PQR Qualification Requirements for MIL-STD-3040A

PQR Compliance for MIL-STD-3040A (Need To Know Article: 1 of 7)

In military and defense contracting, ensuring the integrity and reliability of welded components is critical and as a result, the standards to qualify your manufacturing and QA processes are stringent. The Procedure Qualification Record (PQR) serves as a critical document in this qualification process, verifying that a specific welding procedure can produce welds meeting the required mechanical properties with no discontinuities or defects.

What Is a PQR?

A PQR is a record of the welding process and variables used during the qualification of a test coupon and the results of the required mechanical tests. It documents the actual parameters and conditions under which the weld was made, providing a basis for developing a Welding Procedure Specification (WPS) that can be used in production.

Key Components of a PQR

A comprehensive PQR should include the following information:

• Base Metals: Identification and chemical composition.

• Welding Processes: Processes used (e.g., GTAW, SMAW).

• Filler Metals: Classification, diameter, and type.

• Welding Parameters: Current, voltage, travel speed, and heat input.

• Joint Design: Type and dimensions.

• Position: Welding position (e.g., 1G, 2G).

• Preheat and Interpass Temperatures: If applicable.

• Post-Weld Heat Treatment (PWHT): Details if performed.

• Mechanical Test Results: Tensile, bend, impact, and hardness tests.

It's essential that the PQR reflects the actual conditions and results of the qualification tests, as this information forms the foundation for the WPS.

PQR testing is specific to material thickness ranges so that multiple PQR test plates may be necessary to qualify for a wider range of base material thicknesses. (See Table X below for specific material thickness ranges). Note that material thickness under 3/8 in. (0.375 in.) will require independent PQR testing from heavier thickness ranges.

Qualification Testing Requirements

To qualify a welding procedure under MIL-STD-3040A, the following tests are typically required:

• Tensile Test: Assesses the strength of the weld.

• Bend Test: Evaluates ductility and soundness.

• Impact Test: Determines toughness, especially at low temperatures.

• Hardness Test: Checks for hardness variations.

Mechanical testing requirements will vary depending on the Weld Classification defined in MIL-STD-3040A. These Weld Classifications (Class I – IV) are determined by design requirements and the service requirements of the welded component. Those different use-cases dictate the type of mechanical tests required for the PQR sample. (See Table VI below)

Welder Qualification

In addition to qualifying the welding procedure, individual welders must also be qualified to ensure they can produce welds that meet the required standards. This involves performing a Welder Performance Qualification (WPQ), which includes:

• Welding a Test Coupon: Under specified conditions.

• Testing the Weld: Subjecting the weld to mechanical tests similar to those in the PQR.

• Documenting Results: Recording the results to ensure compliance with the specified standards.

Reasons That A Welder May Need To Requalify

Welding operators may need to requalify to meet MIL-STD-3040A if one of the following reasons applies to them.

·       The welder has not used the qualified welding process within the past 6 months.

·       The welding position for which the operator is qualified may be different in the new PQR.

·       A continuity document has not been maintained to provide traceability of process use.

Best Practices for PQR and WPQ Compliance

• Documentation: Maintain detailed records of all welding procedures and welder qualifications. United Technical Inc. can provide this documentation through our extensive experience in MIL-STD-3040A compliance

• Training: Ensure all personnel are adequately trained and certified. United Technical Inc. can provide welder and inspector training, as well as testing your weld samples to assure specification compliance.

• Regular Audits: Conduct periodic reviews to ensure ongoing compliance. United Technical Inc. can act as an independent source for periodic self-audits.

• Continuous Improvement: Implement feedback mechanisms to improve welding procedures and practices.

 Contact our team at United Technical Inc. to be your industry partner in achieving MIL-STD-3040A compliance as well as continued high quality weld process performance and inspection.

James Moll, Business Development