Microalloyed steels are widely used in oil and gas pipelines. They are a class of high strength, low carbon steels containing small additions (in amounts less than 0.1 wt%) of Nb, Ti and/or V. The steels may contain other alloying elements, such as Mo, in amounts exceeding 0.1wt%. Precipitation in these steels can be controlled through thermomechanical controlled processing, leading to precipitates with sizes ranging from several microns to a few nanometers. The larger precipitates are essentially TiN, with partial substitution of Nb for Ti, while the smaller precipitates are based on NbC, with Ti, Mo and V partially substituting for Nb and N partially substituting for C. Microalloyed steels have good strength, good toughness and excellent weldability, which are attributed in part to the presence of the nano-sized carbides and carbonitrides. Because of their fine sizes and low volume fraction, conventional microscopic methods are not satisfactory for quantifying these precipitates. Matrix dissolution is a promising alternative to extract the precipitates for quantification. Relatively large volumes of material can be analyzed, so that statistically significant quantities of precipitates of different sizes are collected. In this paper, matrix dissolution techniques have been developed to extract the precipitates from a series of microalloyed steels. Transmission electron microscopy (TEM) and x-ray diffraction (XRD) are combined to analyze the chemical speciation of these precipitates. Rietveld refinement of the XRD pattern is used to fully quantify the relative amounts of the precipitates. The size distribution of the nano-sized precipitates is quantified using dark field imaging in the TEM.
Skip Nav Destination
2008 7th International Pipeline Conference
September 29–October 3, 2008
Calgary, Alberta, Canada
Conference Sponsors:
- International Petroleum Technology Institute and the Pipeline Division
ISBN:
978-0-7918-4859-3
PROCEEDINGS PAPER
Extraction and Characterization of Nano Precipitates in Microalloyed Steels
J. Lu,
J. Lu
University of Alberta, Edmonton, Alberta, Canada
Search for other works by this author on:
D. G. Ivey,
D. G. Ivey
University of Alberta, Edmonton, Alberta, Canada
Search for other works by this author on:
H. Henein,
H. Henein
University of Alberta, Edmonton, Alberta, Canada
Search for other works by this author on:
J. B. Wiskel,
J. B. Wiskel
University of Alberta, Edmonton, Alberta, Canada
Search for other works by this author on:
O. Omotoso
O. Omotoso
CANMET Energy Technology Centre - Devon, Devon, Alberta, Canada
Search for other works by this author on:
J. Lu
University of Alberta, Edmonton, Alberta, Canada
D. G. Ivey
University of Alberta, Edmonton, Alberta, Canada
H. Henein
University of Alberta, Edmonton, Alberta, Canada
J. B. Wiskel
University of Alberta, Edmonton, Alberta, Canada
O. Omotoso
CANMET Energy Technology Centre - Devon, Devon, Alberta, Canada
Paper No:
IPC2008-64135, pp. 85-94; 10 pages
Published Online:
June 29, 2009
Citation
Lu, J, Ivey, DG, Henein, H, Wiskel, JB, & Omotoso, O. "Extraction and Characterization of Nano Precipitates in Microalloyed Steels." Proceedings of the 2008 7th International Pipeline Conference. 2008 7th International Pipeline Conference, Volume 3. Calgary, Alberta, Canada. September 29–October 3, 2008. pp. 85-94. ASME. https://doi.org/10.1115/IPC2008-64135
Download citation file:
10
Views
0
Citations
Related Proceedings Papers
Related Articles
A Comparison Between Measured and Modeled Residual Stresses in a Circumferentially Butt-Welded P91 Steel Pipe
J. Pressure Vessel Technol (February,2010)
Decomposition of Thermal and Mechanical Effects on Microstructure and Hardness of Hard Turned Surfaces
J. Manuf. Sci. Eng (May,2004)
Transformation Textures in Unstable Austenitic Steel
J. Eng. Mater. Technol (January,2003)
Related Chapters
Surface Analysis and Tools
Tribology of Mechanical Systems: A Guide to Present and Future Technologies
New Implications for Geo-Mechanism of the Sandstone Diagenesis, from Diagenetic Heterogeneity of Lenticular Sandbody in Shahejie Formation, Bohai Bay Basin
International Conference on Electronics, Information and Communication Engineering (EICE 2012)
Insulating Properties of W-Doped Ga2O3 Films Grown on Si Substrate for Low-K Applications
International Conference on Advanced Computer Theory and Engineering, 4th (ICACTE 2011)