Utjecaj veličine abrazivnog zrna na abrazijsku otpornost nehrđajućih čeličnih ljevova

undergraduate thesis

• Title (english): Effect of abrasive grain size on the abrasive wear resistance of cast stainless steels
• Author: Robert Brkić
• Mentor: Vera Rede (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2020-02-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Osnovni cilj završnog rada bio je ispitati abrazijsku otpornost austenitnog nehrđajućeg čeličnog lijeva oznake GX5CrNi 19-10 i dupleks nehrđajućeg čeličnog lijeva oznake GX2CrNiMoN 25-6-3 te utvrditi postoji li kritična veličina abrazivnog zrna. Također je analizirana mikrostruktura i izmjerena mikrotvrdoća HV0,2.
U teorijskom dijelu rada opisani su uvjeti korozijske postojanosti čeličnih ljevova, podjela po vrstama, mikrostruktura i svojstva. Opisan je abrazijski mehanizam trošenja i objašnjen fenomen kritične veličine abrazivnog zrna.
Utvrđeno je da intenzitet trošenja kod oba lijeva ovisi o veličini abrazivnog zrna. Dupleks čelični lijev ima višu mikrotvrdoću i veću otpornost na abrazijsko trošenje od austenitnog čeličnog lijeva. Kod oba lijeva rubovi su tvrđi i manje se troše u odnosu na sredinu odljevka. Ove razlike su posljedica grublje mikrostrukture na rubu odljevaka. Kod svih ispitanih uzoraka izražen je fenomen kritične veličine abrazivnog zrna. Kritični promjer abrazivnog zrna iznosi oko 52 µm.

Abstract (english)

The objective of this paper was to investigate abrasive wear of austenitic cast stainless steel grade GX5CrNi 19-10 and duplex cast stainless steel grade GX2CrNiMoN 25-6-3 and to determine critical particle size. Microstructure and microhardness of these materials was analysed as well.
The conditions in which cast steels are corrosion resistant were described in theoretical part. Classification of cast stainless steels, their microstructure and properties, wear mechanisms and critical abrasive particle size were also explained in theoretical part of this paper.
It is determined that wear rate of both casts depends on abrasive particle size. Duplex cast steel exhibits higher microhardness and therefore higher resistance to abrasive wear than austenitic cast steel. In both casts the corners of cast steels are harder which is due to smaller grain size. Critical particle size phenomenon is present in every sample and its value is around 52 µm.

• Keywords: nehrđajući čelični ljevovi; abrazivno trošenje; kritična veličina zrna; mikrotvrdoća
• Keywords (english): cast stainless steels; abrasive wear; critical particle size; microhardness
• Language: croatian
• URN:NBN: urn:nbn:hr:235:958693
• 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: 2020-02-24 10:27:43