QUALIFICATION PROCESS FOR MICRO PLASMA WELDING OF TUBE-TO-TUBULAR PLATE JOINTS IN LOW-CARBON AUSTENITIC STEEL

Micro plasma welding is a specialized arc welding process that demands high precision and control, making it particularly suitable for thin-walled components and small-scale assemblies. In accordance with international and national standards, welding is classified as a special process, requiring stringent measures to ensure consistent and repeatable outcomes. Given the critical nature of micro plasma welding—especially in applications where dimensional accuracy and metallurgical integrity are paramount—both the welding technology and the personnel performing the welding must be properly qualified. The qualification of a micro plasma welding process entails rigorous assessment and documentation, considering factors such as joint configuration, welding parameters, base material type, and the specific characteristics of the welded connection. This paper presents the key quality requirements and procedural steps necessary for the qualification of a micro plasma welding process applied to a tube-to-tubular plate joint, using a low-carbon austenitic stainless steel as the base material.