File(s) under permanent embargo
Reason: This item is currently closed access.
The influence of weld thermal cycle simulations on the microstructure of VM12-SHC steel
conference contribution
posted on 2019-07-18, 10:44 authored by Robert Byrne, Mark JepsonMark Jepson, Rachel ThomsonRachel Thomson, J. Shingledecker, John A. SiefertFor VM12-SHC 11-12 wt. % Cr steel, there have been no systematic investigations to define the
regions or characterise the microstructures within the heat-affected zone (HAZ) of weldments. In
similar steels, these regions relate to the Ac1 and Ac3 transformation temperatures and can affect
weldment performance. In this study, controlled thermal cycles were applied to VM12-SHC parent
metal using a dilatometer and the Ac1 and Ac3 temperatures were measured for various heating
rates. The Ae1 and Ae3 temperatures were also calculated by thermodynamic equilibrium modeling.
Through dilatometry, thermal cycles were then applied to simulate the microstructures of the
classically defined HAZ regions. The microstructural properties of each simulated material were
investigated using advanced electron microscopy techniques and micro-hardness testing. It was
found that the simulated HAZ regions could be classified as; (1) the completely transformed (CT)
region, with complete dissolution of pre-existing precipitates and complete reaustenitisation; (2)
the partially transformed (PT) region, exhibiting co-existing original martensite with nucleating
austenite microstructures with partial dissolution of precipitates; and (3) the over tempered (OT)
region, with no phase transformation but precipitate coarsening and decreased hardness.
Funding
We thank the Engineering and Physical Sciences Research Council (EPSRC) Centre for Doctoral Training in Carbon Capture and Storage and Cleaner Fossil Energy (grant number: EP/L016362/1) for their support of the project.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Materials
Published in
Joint EPRI-123HiMAT International Conference on Advances in High Temperature MaterialsCitation
BYRNE, R.G. ... et al., 2019. The influence of weld thermal cycle simulations on the microstructure of VM12-SHC steel. Presented at the Joint EPRI-123HiMAT International Conference on Advances in High Temperature Materials, Nagasaki, Japan, 21-25th October.Publisher
© Electric Power Research Institute (EPRI)Version
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Acceptance date
2019-07-16Publication date
2019Notes
This paper is in closed access.Publisher version
Language
- en