SIST EN 3354:2014

Overview

EN 3354:2013 is a European aerospace material standard that specifies requirements for titanium alloy Ti‑6Al‑4V in the annealed condition, supplied as sheet for superplastic forming with thickness a ≤ 6 mm. Prepared under CEN/ASD‑STAN, this standard sets delivery, mechanical and microstructural expectations to ensure safe, repeatable use in aerospace applications.

Key highlights include the material designation, delivery condition, heat treatment, mechanical property limits and surface condition criteria relevant to superplastic forming and downstream aerospace manufacturing.

Key Topics

• Material: Titanium alloy Ti‑6Al‑4V (Aerospace series)
• Form: Rolled sheet for superplastic forming, thickness a ≤ 6 mm
• Delivery condition: Annealed; heat treatment specified as 690 °C ≤ θ ≤ 840 °C, t ≥ 30 min, followed by air cooling (AC) or cooling in an inert atmosphere
• Mechanical properties:
  • Proof stress Rp0,2 ≥ 870 MPa
  • Tensile strength Rm between 925 and 1 180 MPa
  • Minimum elongation A (%) varies by thickness:
    • a ≤ 0,6 mm: A ≥ 6 %
    • 0,6 < a ≤ 1,6 mm: A ≥ 8 %
    • 1,6 < a ≤ 6 mm: A ≥ 10 %
• Microstructure: Two‑phase (α + β) with primary α ≥ 40 %; grain size requirements referenced
• Surface quality: Surface roughness and contamination limits apply; typical Ra ≤ 0,6 µm unless otherwise agreed
• Testing & inspection: References and test methods (microstructure, grain size, surface texture) are normatively cited and apply for qualification, marking and dimensional inspection

Applications

EN 3354:2013 is intended for aerospace manufacturers and suppliers specifying Ti‑6Al‑4V sheet for components formed by superplastic processes. Typical practical values of the standard include:

• Ensuring consistent mechanical strength and ductility suitable for superplastic forming operations
• Defining heat treatment and microstructure control to achieve predictable forming behavior
• Establishing surface finish and inspection criteria to reduce scrap and improve assembly compatibility
• Providing a framework for purchaser–manufacturer agreements on forming capability, product qualification and acceptance criteria

This standard supports use in structural and formed aerospace parts where high strength, low density and superplastic formability are required.

Related Standards

Normative references included in EN 3354:2013 (select examples):

• EN 4800‑001 - Titanium and titanium alloys - Technical specification (plate, sheet, strip)
• EN 2338 - Sheets, hot rolled in titanium and titanium alloys (0,8 mm ≤ a ≤ 6 mm)
• EN 3114‑004 - Microstructure of (α + β) titanium alloy wrought products (sheet for superplastic forming)
• EN 2002‑8 - Test methods: micrographic grain size determination
• EN 4258, EN 4500‑004 and ISO 4288 - Organizational, drafting and surface texture rules

For procurement, inspection and qualification, purchasers and suppliers should reference EN 3354:2013 alongside these related documents and agree any capability clauses or specific qualification programs prior to production.