Edmonton—A research team from the Department of Chemical and Materials Engineering was recently presented with niobium medals for winning the Charles Hatchett Award at the Institute of Materials, Minerals and Mining.
The award, for the best research paper on the science and technology of niobium and its alloys, was presented to: Junfang Lu, Enbridge Pipelines Inc. a University of Alberta alumnus; Oladipo Omotoso, Suncor Energy Inc.; J. Barry Wiskel, U of A Faculty Service Officer; Douglas Ivey, U of A professor; and Hani Henei, U of A professor. Their paper, entitled Strengthening Mechanisms and Their Relative Contributions to the Yield Strength of Microalloyed Steels, was published in the journal Metallurgical and Materials Transactions in 2012.
The Charles Hatchett Award is an international prize, awarded annually for published work on the science and technology of niobium. The prize is in two parts; a specially designed and minted medal of pure niobium and funding to visit the industrial facilities of the world’s largest producer of niobium, the Companhia de Metalurgia e Mineração (CBMM) in Brazil.
This year’s winning paper looks at using matrix dissolution to analyze microalloyed steels for strengthening mechanisms. Microalloyed steels are used widely in oil and gas pipelines and precipitation in these steels can be controlled through thermomechanical-controlled processing. This leads to precipitates with sizes that range from several microns to a few nanometers. Conventional microscopic methods are not satisfactory for quantifying these precipitates because of their ﬁne sizes, wide particle size distribution, and low volume fractions.
The paper shows that matrix dissolution is a promising alternative to extract the precipitates for quantiﬁcation as relatively large volumes of material can be analyzed so that statistically signiﬁcant quantities of precipitates of diﬀerent sizes can be collected. The researchers looked at microstructure features of a series of microalloyed steels (X70, X80, and X100) as well as a Grade 100 steel which were characterized using optical microscopy (OM) and scanning electron microscopy (SEM), and a chemical dissolution technique to extract the precipitates from the steels. In order to understand fully the strengthening mechanisms for these steels, individual strengthening contributions from grain size eﬀects, solid-solution strengthening, and precipitation strengthening were quantiﬁed.
“This study was a part of our collaborative research with EVRAZ, Inc NA (formerly IPSCO), said Hani Henein, “the collaboration has grown over the subsequent 15 years. One of its primary objectives is building sustainable relationships and connecting people and skills. The collaboration has been led by Laurie Collins, Director of R&D at EVRAZ, by myself as Principal Investigator, and Doug Ivey, Jingli Luo and Barry Wiskel, from the Department of Chemical and Materials Engineering at the U of A,” he explained.
“Working together, we have involved a total of eight faculty members in this research and have trained nearly 20 highly-qualified personnel and educated over 200 undergraduate students in the manufacturing of pipe,” Henein said.
On the possible future applications of this research, Henein said it is always hard to predict how a contribution is used, but added that “there are already signs” that several labs are adopting the team’s technique as a method of analyzing steels.