GB/T 38526-2020 in English

Core technical requirements of the standard

Key process performance requirements

The pipe needs to pass four core process tests:

• Expansion test: Pipes with outer diameter ≥6mm must meet the expansion rate of 30% without cracks
• Flattening test: Calculate the platen spacing according to the formula H=(1+0.07)t/(0.07+t/D)
• Bending test: 90° bending with a radius of 4 times the outer diameter without cracks
• Hydraulic test: Maintain a pressure of 40MPa for 5 seconds without leakage

Special requirements for material preparation

The standard stipulates that the ingot must undergo:

1. At least two smeltings (the first smelting can use a vacuum consumable arc furnace or a cooling hearth furnace)
2. No alloying elements are allowed to be added in the last smelting
3. Tungsten inert gas welding is prohibited for electrode welding

Quality assurance measures for aerospace applications

Technology evolution background

Compared with traditional titanium tube specifications, this standard has the following:

• New surface contamination layer inspection requirements (GB/T 23603)
• Outer diameter tolerance control accuracy improved by 30%
• Introduce dual melting process restrictions

Implementation suggestions

Manufacturers need to pay special attention to:

1. Establish a melting process traceability system
2. Equip with high-precision eddy current/ultrasonic dual inspection equipment
3. White light illumination inspection is required on the surface after pickling
4. It is recommended to use helium mass spectrometry leak detection instead of traditional water pressure test