7.3.2 ISO 15614 Specification and Qualification of Welding Procedures Explained

Key Concepts of ISO 15614

1. Definition

ISO 15614 is an international standard that specifies the requirements for the qualification of welding procedures for metallic materials. It ensures that welding procedures meet specific quality and performance criteria, thereby guaranteeing the integrity and reliability of welded structures.

2. Scope

The standard covers various aspects of welding procedures, including:

• Material Types: Specifies the types of materials that can be welded, such as carbon steels, stainless steels, and aluminum alloys.
• Welding Processes: Includes manual, semi-automatic, and automatic welding processes like Gas Metal Arc Welding (GMAW), Shielded Metal Arc Welding (SMAW), and Flux-Cored Arc Welding (FCAW).
• Joint Configurations: Defines the types of joints, such as butt, lap, and T-joints, and their specific requirements.

3. Procedure Qualification Record (PQR)

A Procedure Qualification Record (PQR) is a document that records the results of tests performed to qualify a welding procedure. It includes details such as:

• Welding Parameters: Current, voltage, travel speed, and other critical parameters used during the welding process.
• Test Results: Results of mechanical tests, such as tensile, bend, and impact tests, to verify the weld's strength and ductility.
• Non-Destructive Testing (NDT): Results of NDT methods like radiographic or ultrasonic testing to assess the weld's internal quality.

4. Welding Procedure Specification (WPS)

A Welding Procedure Specification (WPS) is a document that provides detailed instructions for performing a specific welding procedure. It includes:

• Preparation Steps: Instructions for preparing materials, setting up equipment, and ensuring proper fit-up of parts to be welded.
• Welding Parameters: Specific parameters to be used during welding, ensuring consistency and quality.
• Post-Welding Steps: Instructions for post-weld heat treatment, cleaning, and inspection.

5. Qualification Testing

Qualification testing involves performing a series of tests to verify that a welding procedure meets the required standards. These tests include:

• Mechanical Testing: Conducting tensile, bend, and impact tests to assess the weld's mechanical properties.
• Visual Inspection: Inspecting the weld visually for defects such as cracks, porosity, and incomplete fusion.
• Non-Destructive Testing (NDT): Using NDT methods to detect internal defects and ensure the weld's integrity.

Examples and Analogies

Imagine ISO 15614 as a blueprint for building a bridge. Just as a blueprint ensures that every part of the bridge is constructed according to plan, ISO 15614 ensures that every weld in a structure meets specific quality standards. The blueprint includes detailed instructions for each step, just as ISO 15614 provides detailed guidelines for welding procedures.

Think of the Procedure Qualification Record (PQR) as a report card for a welding procedure. Just as a report card shows a student's performance in various subjects, the PQR shows the performance of a welding procedure in various tests. It includes grades (test results) that indicate whether the procedure is qualified or needs improvement.

Conclusion

Understanding and implementing ISO 15614 is crucial for ensuring the quality and reliability of welding procedures. By following the detailed guidelines and conducting thorough qualification testing, welders can produce high-quality welds that meet international standards. This ensures the safety, integrity, and performance of welded structures in various industries.