Quality Control

During non-destructive testing of materials (NDT), all tests are carried out in a manner which does not allow even the smallest breach or damage the tested piece.

For tests of surface homogeneity, imperfections are searched for using a magnetic or penetration method.

For tests of internal homogeneity, internal imperfections are searched for using ultrasonic or radiographic method.

NDT tests:

• Ultrasonic testing of sheets, cut parts, welds, castings and special components,
• X-ray testing up to a material thickness of 65 mm,
• magnetic control,
• penetration method,
• measuring of wall thickness with an ultrasonic detector.

Non-destructive testing of materials is performed by trained personnel, whose qualifications are regularly verified by an independent certification organization in accordance with EN ISO 9712 at Level II.

The UNEX test laboratories perform complete analyses of chemical, mechanical and metallographic properties of steels and cast irons for internal needs of the company, but also external customers. The test laboratory in the Uničov plant is a component of a system certified according to ISO 9001:2008, member of an international association of measuring, testing and analytical laboratories Eurolab-CZ and member of the Association of Czech Test Laboratories with audited activities. It regularly participates in inter-laboratory tests in order to ensure proper quality of the results.

Chemical laboratory

It makes analyses of chemical compositions of all types of steels and cast irons by application of optical emission spectrometry and combustion analysis (C, S). It also makes analyses of selected input materials and ferro-alloys using an analytic method.

Chemical analyses utilize a modern spectrometer ARL 44 60 with SparkDate for analyses of inclusions and a combustion gas analyser Leco CS225.

We are able to perform a quick analysis of chemical composition directly on the product by means of a portable X-ray analyser X-MET 7500.

Mechanical testing facility

Testing mechanical properties of steels, alloys and non-ferrous metals:

• Tensile test at normal temperature (determination of Rm, Re, Rp0.2, A5, Z),
• impact test at normal temperature,
• impact test at lower temperature (up to -60 °C),
• bend test,
• Brinell (HB), Vickers (HV), Rockwell (HRC) hardness tests,
• weld hardness testing.

The mechanical properties are tested by the currently most advanced testing machine ZWICK Z 400E, notch toughness is tested by the Charpy hammer PS 30 and HB, HRC and HV hardness is measured by the reliable stable hardness testers VEB WPM Leipzig.

Mechanical workshop – machining of samples
Production of testing bodies is ensured via delivered testing samples in agreement with the conditions and requirements of technical standards or the customers' technical specifications for mechanical testing.

Metallographic laboratory

Evaluation of metallographic structure of material:

• Ensuring evaluation of the microstructure for retesting of the accuracy of heat-treatment,
• determining micro-fineness of material,
• determining grain size,
• evaluation of cast iron,
• determining decarburisation,
• evaluation of surface hardened, cemented layers,
• quantitative appraisal,
• evaluation of defects of parts.

The micro structure is checked and evaluated by an optical microscope Neophot 32 with application of the Quick PHOTO Industrial 2.2 programme.

Sand laboratory

Monitoring, checking and evaluation of the quality of moulding mixtures using operating machines in sand laboratories.

The 3D method is particularly suitable for measurements which cannot be performed with classic gauges or where the use of classic gauges increases measurement error. We offer measuring with:

3D coordinate measuring machine Contura G2

• max. workpiece height 1,000 mm, max. workpiece length 1,600 mm, workpiece width 600 mm,
• max. workpiece weight 1,000 kg (exceptionally even more, depending on the shape and handling possibilities),
• achieved accuracy of measuring up to 0.001 mm (depends on the shape of the workpiece and the used measuring method).

3D coordinate measuring system Leica