Vývoj technologie odběru zkušebních vzorků pro zkoušky mechanických vlastností pomocí jádrování

Abstract

TREFIL, Antonín. Technology Development of Test Samples for Mechanical Properties Testing using Coring. Ostrava, 2018. 90s. Dissertation Thesis. VŠB – Technical university of Ostrava. Thesis supervisit: Assoc. Prof. Robert Čep, Ph.D., MSc

The verification of mechanical properties is essential for each machine component. Depending on the future use of the component, the requirements for its mechanical properties are also specified such as hardness, toughness, abrasion resistance, etc. Segment from semi-finished product is essential for manufacturing test specimens and subsequent mechanical testing. Teoretical part of the thesis very briefly describes mechanical test methods (tensile test, Charpy impact test). Shapes and dimensions of specimens are described according to valid standard. The current methods of sampling on the forging shop was also studied. The work deals with sampling of test segments for mechanical testing on heavy forgings (from about two up to several tens of tons) by core drilling technology. Core drilling tools require rigidity of the machining systém – M-T-W (machine-tool- workpiece) with sufficient pressure support and flow media process support. By changing the tool design or the geometry of the cutting tool insert it is possible to prove the use of this technology also in the forging shops with mobile devices. These are the use of mobile (assembly) machines, the provision of process media and the above-mentioned tool modifications. In the future this would entail a substantial reduction in the cost of manufacturing the parts due to the removal of large quantities (according to the shape of the component) of the test material on the forgings and also the expensive transport of these heavy forgings to the sampling workplace. It is not only about transporting components to the sampling workplace but also about back transporting due to quality heat treatment in case on insufficient mechanical values. The results of experimental work are the concrete conclusions for the use of the proposed technology in practice. The final evaluation summarizes the benefits of a new solution for the sampling of test segments in forging shops.