The basic requirements for welding repair of cast steel components in railway vehicles include general requirements, enterprise requirements, personnel requirements, environmental requirements, and process requirements.
1. General requirements
The welding repair scope of casting defects should comply with the technical conditions, maintenance regulations or drawing regulations of railway 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 the welding and repair production of cast steel components for railway vehicles must have at least EN 15085-2 CL2 and above qualifications including “P”. Enterprises engaged in the procurement, assembly, and sales of cast steel welding and repair components for railway vehicles must have EN 15085-2 CL2 and above qualifications including “S”.
3. Personnel Requirements
Production personnel engaged in welding repair of cast steel components for railway vehicles should be familiar with the welding performance of cast steel materials and must obtain an ISO 9606-1:2012 international welder qualification certificate.
4. Environmental requirements
Welding repair parts should avoid artificial blowing and ventilation, with a temperature of no less than 5 ℃ and a humidity of no more than 80%. When the temperature of welded steel castings is below 5 ℃, welding repair is not allowed, but local preheating is allowed for welding repair.
5. Process requirements
The welding repair of cast steel components should be carried out in accordance with the requirements of ISO 15607:2019 “Welding Procedure Specification and Evaluation of Metallic Materials”. The welding repair process must undergo welding process qualification to verify its compliance, and the welding process qualification shall refer to ISO 15614 and ISO 11970 standards.
The welding power supply should comply with the provisions of GB/T 15579.1-2013; Welding equipment and auxiliary equipment should be regularly maintained and maintained to ensure their good condition, safety, and reliability.
Mixed gas shielded arc welding can be used for welding repair of cast steel parts. The safety of welding repair and cutting operations should comply with the provisions of GB/T 9448-1999 “Welding and Cutting Safety”.
Complete welding repair records need to be established for key cast steel components for future reference.