Ispitivanje trošenja alata kod obrade čelika za izradu prstenova kotrljajućih ležaja

undergraduate thesis

• Title (english): Examination of the tool wear on machining of steel of the bearing rings
• Author: Matija Pisk
• Mentor: Božidar Matijević (mentor)
• Mentor: Ivan Kumić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2019-02-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Prilikom izrade prstenova kotrljajućih ležajeva najčešće se primjenjuju čelici kvalitete 100Cr6, 80CrMn4 ili 100CrMnS6-4. Sama izrada prstenova provodi se na različitim tokarilicama uz primjenu različitih oblika i kvaliteta reznih pločica. Kako se radi o velikoserijskoj ili masovnoj proizvodnji prstenova kotrljajućih ležajeva tako je i potrošnja reznih pločica također velika. Iz tog razloga važno je odabirom kvalitetnih pločica utjecati na troškove izrade prstenova kotrljajućih ležajeva. Kako danas na tržištu imamo različite proizvođače reznih pločica različitih kvaliteta (sastava osnovnog materijala, prevučene različitim slojevima) potrebno je prateći trošenje i analizom reznih pločica, zaključiti o kvaliteti istih. U ovom radu provedena su ispitivanja na istrošenim reznim pločicama koje su napravljene od tvrdog metala i prevučene funkcionalnim prevlakama. Primjenom kalotestera izmjerena je debljina prevlake. Utiskivanjem i analizom otiska Rockwell C indentorom utvrđena je adhezivnost prevlake. Nanoindentacijom je određena tvrdoća osnovnog materijala i prevlake, dok je Palmqvistovom metodom određena lomna žilavost osnovnog materijala. Metalografskim ispitivanjem poprečnog presjeka provjerena je mikrostruktura osnovnog materijala te su dobiveni rezultati stavljeni u kontekst trajnosti reznog alata.

Abstract (english)

In the manufacturing of rolling bearings rings, materials like 100Cr6, 80CrMn4 or 100CrMnS6-4 are most commonly used. Bearing rings are generally manufactured using machining techniques like turning, in which cutting tools with different geometry and quality are applied. This industry being high volume production, uses large quantities of aforementioned cutting tools. By using cutting tools of different quality, it is possible to cut down on production costs in manufacturing of rolling bearing rings. In this research, coated cemented carbide cutting tools were tested using different analytical methods. Thickness of functional coatings was measured using calotest. Coating adherence to the substrate was analysed by Rockwell C indentation. Nano-hardness was tested using the instrumented method for hardness testing, while the fracture toughness of substrate was determined by Palmqvist method. Microstrucutre in cross section was metallographicly analysed, and all of the results were interpreted trough the longevity of cutting tools in real life application.

• Keywords: tvrdi metali; funkcionalne prevlake; tokarenje; analiza kvalitete alata
• Keywords (english): cemented carbides; coatings; machining turning; tool quality analysis
• Language: croatian
• URN:NBN: urn:nbn:hr:235:522611
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-23 00:04:45