UIC Leaflet 897-23: Quality Requirements for Welding Railway Steel Structures

What is UIC Leaflet 897-23?

UIC Leaflet 897-23 is a specialized technical standard titled “Technical specification for the welding of steel structures for railway vehicles.” In the manufacturing of Rolling Stock, welding is considered a “special process,” meaning the quality of the weld cannot be fully verified by inspection alone after it is finished—the process itself must be strictly controlled.

This leaflet provides the framework for Quality Assurance in welding operations, covering everything from the selection of filler materials to the qualification of the welders. It ensures that the Structural Integrity of the vehicle’s chassis, bogies, and body shells can withstand the intense cyclic loading and vibrations of rail operations.

Technical Requirements for Welding Operations

UIC 897-23 establishes rigorous Technical Delivery Conditions for manufacturers. The standard focuses on several key areas to prevent weld failure:

• Welding Personnel Qualification: Requirement for welders and welding coordinators to hold valid certifications according to international standards (e.g., ISO 9606).
• Base Materials and Filler Metals: Standards for matching the welding wire or electrodes to the specific grade of steel used in the vehicle structure.
• WPS (Welding Procedure Specifications): Mandatory use of written instructions that define parameters such as voltage, current, travel speed, and pre-heat temperatures.
• Weld Performance Classes: Classification of welds based on their safety significance (e.g., high-stress bogie welds vs. low-stress interior brackets).

Testing and Acceptance Criteria

To ensure that the Welding meets safety standards, UIC 897-23 mandates a combination of destructive and non-destructive testing:

• Visual Inspection: Checking for surface defects like undercut, porosity, or misalignment.
• Non-Destructive Testing (NDT): Use of Radiographic (X-ray), Ultrasonic, or Magnetic Particle testing to find internal flaws in critical joints.
• Macrographic Examination: Cutting samples of test welds to examine the internal grain structure and penetration depth.

Relationship with EN 15085

In the modern European railway industry, the principles established in UIC 897-23 have been largely formalized and expanded into the EN 15085 series (Railway applications – Welding of railway vehicles and components). While UIC 897-23 remains a reference for global interoperability, EN 15085 is now the mandatory Certification standard for manufacturers supplying the European market.

Comparison: Weld Performance Categories (CP)