As an industrialist, you would like to carry out an analysis of aluminum welds (MIG, TIG, Plasma) according to the NF EN ISO 10042 standard
What does the NF EN ISO 10042 standard say?
NF EN ISO 10042 is a welding standard that defines quality levels for defects in arc-welded aluminum and aluminum alloy joints.
It establishes dimensional acceptance criteria for weld imperfections (defects), applying to materials with a thickness greater than 0.5 mm and covering all types of welds (butt, fillet, etc.).
What is the objective of the NF EN ISO 10042 standard?
The main objective of this standard is to provide a framework for assessing the quality of aluminum welds. It is used in the drafting of application codes and as part of quality systems for the production of welded joints.
The materials and processes covered by this standard are:
- Materials: aluminum and aluminum alloys.
- Thickness: materials thicker than 0.5 mm.
- Welding processes: it applies to the most common metal inert gas arc welding processes:
- MIG welding (metal inert gas arc welding with wire electrode).
- TIG welding (metal inert gas arc welding with tungsten electrode).
- Plasma arc welding.
It does not cover metallurgical aspects of welds (such as grain size or hardness).
The FILAB laboratory supports you in compliance with the NF EN ISO 10042 standard
Why use FILAB for your aluminum welding analysis (MIG, TIG, Plasma) according to the NF EN ISO 10042 standard?
The FILAB laboratory has a state-of-the-art analytical park equipped with optical microscopes and SEM-EDX for the analysis of aluminum welds (MIG, TIG, Plasma) according to the NF EN ISO 10042 standard. The optical microscope is essential for the metallographic analysis (macrography and micrography) of welds.
Our welding expertise services
Expertise of a welding failure
Weld Diagnosis by Optical Microscopy
Macrography
Macrography uses a stereomicroscope or low-magnification microscope (up to 50x) on a cross-section of the weld, often after chemical etching.
- Purpose: to measure geometric dimensions and internal defects with high precision.
- What it can be used to assess for ISO 10042:
- Form defects (excessive thickness, insufficient penetration, blending, etc.): It allows for precise measurement of the height (h) and width (b) of these defects to compare them with specified limits.
- Internal volume defects (blow holes, inclusions): It allows for measurement of their size and distribution over the cross-sectional area (macrograph area), which is crucial for the criteria of ISO 10042.
- Effective penetration: It confirms the actual depth of fusion.
Micrography
Micrography uses a high-magnification metallographic microscope (up to 1000x) on a very finely polished and often etched cut surface.
- Purpose: to examine very small defects and the microstructure of the weld.
- What it can assess for ISO 10042:
- Microcracks: detection of very fine cracks, which may not be visible during macrography.
- Inclusions and fine porosities: characterization of defects in the micrometer range.
- Metallurgical defects: although ISO 10042:2018 does not specifically cover metallurgical aspects (such as grain size or hardness), micrographic examination is essential for comprehensive analysis (Heat Affected Zone - HAZ, intermetallic phases, segregation) and for determining the root cause of a dimensional defect.
Welding quality levels defined by standard NF EN ISO 10042
The NF EN ISO 10042 standard proposes three levels of welding quality (or requirement) designated by the symbols B, C and D, which allow it to be applied to a wide range of welded constructions:
It is crucial to note that these quality levels relate exclusively to the weld manufacturing quality, not the fitness for purpose (the final function) of the welded product. In other words, the chosen level defines the tolerance for dimensional defects, but it is not, in and of itself, an indicator of structural performance.
Therefore, the appropriate quality level (B, C, or D) must be specified by the designer or in the order specifications. This choice must be made taking into account the actual service constraints that the assembly will be subjected to (nature of static or dynamic loads, environmental conditions, etc.).
FAQ
Its objective is to specify the permissible quality levels for geometric and volume imperfections in arc-welded (MIG, TIG, Plasma) aluminum and its alloy assemblies. It provides dimensional criteria for accepting defects (such as porosity, cracks, deformations) to ensure a defined manufacturing quality.
It specifically applies to the arc welding processes designated in ISO 4063, including:
- MIG (metal inert gas arc welding - 131).
- TIG (metal inert gas arc welding - 141).
- Plasma welding (15).
It also applies to manual, mechanized, and automatic welding, and to all welding positions.
No. The standard is applicable to materials with a thickness greater than 0.5 mm. Although it is primarily designed for full penetration butt welds and fillet welds, its principles can be extended to partial penetration butt welds.
The standard proposes three levels of requirement (or severity) designated as:
- Level B: the highest (most severe). It imposes the strictest defect tolerances. Achieving this level may require costly finishing operations (grinding, TIG finishing).
- Level C: the intermediate or general level. It represents a standard quality level.
- Level D: the lowest (least severe). It is used for applications where service constraints are the least critical.
This is a key point: quality levels B, C, and D only relate to the quality of weld fabrication (i.e., the maximum permissible defect dimensions). They never prejudge the fitness for purpose (the final function) of the product. A level D product may be perfectly suited to a non-critical application, while a critical application will require a level B.
The major challenge is porosity. Aluminum is very sensitive to porosity caused by hydrogen (from moisture, oils, or the hydrated oxide layer).
ISO 10042 provides strict criteria for porosity acceptance. The criteria vary considerably between levels B, C, and D. For example, at level B, tolerances for blowholes or nests of blowholes are extremely limited, or even nonexistent in some areas.
