Heat affected zone microstructures and their influence on toughness in two microalloyed HSLA steels

Hutchinson, Bevis, Komenda, Jacek, Rohrer, Gregory S. and Beladi, Hossein 2015, Heat affected zone microstructures and their influence on toughness in two microalloyed HSLA steels, Acta materialia, vol. 97, pp. 380-391, doi: 10.1016/j.actamat.2015.05.055.

Attached Files
Name Description MIMEType Size Downloads

Title Heat affected zone microstructures and their influence on toughness in two microalloyed HSLA steels
Author(s) Hutchinson, Bevis
Komenda, Jacek
Rohrer, Gregory S.
Beladi, HosseinORCID iD for Beladi, Hossein orcid.org/0000-0003-0131-707X
Journal name Acta materialia
Volume number 97
Start page 380
End page 391
Total pages 12
Publisher Elsevier
Place of publication Amsterdam, The Netherlands
Publication date 2015-07-17
ISSN 1359-6454
Keyword(s) Bainite
EBSD
Heat affected zone
Inter-variant plane distribution
Toughness
Summary Microstructures and Charpy impact properties have been examined in two microalloyed steels following heat treatments to simulate weld heat affected zone (HAZ) structures over a range of heat input conditions, characterised by the cooling time from 800 to 500°C (Δt8/5). The base materials were low carbon structural steel plates microalloyed with vanadium and nitrogen (V-N) and niobium (Nb), respectively. The toughnesses of the HAZs displayed remarkably different behaviours as shown by their impact transition temperatures. For the V-N steel, the toughness improved with increasingly rapid cooling (low heat input conditions) whereas the Nb steel showed an opposite trend. Some of this behaviour could be explained by the presence of coarse ferrite grains in the slowly cooled V-N steel. However, other conditions where all the structures were bainitic and rather similar in optical micrographs gave widely different toughness values. The recently developed method of five dimensional boundary analysis based on electron backscattering diffraction has been applied to these cases for the first time. This showed that the lath boundaries in the bainite were predominantly on {1 1 0} planes of the ferrite and that the average spacing of these boundaries varied depending on steel composition and cooling rate. Since {1 1 0} is also the slip plane in ferrite, it is considered that close spacing between the lath boundaries inhibits general plasticity at stress concentrations and favours initiation of fracture. The differences between the two steels are believed to be due to their transformation behaviours on cooling where precipitation of vanadium nitride in austenite accelerates ferrite formation and raises the temperature of the phase transformation in V-N steels.
Language eng
DOI 10.1016/j.actamat.2015.05.055
Field of Research 091299 Materials Engineering not elsewhere classified
Socio Economic Objective 970109 Expanding Knowledge in Engineering
HERDC Research category C1 Refereed article in a scholarly journal
Copyright notice ©2015, Elsevier
Persistent URL http://hdl.handle.net/10536/DRO/DU:30074773

Document type: Journal Article
Collections: Institute for Frontier Materials
GTP Research
Connect to link resolver
 
Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved.

Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 35 times in TR Web of Science
Scopus Citation Count Cited 33 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 332 Abstract Views, 2 File Downloads  -  Detailed Statistics
Created: Thu, 30 Jul 2015, 10:08:53 EST

Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact drosupport@deakin.edu.au.