Jungheinrich fork-lift trucks are produced to the highest quality standards. Among the variety of test methods used for quality assurance is the test on welded joints to EN ISO 9015. To prevent cracks due to age-hardening the welded joint is heat-treated and the heat-affected zone is then subjected to Vickers hardness tests. Vickers hardness is tested in the parent metal, the heat-affected zones and along the weld line and weld metal. The indentation position must be listed with the results in the test report.
For qualification of welded joints and of the heat treatment applied to them, Jungheinrich AG uses a modern hardness testing machine supplied by leading materials testing machine manufacturer ZwickRoell. The indentation positions can be ‘taught‘ in the video image via a mouse click and their position automatically stored in the testXpert software. Different lens magnifications can be used for the teaching and the measuring, ensuring maximum image area and maximum measurement resolution. Multiple hardness traverse tests are performed automatically; all indentations are automatically made, focused and measured. The test report with the required results and data is automatically generated in the testXpert software, so that the results are available to Jungheinrich quickly and cost-efficiently.
“We use the instrument mainly to provide effective testing of weld seams from our own production line and also for goods inwards checks on the nitrided hardness and surface layer hardness of components from our suppliers,” explains Benjamin Elst of Jungheinrich’s Quality Assurance department.