Vacuum Arc Remelting, VAR) is required

Ingot/Billet Quality defects are inherited by finished tubes; forging and extrusion are needed to refine grains and eliminate defects

 

2.Forming Process Parameters

• In hot Extrusion, too low temperature causes high deformation resistance and tube cracking; too high temperature result in coarse grains, affecting mechanical properties.The key Parameters are extrusion temperature (800-1000℃), extrusion speed, die design.
• Cold Rolling/Cold ：Excessive deformation trends to severe work hardening, requiring intermediate annealing; poor lubrication easily causes surface scratches and die sticking.Key Parameters includes deformation amount (single pass ≤30%), lubrication conditions, roll/die accuracy.
• Welding (Except Seamless Tubes): Improper protection causes weld oxidation and embrittlement; excessive current easily leads to defects,for example burn-through and incomplete penetration. The key Parameters are welding method (TIG, laser welding), shielding gas (Ar) purity, welding current.

 

3.Heat Treatment

• Annealing:Eliminates work hardening, refines grains, and improves plasticity and toughness; excessive temperature leads to coarse grains and reduced strength (temperature (550-750℃), holding time, cooling rate)

 

• Solution Aging ( Gr5): Enhances alloy strength and hardness; improper parameters result in unstable performance in Solution temperature (920-960℃) and aging temperature (450-550℃)

 

4. Surface Treatment and Quality Control

Link	Key Factors	Impact
Surface Cleaning	Pickling formula (HF+HNO₃ mixed acid), pickling time	Removes oxide scale and oil; over-pickling causes surface corrosion pits and corrosion resistance
Dimensional Accuracy Control	Die/roll accuracy, online testing equipment (e.g., ultrasonic thickness measurement)	affect tube outer diameter and wall thickness tolerance (e.g., ASTM B337 standard requires wall thickness tolerance of ±5%)
Defect Detection	NDT methods (UT, ET, X-ray)	Identifies internal cracks, uneven wall thickness, inclusions and other defects to prevent unqualified products.

 

5. Equipment and Environmental Conditions

Category	Key Factors	Impact
Equipment Accuracy	Coaxiality and pressure control accuracy of extruders and rolling mills	Insufficient equipment accuracy leads to excessive tube ovality and uneven wall thickness
Environmental Control	Workshop humidity (≤65%), dust content	Humid environments easily cause surface oxidation of titanium materials; dust causes surface scratches, affecting product appearance and corrosion resistance

 

 

• Forming and Dimensional Accuracy

Hot extrusion + cold rolling: High precision (outer diameter tolerance ±0.1mm) for aerospace high-precision titanium tubes.

Single hot extrusion: High efficiency, larger tolerance (±0.5mm) for industrial pipelines.

 

• Heat Treatment and Mechanical Properties

Gr2: Annealed at 550℃ → Tensile strength ≥345MPa, elongation ≥20% ( like chemical pipelines).

Gr5: Solution-treated at 940℃ + aged at 500℃ → Tensile strength ≥900MPa, elongation ≥10% (like aviation hydraulic tubes).

 

• Surface Treatment and Corrosion Resistance

Pickling + passivation: Forms dense TiO₂ oxide film → Enhances chlorine/seawater corrosion resistance (harsh environments).

 

 

1.High-Precision Needs in Aerospace and Medical:

vacuum smelted ingot → hot extrusion → multi-pass cold rolling → precision annealing → online non-destructive testing

Control the cold rolling deformation amount to ≤25% and the intermediate annealing temperature to 600℃ to ensure the grain size is ≤50μm.

 

2.Corrosion Resistance Needs in Chemical Industry and Marine:

Gr2 and Gr7 grades, optimize the pickling process (HF:HNO₃=1:3, pickling time 3-5 minutes).

Use high-purity argon protection (purity ≥99.99%) to avoid weld oxidation.

 

3.High-Strength Needs in Mechanical and Aviation Structures:

Select Gr5 alloy, "hot extrusion → solution aging treatment → cold drawing finishing.

Set the solution temperature to 940℃ (holding for 1 hour) and the aging temperature to 500℃ (holding for 4 hours) to improve strength,ensuring toughness.