Testing for Susceptibility to Hot Cracking on Gleeble™ 3500 Physical Simulator Alsalamah Bassel 1 László Kuzsella 2,a Zsolt Lukács 2,b 1 PhD Student, 2 Associate Professor University of Miskolc, Hungary, Institute of Materials Science & Technology 3515, Miskolc-Egyetemváros Phone: +36 46 565 091 - E-mail: makdekani@uni-miskolc.hu ABSTRACT Hot cracks appear when thermal shrinkage together with deformation caused by restraint cannot be accommodated by plastic deformation. This happens during welding to such alloys, which segregate on heating and cooling at near-solidus temperatures, in particular when low-melting and mechanically weak phases form and occur over a wide range of temperatures. To check for susceptibility to the liquation cracking caused by the low-melting, weak phases, hot tensile testing can be used in combination with a thermal cycle resembling that of real welding. This procedure, which can be executed on a Gleeble Thermal-Mechanical Simulator, comprises tensile testing of a number of cylindrical samples at the temperatures below solidus and determining their hot strength and ductility. An alternative to the hot tensile test during the simulated welding cycle is the Strain-Induced Crack Opening (SICO) test. INTRODUCTION During this study, I perform experimental series by GLEEBLE 3500 multifunction thermo-mechanical system with a modern physical simulator. GLEEBLE is capable of real-time simulation of various processes. My test material is ZF50 unalloyed structural steel from which I perform a test of a deformation cracking test using a chemically tested cylindrical test piece. The specimen is heated by the GLEEBLE system and then bulked. As a result of the sealing, the cross-section of the volume fraction exposed to deformation increases considerably. The test is modeled and analyzed using DEFORM finite element software. To validate physical and mathematical simulations, you must select a parameter that can be measured on the model and on the real piece. The parameters chosen by me will be the orientation of temperature and grain. The temperature is measured in the physical simulation by thermocouples welded to the test specimen. The orientation of the particle of the specimen after the physical simulation has been doubled along the length of the specimen, and then the embedding is visualized by sanding and polishing and milling. Finally, hardness measurements DOI: 10.26649/musci.2019.082 MultiScience - XXXIII. microCAD International Multidisciplinary Scientific Conference University of Miskolc, 23-24 May, 2019, ISBN 978-963-358-177-3