Automated tensile testing in the metals industry
ArcelorMittal is the world’s leading steel-producer. At its Ghent (Belgium) plant alone, annual black and coarse plate capacity is in excess of five million tonnes. Quality assurance includes tensile testing of metal dumbbell specimens up to 16mm thick. The system used for this consists of two ZwickRoell testing machines, a specimen magazine, a cross-section measuring-device and a barcode-reader. The metal specimens are handled via a KUKA KR6 industrial robot.
The two AllroundLine materials testing machines operate at maximum nominal forces of 100 kN and 150 kN and are equipped with various extensometers for measuring extension and change in width. The makroXtens contact-type extensometer is designed for tensile, compression, flexure and cyclic tests with manual and automated testing systems. The HP version enables a closed control circuit during measurement of strain rate to ISO 6892-1 (2009) Method A1 and ASTM E 8-09 (Method B). Fine-strain measurement is available as standard and is primarily used with metals for determination of Young's modulus and the technical elastic limit. Hydraulic grips developed by ZwickRoell are used to hold the specimens.
With the non-contact videoXtens, determination of change in width in tensile tests, as required for example for r-value determination (vertical anisotropy), is also possible. Measurements are made in one, two or four cross-sectional planes. videoXtens uses a full-frame camera; the digitized image is then processed in real time.
The entire system is controlled via an industrial controller using ZwickRoell’s autoEdition 2 automation software. The use of barcodes for specimen identification makes operation very easy and convenient: simply place the specimens in the magazine, then start the test.