CC BY
7The 30th International Conference on Advanced Laser Technologies
ALT'23
LM-I-14
Phase composition and tribological characteristics of surface layers of multicomponent iron-based alloys after laser modification in air
S.I. Yaresko1, A.T. Kozakov2, A.V. Sidashov3
1Samara Branch of P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 221 Novo-Sadovaya Str., Samara 443011, Russia 2Research Institute of Physics, Southern Federal University, 194 Stachki Ave., Rostov-on-Don 344090, Russia
3Rostov State Transport University, 2 Narodnogo Opolcheniya Sq., Rostov-on-Don 344038, Russia
E-mail address: [email protected]
The studies results of the surface layers of tool carbon (W1-7, W1-9), alloyed (DIN 150Cr14) and heat-resistant (M2, T8) steels performed by electrochemical analysis, Auger spectroscopy and XPS in combination with ion profiling after laser treatment in air are presented. For laser treatment (LT), an ytterbium quasi-continuous fiber laser with a power of up to 130 W and a pulsed Nd glass laser with a pulse energy of up to 70 J were used. The phase composition and structure of oxide films formed on the surface of multicomponent iron-based alloys after the LT were investigated, the structure of the oxide-metal interface was established, the thickness of fully oxidized layers and the thickness of the transition layer located at the boundary with an basic steel volume was determined. For tool carbon steels, the transition layer containing FeO and iron atoms is located most deeply, then a layer of Fe3O4 oxide is followed and, finally, an outer layer consisting of a mixture of FeO and Fe2O3 oxides is located near the surface (Fig. 1). The thicknesses of fully oxidized layers for W1-7 and W1-9 steels reach 100 nm. The total thickness of the oxide layer together with the transition layer is 225.0 nm. For T8 alloy steel, iron oxides and oxide of alloying elements are present in the surface layer, with tungsten and vanadium oxides located closer to the surface. The maximum thickness of the oxidized surface layer of FeO is 126 nm, the thicknesses of the oxide layers WO3, V2O5, V2O3 are 97 nm, 90 nm, 126 nm, respectively. Selective enrichment of the surface with tungsten and vanadium atoms was found, leading to hardening of the intergrain boundaries and the appearance of a local hardened layer at a depth of 90 nm.
Fig. 1. Location diagram and thickness of oxide layer on W1-7 and W1-9 steel surface
Fig. 2. Wear rate U (^m/min) of a tool made of T8 steel: 1 - without LT; 2 - LT in air; 3 - LT in the Ar medium
It is shown that the presence of Fe2O3 and Fe3O4 oxides provides a higher wear resistance of the W1-9 steel surface after LT during nanotribo tests. For high-speed steel T8, the presence of oxides on the surface after LT affects its frictional properties and determines the stable flow of the cutting process and the stable operation of the tool (Fig. 2).
Kozakov A.T. is grateful for the financial support the Ministry of Science and Higher Education of the Russian Federation (State assignment in the field of scientific activity 2023 r. №FENW-2023-0014).
