Weld seam inspection DIN EN 1090

Weld inspection using macroscopic and microscopic analysis is an indispensable materials science method in quality assurance, particularly for safety-relevant components and structures (pressure vessel construction, road and railway bridge construction, railway vehicle construction, pipeline construction). This weld inspection can detect defects in the weld structure, lack of fusion, penetration, insufficient penetration, cracks, and microstructural defects . This method is a destructive metallographic examination , requiring metallographic sample preparation using a wet abrasive and grinding machine (cutting, embedding, grinding, polishing, etching). Macroscopic evaluation/macro-photography is performed by manually measuring geometric dimensions such as distances and angles. A typical measurement is the A-dimension, which determines the length of the bond between the base material and the weld metal.

In 2012, a standard revision (DIN EN 1090) was carried out which significantly increased the requirements for welding and welding specialists. In particular, a welder's test and a welding procedure test (weld seam test) are a basic requirement for being allowed to carry out welding on safety-relevant parts.

All subsequent weld inspections can be performed using simple PC testing software with image acquisition and geometric measurement functions. The microscope used for weld inspection is a macro microscope with 20x magnification.

The A-dimension of a weld can be easily determined in seconds. Various software tools are available for measuring the A-dimension. Calibrated microscopes /macroscopes are required for the measurement. Proper illumination is essential for good image quality.

Macroscopic images of various weld seams

Depending on the type of component, different joints and weld seam types arise. In addition, the thicknesses of the materials to be joined vary and the types of metal can also be different.