Change search
ReferencesLink to record
Permanent link

Direct link
Oxide layer thickness modification of a dual phase steel by steam treatment
2012 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

Low carbon steels have good mechanical properties that are utilised in various applications around the world. Dual phase steel structures consisting of ferrite and martensite provide a good combination of strength, formability and weldability. Under certain conditions, a desirable oxide layer can be formed on the base material, which improves the wear and corrosion properties. Black oxidation treatment is a metal finishing process, used to create an oxide layer on steels. The high temperature oxidation treatment also influences the mechanical properties of the steel by simultaneous annealing of the steel. In this work laboratory experiments simulating a black oxidizing treatment in industry have been performed. The dew points of water vapour, operation temperature, time of oxidation, partial pressure of oxygen and gas flow rate have been varied in the experiments. The analysis methods for determining the microstructure that have been used are optical microscopy (OM) and scanning electron microscopy (SEM). The composition of the oxide and base material was analysed using x-ray energy dispersive spectroscopy (EDS). The surface roughness of the oxide surface was determined by topographical profilometry. Hardness testing of cross sections of the final samples was also performed. The results showed that a higher dew point gives a thicker oxide layer. This is a result of higher water vapour content and water vapour pressure, which produces a higher partial pressure of oxygen in the system, enabling more oxygen to interact with the base material. With certain temperatures and oxidation treatment times the oxide layer thickness is influenced, as is the hardness of the material, which will become softer.

Place, publisher, year, edition, pages
Keyword [en]
Keyword [sv]
URN: urn:nbn:se:ltu:diva-49870Local ID: 730028d0-2ef6-4c57-ab2b-724d2ec3cba8OAI: diva2:1023218
Subject / course
Student thesis, at least 30 credits
Educational program
Materials Engineering, master's level
Validerat; 20120626 (anonymous)Available from: 2016-10-04 Created: 2016-10-04Bibliographically approved

Open Access in DiVA

fulltext(5116 kB)0 downloads
File information
File name FULLTEXT02.pdfFile size 5116 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Zhang, Chu

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

ReferencesLink to record
Permanent link

Direct link