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SLV – Schweißtechnische Lehr- und Versuchsanstalten
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Weldability test

Weldability test on old steel

Within the framework of restoration projects on old structures (e.g. old building and bridge structures) which, as a rule, are associated with the partial replacement of materials and the reinforcement of the existing structure, it is necessary to make a statement about the weldability of the existing material. The most cost-favourable possibility of carrying out the work is to weld the existing structure with the new steel sections.

However, it is firstly necessary to clarify the question of whether the existing structure exhibits sufficient weldability in order to prevent any cracks (e.g. hot cracks) in the materials. For this reason, an "old steel" (this includes the reinforcing steels) is designated as a steel which was manufactured from approx. 1850 to 1950. The presence of an old steel structure in an existing structure does not simultaneously mean that there is no weldability.

You need the following investigations in order to clarify the weldability of old steels:

1. Sulphur print according to Baumann

2. Spark spectral analysis

For you, we also determine the weldability of modern materials if, for example, you are not in possession of a 3.1 acceptance test certificate or you would like to check it. As a rule, chemical analysis by means of spark spectral analysis is sufficient for this purpose.

Get in touch with us. As a competent partner, we will be happy to advise you with regard to your construction project too.

Materials qualification / weldability test

Customers frequently ask component and input material manufacturers to prove the weldability of their products. Then, it is necessary to produce and test trial welds.

For both activities, competent personnel and accredited testing laboratories are available at SLV Duisburg. With regard to the weld execution and the test programme, we are oriented to your stipulations, depending on whether you must fulfil a special customer specification or work according to recognised standards.

Standards according to which we carry out weldability tests are, for example:

  • DIN EN 10225: Weldable structural steels for fixed offshore structures
  • SEP 1220: Joinability of thin sheet of steel



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