I. Core Content and Scope of ASTM B363 Titanium Alloy Butt-Welding Fittings The ASTM B363 standard comprehensively governs titanium and titanium alloy butt-welding fittings, primarily for corrosion-resistant and high-temperature service. Key specifications include: Material Sources and Processing Requirements Raw materials must comply with ASTM standards: plates (B265), bars/billets (B348), forgings (B381), seamless pipes (B861),