Wojciech Tarasiuk

The analysis of the selected processes of thermo-chemical heat treatment of 20MnCr5 steel in the context of abrasive wear

This paper presents the results of tribological tests performed on a T-11 pin-ondisc type, which made it possible to determine the intensity of abrasive wear of * Bialystok University of Technology, Faculty of Mechanical Engineering, ul. Wiejska 45C, 15-351 Białystok, Poland, e-mail: w.tarasiuk@pb.edu.pl, tel. 571 443 038. ** ML-Tech Sp. z o. o., Poland, e-mail: m.liszewski@interia.pl, tel. 535 620 033. *** Bialystok University of Technology, Faculty of Management, Department of Production Management, Poland, e-mail: b.krupicz@pb.edu.pl, tel. 85 746 98 44. **** University of Technology in Warsaw, Institute of Mechanical Engineering, Faculty of Civil Engineering, Mechanics, and Petrochemistry, Branch in Plock, Poland, e-mail: kasprzyckaewa@gmail.com, tel.(24) 367 21 15. T R I B O L O G I A 5-2016 184 steel 20MnCr5 subjected to selected thermo-chemical heat treatments. The tested steel, after the hardening and tempering process, is characterized by high endurance parameters and is used on heavily loaded machine parts. It is frequently used for elements subjected to intense abrasion. The analysis involved the following: carburizing, boronizing, and various methods of diffusion chromizing. For large loads, it is advisable to apply boronizing or carburizing with hardening. Chrome plating entails a very thin layer of increased hardness, which is characterised by a low abrasive wear resistance at high loads.

MECHANICAL PROPERTIES OF MATERIALS AND THEIR EROSIVE WEAR

In this paper, the authors analyse the impact of selected mechanical properties of materials on their erosive wear caused by a steady stream of solid particles. A wear process is a function of the material properties of two materials that interact with each other in a given environment, i.e. the construction material and the particles that cause erosion. Erosive losses occur upon reaching a critical condition of damaging an element of the material’s surface under the influence of kinetic energy that result from incident particles of an abrasive * Bialystok University of Technology, Faculty of Management, Department of Production Management, Poland, e-mail: b.krupicz@pb.edu.pl, tel. 85 746 98 44. ** ML-Tech Sp. z o. o., e-mail: m.liszewski@interia.pl, tel. 535 620 033. *** Bialystok University of Technology, Faculty of Mechanical Engineering, Poland, e-mail: w.tarasiuk@pb.edu.pl, tel. 571 443 038. T R I B O L O G I A 5-2016 86 material. It is proposed that the critical condition that accompanies the formation of erosion losses should be represented by the toughness (U) and the specific work of the deformation of the sample in the tensile strength test (W). The study involved the following materials: NC6, 42CrMo4, 20MnCr5, and S235JR.

THE IMPACT OF GAS ON THE TRIBOLOGICAL PROPERTIES OF STEEL 16MnCr5 AFTER SURFACING WITH MICRO-JET COOLING

This paper presents results of experimental research concerning the impact of an innovative method of micro-jet cooling on the padding weld performed with MAG welding. It enables to steer the parameters of weld cooling in a precise manner. Micro-jet cooling is a novel method patented in 2011. In addition, various elements, which may e.g. enhance hardness or alter tribological properties, can be entered into its top surface, depending on the applied cooling gas. The micro-jet welding method is the innovative method, which reduces the intensity of abrasive wear. The method can be used as a basic finishing or a regeneration method. An innovative technology for micro-jet is used to cool the weld surface that is, using a micro-welding jet cooling. This allows accurate and complete control of the surface structure of the deposit. The material under study was steel 16MnCr5, which was subject to the welding process with different gases of micro-jet cooling. Nitrogen and air was used as a cooling gas. The main parameter of weld assessment was wear intensity. The tests were conducted in a tribological pin-on-disc type position. T-11 pin-ondisc tester allows for indicating basic wear parameters (wear intensity, wear coefficient, wear force). Based on results of experiment the application of nitrogen in micro-jet cooling of the padding weld in the welding process of steel 16MnCr5 beneficially affects resistance to abrasive wear.

Optimization of Micro-Jet Selective Cooling After Low Alloy Steel Welding

The paper focuses on low alloy steel after an innovative welding method with selective micro-jet cooling. Weld metal deposit (WMD) was carried out for MIG process with micro-jet cooling. This method is very promising mainly because of the high amount of acicular ferrite in low alloy steel WMD. That structure corresponds with high impact on the toughness of welds. Dynamical systems of micro-jet cooling just after welding can find application in automotive industry.