Applying Surface Plasma Hardening for Improving The Tribological Characteristics of Steel Parts

Abstract

This work presents the results of experimental studies on the application of surface plasma hardening to improve the tribological characteristics of steel marks of 40CrNi, 20Cr2Ni4A, and 34CrNi1Mn. According to the obtained results, it was established that, after plasma treatment, a modified layer with a thickness of 1-1.2 mm with high hardness and wear resistance is formed, consisting of a hardened layer of fine-grained martensite and, an intermediate layer of perlite and martensite. It was determined that, after treatment with a heating time of 3 min, the microhardness of steels 40CrNi and 20Cr2Ni4A doubles, and the steel 34CrNi1Mn increases 1.6 times, depending on the initial state, and the wear resistance of all steel samples increases, on average, 30 times. słowa kluczowe: utwardzanie plazmowe, mikrotwardość, odporność na zużycie, modyfikowana warstwa powierzchniowa, martenzyt, austenit szczątkowy, współczynnik tarcia, zużycie. StreszczenieW niniejszej pracy przedstawiono wyniki eksperymentalnych badań nad stosowaniem utwardzania plazmy powierzchniowej w celu poprawy charakterystyki tribologicznej próbek stalowych 40CrNi, 20Cr2Ni4A i 34CrNi1Mn. Zgodnie z uzyskanymi wynikami ustalono, że po obróbce plazmowej powstaje zmodyfikowana warstwa o grubości 1-1,2 mm o dużej twardości i odporności na ścieranie, składająca się z utwardzonej warstwy drobnoziarnistego martenzytu i warstwy pośredniej z perlitu i martenzytu. Stwierdzono, że po obróbce z czasem ogrzewania 3 min mikrotwardość stali 40CrNi i 20Cr2Ni4A podwaja się, a stal 34CrNi1Mn wzrasta 1,6 razy, w zależności od stanu początkowego, i odporność na zużycie wszystkich próbek stali wzrasta średnio 30 razy.

Reserach of the mechanic-tribological characteristics of Ti3SiC2/TiC coatings after annealing

“…The study of the surface microstructure was carried out on a scanning electron microscope Vega3 Tescan. Tribological sliding friction tests were carried out on a tribometer THT-S-BE-0000 using the standard "ball-disk" technique (international standards ASTM G 133-95 and ASTM G 99) [10,11]. As a counterbody, a VK ball with a diameter of 3 mm was used.…”

INFLUENCE OF PLASMA ELECTROLYTIC HARDENING ON THE STRUCTURE AND PROPERTIES OF 20Cr2Ni4A STEEL

“…Table 1 presents the chemical composition of the investigated steel. PEH of steel samples was performed on the unit IEPPM-M (installation for electrolytic-plasma processing of materials -modernized), which was designed and manufactured by the authors at the Research Center "Surface Engineering and Tribology" of S. Amanzholova EKSU [9][10][11]. The PEH process was carried out in an electrolyte from an aqueous solution containing 20 % sodium carbonate and 20% urea in the following mode: the applied voltage between the anode and the sample -320 V, the current density -25 A/cm 2 , and the plasma exposure time -2 s. In this mode, the samples were heated to ~ 850-900 °C.…”

“…It is possible to produce hardening, chemicalthermal and thermal-cyclic processing of materials which depending on the heating mode, electrolyte composition, design parameters of the equipment. The last decade is actively studying the effect of electrolyteplasma nitriding, cementation and carbonitriding on the structure and properties of steels [7][8][9][10][11]. Nevertheless, many physical processes are still not well understood, for example, phase transformation processes during electrolytic-plzmennoy surface hardening and their influence on tribomechanical properties.…”