Effect of sulphur on wettability of liquid Fe-0.45% C with alumina

Bajželj, Anže (author), Balaško, Tilen (author), Burja, Jaka (author)

Non-metallic inclusions, particularly alumina (Al$_2$O$_3$), pose significant challenges in steelmaking. Their behaviour in molten steel is largely governed by wettability. This study investigates the effect of sulphur, a surface-active element, on the wettability between liquid Fe-0.45%C and alumina substrates, to improve the understanding of alumina non-metallic inclusion formation in medium carbon steel. Experiments were conducted using the sessile drop method in a high-temperature melting microscope. Three Fe-0.45%C samples with varying sulphur contents (0.0020,0.0120, and 0.0340w/%) were placed on polished single-crystal alumina substrates and heated to 1600 °C in a purified argon atmosphere. Results show that increasing sulphur content in the Fe-0.45%C melt decreases the contact angle with alumina substrates from 106.5° (0.0020w/% S) to 102.0° (0.0340w/% S). Furthermore, sulphur addition increases the influence of temperature leading to a clearer trend of decreasing contact angle values as temperature rises. This implies an increased risk of solid alumina non-metallic inclusion formation if the sulphur content is elevated.

• Language: English
• Keywords: wettability, contact angle, non-metallic inclusions, surface-active elements
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Publication status: Published
• Publication version: Version of Record
• Article acceptance date: 24.09.2026
• Publication date: 01.11.2025
• Year: 2025
• Number of pages: str. 839-843
• Numbering: Letn. 59, št. 6
• PID: 20.500.12556/RUL-179449
• UDC: 544.722.3:691.714:666.762.11
• ISSN on article: 1580-2949
• DOI: 10.17222/mit.2025.1542
• COBISS.SI-ID: 261774851
• Publication date in RUL: 17.02.2026

Record is a part of a journal

• Title: Materiali in tehnologije
• Shortened title: Mater. tehnol.
• Publisher: Inštitut za kovinske materiale in tehnologije
• ISSN: 1580-2949
• COBISS.SI-ID: 106193664

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Title: Vpliv žvepla na omočljivost taline zlitine Fe-0.45% C z aluminijevim oksidom

Abstract

Nekovinski vključki, zlasti aluminijev oksid (Al2O3), predstavljajo velik izziv v jeklarstvu. Njihovo obnašanje v talini jekla je v veliki meri odvisno od omočljivosti. Ta študija preiskuje vpliv žvepla, površinsko aktivnega elementa, na omočljivost med talino zlitine Fe-0,45%C in podlago iz Al2O3, z namenom izboljšati razumevanje nastajanja nekovinskih vključkov alumina v srednjeogljičnem jeklu. Eksperimenti so bili izvedeni z metodo sesilne kapljice v visokotemperaturnem talilnem mikroskopu. Trije vzorci zlitine Fe-0,45%C z različnimi vsebnostmi žvepla (0,0020w/%, 0,0120w/%in 0,0340w/%S) so bili postavljeni na polirane monokristalne podlage iz aluminijevega oksida in segreti na 1600 °C v zaščitni atmosferi argona. Rezultati kažejo, da naraščajoča vsebnost žvepla v talini Fe-0,45%C zmanjšuje kot omočenja s podlagami Al2O3, in sicer s 106,5° (pri 0,0020w/%S) na 102,0° (pri 0,0340w/%S). Poleg tega dodatek žvepla poveča vpliv temperature, kar vodi do izrazitejšega trenda zmanjševanja vrednosti kota omočenja z naraščajočo temperaturo. To pomeni povečano tveganje za nastanek trdnih nekovinskih vključkov aluminijevega oksida pri povišani vsebnosti žvepla.

• Keywords: omočljivost, kot omočenja, nekovinski vključki, površinsko aktivni elementi

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: Young Researcher program
• Name: Young Researcher program

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0050-2018
• Name: Kovinski materiali in tehnologije