Specimens from the pipe were examined both macroscopically and microscopically. Inductively Coupled Plasma-Atomic Energy Spectroscopy (ICP-AES) technique was used to measure the chemical composition of the pipe material.
The carbon content was determined by analyzing the products of burning a specimen using gas chromatography. Metallographic specimens as well as samples of corrosion products were prepared from the pipe for detailed characterization by optical metallography, x-ray diffraction (Cu-Ka radiation) as well as various electron-optical techniques including scanning electron
microscopy (SEM: JEOL 5800LV) combined with energy dispersive x-ray spectroscopy, and transmission electron microscopy (TEM: JEOL 2000EX).
Specimens were examined both in the as-received, polished, and etched conditions.
Etching was carried out in oxalic acid.
Thin foils for transmission electron microscopy were prepared by the jet H.M. Tawancy and Luai.M. Al-Hadhrami, Centre for Engineering Research and Centre of Research Excellence in Corrosion, Research Institute, King Fahd University of Petroleum & Minerals, P.O. Box 1639, Dhahran 31261, Saudi Arabia.
Contact e-mail: tawancy@ kfupm.edu.sa.
JMEPEG (2012) 21:1757–1762 ASM International
DOI: 10.1007/s11665-011-0076-0 1059-9495/$19.00
Journal of Materials Engineering and Performance Volume 21(8) August 2012—1757
polishing technique in a solution consisting of one part nitric
acid and three parts methanol by volume.
All foils were examined at an accelerating voltage of 200 kV.
Microhardness measurement using Vickers hardness tester (200 g load) was used to evaluate the mechanical strength.
At least five measurements were made in regions near the perforation and far from it.