The basic requirements for welding repair of rail vehicle steel castings include: general requirements, enterprise requirements, personnel requirements, environmental requirements, and process requirements.
1. General requirements
The welding repair scope of defects in steel castings shall comply with the technical conditions, maintenance procedures, or drawings of rail vehicle products. When there are no clear provisions in the product drawings, technical conditions, and supply and demand contracts, it can be considered that all defects can be repaired by welding.
2. Enterprise Requirements
Enterprises engaged in welding repair production of steel castings for rail vehicles must at least have the qualification of EN 15085-2 CL2 and above, including “P”. Enterprises engaged in welding repair procurement, assembly, and sales of steel castings for rail vehicles must have the qualification of EN 15085-2 CL2 and above, including “S”.
3. Personnel requirements
Production personnel engaged in welding repair of steel castings for railway vehicles should be familiar with the welding performance of cast steel materials, and must obtain ISO 9606-1:2012 International Welder Qualification Certificate.
4. Environmental requirements
Artificial blowing and ventilation shall be avoided at the welding repair site, with the temperature not lower than 5 ℃ and the humidity not higher than 80%. When the temperature of the steel castings repaired by welding is lower than 5 ℃, welding repair is not allowed, but partial preheating is allowed before welding repair.
5. Process requirements
For welding repair of steel castings, a welding procedure specification shall be prepared in accordance with the requirements of ISO 15607:2019 “Welding Procedure Specification and Qualification for Metallic Materials”. The welding repair process must undergo welding procedure qualification to verify its compliance with the standards of ISO 15614 and ISO 11970.
Welding power supply shall comply with the provisions of GB/T 15579.1-2013; Welding equipment and auxiliary appliances should be regularly maintained to ensure that they are in good condition, safe, and reliable.
The repair welding of steel castings can be performed using mixed gas shielded arc welding. The operational safety of welding repair and cutting shall comply with the provisions of GB/T 9448-1999 “Safety in Welding and Cutting”.
Complete welding repair records shall be established for key steel castings for future reference.