Trošenje kotača tračničkih vozila

master's thesis

• Title (english): Wear of rail vehicle wheels
• Author: Željko Radman
• Mentor: Krešimir Grilec (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2015-07-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Pri eksplataciji svih željezničkih vozila, neizbježan je prirodan proces habanja vijenca monobloka kotača i površine kotrljanja, koji je grubo rečeno rezultat trenja nastalim između monobloka kotača u dodiru sa tračnicom i papučom za kočenje. U ovom radu definirano je trenje kao pojava te objašnjena sama fizika trenja. Također je opisan mehanizam trenja i trošenja, pri čemu se posebno ističe trenje kotrljanja kao najčešći mehanizam trošenja uz kombinaciju s klizanjem (adhezijom). Opisan je sam tribosustav kotač/tračnica te provedena usporedba kotača s obručem i kotača iz jednog dijela (monoblok). Posebna pozornost je usmjerena na sam vijenac monoblok kotača koji je sastavni dio strukture kotača i koji sprečava iskliznuće iz tračnice pri čemu je posebice izložen trošenju i naprezanjima prilikom voženje u zavoju. Navedene su i opisane metode provjere isrotrošenosti vijenca i profila kotača, opisane su alternativne metode smanjenja njihovog trošenja, odnosno habanja te je opisana je metoda određivanja tvrdoće po Vickersu, kao važan faktor pri samom sučelju kotač/ tračnica. Eksperimentalni dio se sastojao od nabave uzorka kotača, pri čemu je provedena priprema uzorka, nakon čeka je izmjerena tvrdoća po Vickersu za rub uzoraka kako bi se utvrdila razlika tvrdoće u dijelu vijenca i glave kotača kao posljedica toplinske obrade kotača i samog trošenja. Nakon toga je određen kemijski sastav, te ispitana mikrostruktura. Na kraju je provedena analiza na osnovu dobivenih rezultata i analiza pri čemu je određena vrsta materijala samog ispitnog uzorka uporabom programskog paketa za izbor materijala (CES EduPack 2009) na osnovu dobivenih rezultata te na osnovu toga donesen zaključak.

Abstract (english)

In the exploitation of all the rolling stock, inevitable is the natural process of wear at the flange of the monoblock wheels and rolling surface, which is roughly a result of the friction occurring between the monoblock wheels in contact with the rail and the brake. In this work, friction is defined and the occurrence of physics of friction is explained. The mechanism of friction and wear is also described, in which particularly emphasizes rolling friction as the most common mechanism of wear in combination with sliding (adhesion). The tribosystem wheel/rail himself is described and the comparison between wheel with rim and wheel from one part (monoblock) is made. Special attention is directed to the flange of the monoblock wheel which is an integral part of the strukture of the wheel and which provides the wheel from sliping of the rail were it is particularly exposed to wear and stress in curves. There are listed and described verification methods of wear flang and wheel profile, and also alternative methods of reducing their expenditure. Vickers method for measuring the hardness is described, and taken as an important factor of the wheel / rail interface. The experimental part was made of the purchase of a wheel flande sample, where the sample preparation was carried out, after the measuring of the Vickers hardness at the edge and in the middle of the sample to determine the difference of the hardness at the flange of the wheel and at the body of the wheel as a result of the heat treatment and wheel wear. After that the chemical composition was determined and microstructure ecamineded. In the end, an analysis was made based on the results of the hardness and the microstruture to determinate the material of the test specimen by using an engineering programa for selecting materials (CES EduPack 2009) based on the given results and based on that adopted a conclusion.

• Keywords: monoblok kotač; vijenac; trošenje
• Keywords (english): monoblock wheel; flange; wear
• Language: croatian
• URN:NBN: urn:nbn:hr:235:503117
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 14:00:01