PT Journal AU Brabec, J Jezek, S Benes, L Kriz, A Majrich, P TI Suitability Confirmation for Welding Ultra-High Strength Steel S1100QL Using the RapidWeld Method SO Manufacturing Technology Journal PY 2021 BP 29 EP 36 VL 21 IS 1 DI 10.21062/mft.2021.014 DE High strength steel; t8/5; square groove welding; RapidWeld; S1100QL AB This experiment assesses the suitability of square-welding high strength steel using the deep penetra-tion welding method, RapidWeld. The aim of this method suitability assessment was to compare the final material properties of three welds, welded accordingly to identical welding procedures. High strength, ultra-fine-grain steel S1100QL (XABO 1100) was used as a parent metal. The suitability con-firmation was based on the achievement of requested mechanical properties of ISO 15614-1 and mo-bile crane manufactures standards. The hardness, strength properties and impact energy measure-ment and evaluatioon of the joint was performed during the experiment. The joint was welded re-peatedly with the use of the same welding parameters for the confirmation of process stability. The achieved mechanical properties fulfill all the requirements. The hardness value deviation is caused by different properties in the heat affected zone. The root cause of the impact energy deviaton was not fully investigated, but the minimal measured values are above requirement. The deviation of the strength characteristics is mininal. The performed experiment has confirmed that the selected weld-ing method is suitable to ensure that the requested material properties of welded high strength, ultra-fine-grained steel are achieved. ER