Toughness Examination of Physically Simulated S960QL HAZ by a Special Drilled Specimen
Based on the welding heat cycle models physical simulators are capable for the creation of critical heat-affected zones (HAZ). The simulated HAZ areas can be examined by various material testing methods (e. g. Charpy V-notch impact test) due to their increased homogeneous volume compared to their extension in real welding experiments. In our research work relevant technological variants (t 8.5/5 = 2.5…30 s) for gas metal arc welding technology were applied during the HAZ simulation of S960QL steel (EN 10025-6), and the effect of cooling time on the coarse-grained HAZ was analysed. In thermo-mechanical simulators the achievable cooling rate is always the function of specimen geometry and the presence of external cooling. Therefore a special drilled specimen with external cooling was developed for performing a shorter (t 8.5/5 = 2.5 s) cooling than 5 s, which cannot be realized on the conventional Gleeble specimen. Heat cycles were determined according to the Rykalin 3D model. The properties of the selected coarse-grained (CGHAZ) zone were investigated by scanning electron microscope, hardness test and Charpy V-notch impact test.
KeywordsHigh Strength Steel Cool Time Specimen Geometry External Cool Welding Heat Input
The research work presented in this paper based on the results achieved within the TÁMOP-4.2.1.B-10/2/KONV-2010-0001 and TÁMOP-4.2.2.A-11/1/KONV-2012-0029 projects in the framework of the New Széchenyi Plan. The realization of these projects was supported by the European Union, and co-financed by the European Social Fund.
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