TY - JOUR N2 - The paper presents a description of the phenomena occurring on the surface of the forging dies. A detailed analysis was made of 24 pre-forging dies due to the most intensive wear in this operation. To compare the results, new tools were also analysed. The research described in the study showed that the most dangerous factor for the hot forging process analysed is thermal-mechanical fatigue, which causes small cracks, which in turn quickly leads to the formation of a crack network on the entire contact surface of the tool with forged material. The second phenomenon is the tempering of the surface of the material for a long-term temperature effect. The presence of hard iron oxides in the form of scale from forging material is the accompanying phenomenon that intensifies the processes of tool wear. The paper presents the results of the analysis of the presence of residual magnetic field for forging tools and the results of laboratory tests of wear processes of tool steels for hot work in the presence of a magnetic field and in the presence of scale. L1 - http://www.czasopisma.pan.pl/Content/110167/PDF/AMM-2019-1-45-Zwierzchowski.pdf L2 - http://www.czasopisma.pan.pl/Content/110167 PY - 2019 IS - No 1 EP - 324 DO - 10.24425/amm.2019.126254 KW - hot die forging KW - wear mechanism KW - magnetic field KW - durability A1 - Zwierzchowski, M. PB - Institute of Metallurgy and Materials Science of Polish Academy of Sciences PB - Committee of Materials Engineering and Metallurgy of Polish Academy of Sciences VL - vol. 64 DA - 2019.03.14 T1 - Impact of tool magnetization on changes in the surface layer of forging tools SP - 317 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/110167 T2 - Archives of Metallurgy and Materials ER -