Final Year Project
Grain Boundary Engineering of Stainless Steels
Analyses
Grain Count
ASTM E112 - 96
SEM Examination
White Light Interferometry
EBSD
Image Processesing
modifying with matlab
using ASTM standard
Literature survey
Grain Boundaries
Coincident Site Lattice (CSL)
depending on misorientation angle - can predict grain boundary structure (wanatabe lecture)
See Dr Mcleans structural materials book.
Low Angle/High Angle GB
Twin Boundaries
High Order Twin Boundaries
Grain Boundary Character Distribution
Special Boundaries - Sigma (fit) </=29
Fit (sigma value)
determines degree of order
Brandon Criteria can theoretically predict GB misorientations
Effect of straining - 5%CW
EBSD - microstructure development with depth from rolling
Surface effects
Report Topics
Introduction
Grain Boundary Engineering
Literature Survey
Corrosion Resistance
Stainless Steels
Grain Characterisation
Experiemental Proceedures
Results and Analysis
Conlcusions
Testing
Corrosion Testing
pH-modified tetrathionate solution (K2S4O6)
Mechanical Properties Testing
Microhardness
Compressive Strength
Health and Safety
Sample Preparation
Sectioning
Heat Treaments
(1) no heat treatment (5% CW only)
(2) 1100C / 5 min.
(3) 1100C / 30 min.
(4) 1100C / 180 min.
(5) 1050C / 30 min.
(6) 1050C / 180 min.
(7) 950C / 180 min.
(8) 950C / 1440 min.
(9) 900C / 1440 min.
(10) 850C / 1440 min.
10% oxalic acid etch
ASTM A262 practice A