20.500.12556/DiRROS-18286 Enhancing ductility of hot-work tool steel through isothermal bainitic transformation Hot-work tool steels are extensively used in industrial applications that require high resistance to mechanical and chemical degradation at elevated temperatures. To meet these requirements, hot-work tool steels must exhibit good mechanical properties, including high tensile strength, hardness, wear resistance, and tempering resistance, as well as high thermal conductivity and ductility. This study investigates the ductility of the hot-work tool steel HTCS-130, which suffers from low ductility due to the presence of stable molybdenum-tungsten carbides (M6C) on the prior austenite crystal grain boundaries. Increasing austenitisation temperatures or prolonging the dwelling time at temperature can promote intensive migration of grain boundaries, leading to negative effects on the mechanical properties of the steel. To address this issue, isothermal transformation in the bainitic area between 350 and 500 °C was performed. Isothermal transformation at around 350 °C leads to the formation of lower bainite, which has similar hardness to tempered martensite. As the temperature of isothermal transformation increases, the hardness of the material decreases, due to the formation of upper bainite. The hardness analysis was measured using the Vickers method, the impact toughness of the steel samples was measured using a Charpy test with V-notched samples. The microstructure characterization was performed using optical and scanning electron microscopy. The improvement of ductility can be achieved by controlling the isothermal transformation of bainite and adjusting the heat treatment conHot-work tool steels are extensively used in industrial applications that require high resistance to mechanical and chemical degradation at elevated temperatures. To meet these requirements, hot-work tool steels must exhibit good mechanical properties, including high tensile strength, hardness, wear resistance, and tempering resistance, as well as high thermal conductivity and ductility. This study investigates the ductility of the hot-work tool steel HTCS-130, which suffers from low ductility due to the presence of stable molybdenum-tungsten carbides (M6C) on the prior austenite crystal grain boundaries. Increasing austenitisation temperatures or prolonging the dwelling time at temperature can promote intensive migration of grain boundaries, leading to negative effects on the mechanical properties of the steel. To address this issue, isothermal transformation in the bainitic area between 350 and 500 °C was performed. Isothermal transformation at around 350 °C leads to the formation of lower bainite, which has similar hardness to tempered martensite. As the temperature of isothermal transformation increases, the hardness of the material decreases, due to the formation of upper bainite. The hardness analysis was measured using the Vickers method, the impact toughness of the steel samples was measured using a Charpy test with V-notched samples. The microstructure characterization was performed using optical and scanning electron microscopy. The improvement of ductility can be achieved by controlling the isothermal transformation of bainite and adjusting the heat treatment conditions. These findings provide useful insights into the design and optimization of heat treatment processes for hot-work tool steels.ditions. These findings provide useful insights into the design and optimization of heat treatment processes for hot-work tool steels. hot-work tool steel austempering bainitic transformation ductility dilatometry orodna jekla za delo v vročem austempranje bainitna transformacija duktilnost dilatometrija true false true TANGER Češka Angleški jezik Slovenski jezik Licenca Creative Commons je navedena na pristajalni strani članka (glej izvorni URL): "© This is an open access article distributed under the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/)". (Datum opombe 4. 4. 2023) Neznano 2024-02-28 13:22:28 2024-02-28 13:22:29 2024-04-04 11:04:58 0000-00-00 00:00:00 2024 0 0 Nasl. z nasl. zaslona; Opis vira z dne 14. 2. 2024; Str. 308-314 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 669.14 2694-9296 10.37904/metal.2023.4703 185399299 185388291 RAZ_Bajzelj_Anze_2024.pdf RAZ_Bajzelj_Anze_2024.pdf 1 EADAA8E495A06DD36A759D32897534A5 38a65e492db5359bb38b511732df634d12851c9ae3dc0462304816c14b38b692 58c120ac-d631-11ee-900a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=24843 https://www.confer.cz/metal/2023/4703-enhancing-ductility-of-hot-work-tool-steel-through-isothermal-bainitic-transformation 0 8000985e-d631-11ee-900a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=24844 Inštitut za kovinske materiale in tehnologije 0 0 0