Najnovija saznanja o postupcima pasivacije nehrđajućih čelika

undergraduate thesis

• Title (english): State-of-the art in passivation processes for stainless steels
• Author: Luka Eter
• Mentor: Sanja Martinez (mentor)
• Committee member: Sanja Martinez (predsjednik povjerenstva)
• Committee member: Helena Otmačić Ćurković (član povjerenstva)
• Committee member: Šime Ukić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Korozija predstavlja kemijski proces koji dovodi do oštećenja i degradacije metala. Brzina i vrsta korozije variraju ovisno o vrsti metala, upotrijebljenim materijalima te primijenjenim mjerama zaštite. Jedan od materijala koji je s početkom 20. stoljeća privukao veliku pozornost zbog svoje iznimne otpornosti prema koroziji jest nehrđajući čelik. Ova otpornost proizlazi iz korozijske otpornosti zaštitnog oksidnog sloja na površini koja se može dodatno unaprijediti različitim metodama. Metode pasivacije nehrđajućeg čelika zaslužuju posebnu pažnju zbog svoje široke primjene u raznim industrijama. U ovom radu istražene su nove obećavajuće metode pasivacije nehrđajućeg čelika, kao što su SMAT (Surface Mechanical Attrition Treatment) i PISG (Plasma Immersion Ion Implantation and Deposition). Ovim metodama postiže se visoka otpornost nehrđajućeg čelika na koroziju putem obrade površine. Također, u radu je razmotreno elektropoliranje, jer omogućuje stvaranje glatke i sjajne površine koja također pridonosi otpornosti na koroziju. Važno je napomenuti da se pasivacija nehrđajućeg čelika danas najčešće provodi upotrebom dušične kiseline. Međutim, ovaj proces smatra se štetnim za okoliš, pa je u radu napravljena usporedba alternativnog ekološki prihvatljivijeg procesa pasivacije limunskom kiselinom i procesa provedenog s pomoću dušične kiseline. Ovaj rad pruža uvid u nove tehnike pasivacije nehrđajućeg čelika, istražuje njihove prednosti i potencijal za smanjenje negativnog utjecaja na okoliš.

Abstract (english)

Corrosion is a chemical process that leads to damage and degradation of metal. The rate and type of corrosion vary depending on the type of metal, the materials used and the protection measures applied. One of the materials that attracted a lot of attention at the beginning of the 20th century due to its exceptional resistance to corrosion is stainless steel. This resistance results from the corrosion resistance of the protective oxide layer on the surface, which can be further improved by various methods. Stainless steel passivation methods deserve special attention due to their wide application in various industries. In this paper, new promising methods of stainless steel passivation, such as SMAT (Surface Mechanical Attrition Treatment) and PISG (Plasma Immersion Ion Implantation and Deposition) are investigated. These methods achieve a high resistance of stainless steel to corrosion through surface treatment. Also, electropolishing is considered in the work, because it enables the creation of a smooth and shiny surface, which also contributes to corrosion resistance. It is important to note that the passivation of stainless steel today is most often carried out using nitric acid. However, this process is considered important for the environment, and a comparison of an alternative, more ecologically acceptable passivation process with citric acid and a process carried out using nitric acid was hereby made. This works provides an insight into new stainless steel passivation techniques, explores their advantages and potential for reducing the negative impact on the environment.

• Keywords: pasivacija; nehrđajući čelik; korozija; SMAT; PISG
• Keywords (english): passivation; stainless steel; corrosion; SMAT; PISG
• Language: croatian
• URN:NBN: urn:nbn:hr:149:203162
• Study programme: Title: Applied Chemistry - Undergraduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-11-28 14:35:03