TY - JOUR N2 - The study presents a durability analysis of dies used in the first operation of producing a valve-type forging from high nickel steel assigned to be applied in motor truck engines. The analyzed process of producing exhaust valves is realized in the forward extrusion technology and next through forging in closed dies. It is difficult to master, mainly due to the increased adhesion of the charge material (high nickel steel) to the tool’s substrate. The mean durability of tools made of tool steel W360, subjected to thermal treatment and nitriding, equals about 1000 forgings. In order to perform a thorough analysis, complex investigations were carried out, which included: a macroscopic analysis combined with laser scanning, numerical modelling by FEM, microstructural tests on a scanning electron microscopy and light microscopy (metallographic), as well as hardness tests. The preliminary results showed the presence of traces of abrasive wear, fatigue cracks as well as traces of adhesive wear and plastic deformation on the surface of the dies. Also, the effect of the forging material being stuck to the tool surface was observed, caused by the excessive friction in the forging’s contact with the tool and the presence of intermetallic phases in the nickel-chromium steel. The obtained results demonstrated numerous tool cracks, excessive friction, especially in the area of sectional reduction, as well as sticking of the forging material, which, with insufficient control of the tribological conditions, may be the cause of premature wear of the dies. L1 - http://journals.pan.pl/Content/109172/PDF/AMM-2018-4-53-Hawryluk.pdf L2 - http://journals.pan.pl/Content/109172 PY - 2018 IS - No 4 EP - 1974 DO - 10.24425/amm.2018.125131 KW - tool wear KW - tools durability KW - destructive mechanisms KW - valve engine KW - high nickel steel A1 - Hawryluk, M. A1 - Gronostajski, Z. A1 - Kaszuba, M. A1 - Krawczyk, J. A1 - Widomski, P. A1 - Ziemba, J. A1 - Zwierzchowski, M. A1 - Janik, J. 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. 63 DA - 2018.12.12 T1 - Wear Mechanisms Analysis of Dies Used in the Process of Hot Forging a Valve Made of High Nickel Steel SP - 1963 UR - http://journals.pan.pl/dlibra/publication/edition/109172 T2 - Archives of Metallurgy and Materials ER -