Metallurgical laboratory

The welding and metallurgy laboratory tests welds and welded joints using burst and non-burst tests.

The laboratory is accredited by SIST EN ISO/IEC 17025:2017 for the following investigations and tests:

  • The macroscopic examination of welds
  • Chapry impact tests
  • Flexural test
  • Break-off test
  • Vickers hardness tests
  • Transverse tensile tests

We also carry out non-accredited tests:

  • penetrant tests,
  • microscopy (particle size, micro cracking, ferrite share, etc.),
  • micro-hardness,

In cooperation with our partners, you can also order various non-destructive tests, chemical analyses of materials, corrosion tests, etc.

Metallographic testing

Metallographic testing is one of six methods for which our laboratory is accredited. In our laboratory, the samples are first prepared: cut, poured into a mass (depending on the size) and prepared for examination. The samples are then etched to achieve the desired visibility of the microstructure. We are accredited for metallographic examinations up to 50x magnification. We use Leica and Olympus stereo microscopes for testing.

Control of heat treatments

We carry out controls on heat treatments:

  • measuring the depth of the nitration layer,
  • measurements of hardness and micro-hardness,
  • 3D scanning measurements of workpiece dimensions

Hardness measurements

In the laboratory, we perform Vickers hardness measurements (HV10), another method for which we are accredited. We measure the hardness of metallic materials, check the hardness after heat treatment (quenching, tempering, annealing) and the hardness of welded joints.
We can also perform micro-hardness measurements on request (a non-accredited method).
Hardness measurements are carried out using the Zwick ZHU 2.5 Universal Hardness Tester. Hardness measurements can be carried out from HV0.2 up to HV30.
We also carry out measurements in the field with a portable hardness tester.

Tensile tests

The tensile test is a fundamental mechanical test. It determines the strength properties of metals and alloys, the yield stress (yield strength), the tensile strength and the modulus of elasticity. This numerical data can be directly applied to the strength calculations of various structural elements. Tensile tests are carried out using a Heckert EU40 machine. We are accredited for the transverse tensile testing of base material and welded joints (metallic materials and welds of metallic materials) with the determination of failure force and tensile strength. We prepare the samples for testing ourselves in our laboratory.

Toughness tests

Toughness tests are another of the accredited methods. Toughness is the property of materials before failing after deformation when acted upon by external forces. It is most often related to the impact resistance of the material (impact toughness). Impact toughness is usually measured using the Charpy test. We can test the base material and welded joints in a temperature range of -60°C to +20°C.

Overview of weld joints

When inspecting welded joints, there is both non-destructive testing (NDT) and destructive testing (DT) available. Our laboratory is accredited to carry out destructive testing in connection with the certification of welding procedures according to the standard ISO EN 15614 and the certification of welders after ISO EN 9606.

Destructive testing includes

To certify the process:

  • tensile test
  • flexural test
  • impact toughness test
  • metallographic testing
  • hardness measurement

Depending on the shape of the sample and the quality of the material, certain tests may be excluded from the scope of the tests

For the certification of welders:

  • flexural test
  • break-off test
  • metallographic testing
  • tensile test

When inspecting welds and welded joints, we can carry out a penetrant inspection before and after welding, upon request. Since cracks sometimes appear after welding or heat treatment due to material fatigue or the chemical composition of the material, which is difficult to weld, they can be detected and repaired using the penetrant method. However, penetrant testing can also be used prior to welding to pinpoint any cracks, as well as their size and depth.