Open Access System for Information Sharing

Login Library

 

Thesis
Cited 0 time in webofscience Cited 0 time in scopus
Metadata Downloads

Selective Oxidation of Advanced High Strength Steels (AHSS) during Annealing in Continuous GI/GA Lines

Title
Selective Oxidation of Advanced High Strength Steels (AHSS) during Annealing in Continuous GI/GA Lines
Authors
Gong, Yong Feng
Date Issued
2010
Publisher
포항공과대학교
Abstract
The selective oxidation of Advanced High Strength Steels (AHSS), such as TRIP steels and TWIP steels, during annealing in continuous Galvanizing/Galvannealing lines was investigated. The selective oxidation of alloying elements, such as Mn, Si and Al occurred in the 10%H2+N2 atmosphere at different dew points. High Resolution Transmission Electron Microscopy (HR-TEM) with Focused Ion Beam (FIB) sample preparation and Energy Dispersive Spectrometer (EDS) was used to analyze the composition, crystal structure, morphology, size, spatial distribution and interfacial structure of the oxides on the steel surface and in the subsurface. For Si-bearing TRIP steels, after intercritical annealing in external atmosphere, two kinds of oxide layers: amorphous a-SiO2 and crystalline c-xMnO.SiO2 (12) and amorphous a-xMnO.SiO2 (x<0.9) particles were found at the MnO/steel interface. In the subsurface, a narrow Mn-depleted zone was formed due to selective oxidation of Mn. After austenitic annealing in an internal oxidation promoting atmosphere, internal MnO and crystalline c-xMnO.SiO2 (x>1) particles were formed in the Mn-depleted ferritic subsurface. MnO oxide layer was formed at the surface and no c-xMnO.SiO2 (x>2) or amorphous a-xMnO.SiO2 (x<0.9) particles were formed at the MnO/steel interface. For Al-added TWIP steel, after austenitic annealing in external oxidation atmosphere, three kinds of oxide layers were formed on the surface: an outer MnO layer, an intermediate amorphous a-xMnO.SiO2 (x<0.9) and a thin inner crystalline c-CxMnO.Al2O3 (0.8
URI
http://postech.dcollection.net/jsp/common/DcLoOrgPer.jsp?sItemId=000000545084
http://oasis.postech.ac.kr/handle/2014.oak/556
Article Type
Thesis
Files in This Item:
There are no files associated with this item.

qr_code

  • mendeley

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Views & Downloads

Browse