Dupleks postupci modificiranja i prevlačenja površina

undergraduate thesis

• Title (english): Duplex surface modification and coating processes
• Author: Marko Jukić
• Mentor: Božidar Matijević (mentor)
• Committee member: Branimir Škugor (predsjednik povjerenstva)
• Committee member: Božidar Matijević (član povjerenstva)
• Committee member: Vera Rede (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-03-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U radu su opisana svojstva i primjena čelika za poboljšavanje, preciznije čelika. Opisani su različiti postupci boriranja s naglaskom na boriranje u praškastom sredstvu, odnosno u granulatu te postupak dubokog boriranja. Objašnjene su i metode mjerenja tvrdoće s naglaskom na Vickers metodu koja se koristila u ovom radu.
U eksperimentalnom dijelu rada opisan je način na koji se provelo duboko boriranje čelika C45. Izračunato je dobivanje pojedinih krivulja hlađenja koje su bile potrebne za konačan problem, a to je vrijeme potrebno za hlađenje granulata na temperaturu ispod 723 °C (A1 linije u Fe-Fe3C dijagramu). Mikroskopom su dobivene i analizirane mikrostrukture. Uzorci su nakon toga metalografski pripremljeni kako bi se mogla izmjeriti i usporediti razlika u tvrdoći boriranog i duboko boriranog uzorka. Prikazane su i efektivne dubine boridnih slojeva za oba uzorka.

Abstract (english)

This paper describes mechanical properties of low-alloy steel C45. Different methods of boriding were explained with focus on boriding using boriding powder, and boriding method with variable temperature of process called deep boriding. Different methods of hardness testing were explained too, with an accent on Vickers method.
In the experimental part the way of deep boriding of C45 steel was explained. Different cooling curves were calculated, which were needed for solving the cooling problem of a deep borided sample. The problem was to calculate time needed for the sample to cool off from 900 °C to a temperature below 723 °C (A1 line in the Fe-Fe3C diagram). Microstructure of samples were obtained and analyzed. After that, samples were metallographically prepared so the difference of hardness of both samples could be measured and compared between each other. Also, the effective depth of a boron layer for both samples was graphically shown.

• Keywords: C45; duboko boriranje; Vickers metoda
• Keywords (english): C45; deep boriding; Vickers method
• Language: croatian
• URN:NBN: urn:nbn:hr:235:775346
• Study programme: Title: Mechanical Engineering; specializations in: Design, Process and Energy Engineering, Production Engineering, Engineering Modelling and Computer Simulation, Marine Engineering, Industrial Engineering and Management, Materials Engineering; Course: Materials 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: 2022-02-28 10:48:03