Materials.Business Weekly ⚙️
November 3, 2020
Quote of the week: “Engineers, not racers, are the true drivers of success in motor sport”. The Economist, 19.10.2020. -Listen Podcast-
From The Editor's Corner
AN OLD GREEN STEEL - Part II
A half-done solution
According to the previous mention, the behavior of weathering steel (WS) strongly depends on the exposure conditions. That means that in urban and industrial atmospheres, its corrosion resistance is noticeable higher than carbon steel (CS). Then, WS structures exposed to such kinds of atmospheres show good behavior after several decades of use, and lifetime is considerably extended in comparison to CS. Typically five to eight times lower corrosion rates. Of course, there are many options for employment of WS as a recommended material holding the attack from aggressive atmospheres containing urban and industrial pollutants. Applications in such environments, were long life, low maintenance, and brown color is appreciated, in structures as facades, sculptures, chimneys, transmission towers, bridges, masts, and similar, are a good choice, offering a product life higher than 100 years incurring in minimal maintenance costs. A very common application is in freight containers that can be seen moving around the world, in ships, ports, trucks, and factories, withstanding the most aggressive environments and the harshest handling conditions. A very proper material for regions and countries with aggressive environments and economic limitations for maintenance and replacement as the less developed ones.
The world market of WS in 2019 has been estimated at 1.020 million US dollars or c.a. 1.5 million tons. Some of the major global players producing WS are Gerdau, ArcelorMittal, Tata Steel, Nippon Steel Sumitomo Metal, POSCO, ThyssenKrupp, TISCO, Hyundai Steel, Wuhan Iron and Steel, Ma Steel, and Baogang Group. Current projections say that according to the expected demand, the market will be growing at a compound annual growth rate of 8,8 percent in the coming years. According to that, the global market in 2004 could be 1.600 million US dollars and 2.000 million in 2027. Such increase is associated with attractive opportunities in some regional markets, especially developed and developing countries in the Asia Pacific region, and North America (Mexico, USA, and Canada), regions that, with Europe, traditionally lead the WS world market. Curiously, Latin America and Africa only use a fraction of the global WS production.
In agreement with the conclusions of the study done by the Editor, there are limitations for more broad use of WS. In rural, unpolluted atmospheres, there are no significant differences in the behavior between CS and WS. Neither in environments extremely polluted with chlorides, including some industrial atmospheres, and marine situations like offshore or immediately adjacent to the shoreline.
Moreover, conditions for a protective rust formation on the WS are directly associated with a regime of atmospheric exposure. In other words, conditions as permanent immersion, often splashing, scary aeration, and partial coating of the surface are poor environments for the good behavior of WS. Applications on modified atmospheres, buried or submerged structures, gases, and chemicals must be avoided. Even situations as the feet of the structures, points of dirt accumulation, and any option of crevice formation as lap joints and bolted joints must be treated carefully (periodic maintenance) because the rust formation and stability in this areas are usually different from the rust on the free surface of the structure.
Towards a more comprehensive answer
In front of evident limitations using WS, but considering the potential benefits of similar materials, potentially useful in a wider range of conditions, several efforts seeking solving problems, and some interesting possibilities have emerged over the last decades. Some of the answers and proposals developed by several researchers and entities worldwide are mentioned.
Considering aesthetical issues about the initial appearance of the WS surface and the lixiviation phenomena, due to the slow formation (3-5 five years, usually) of a uniform, adherent, and dark brown layer of corrosion products. But also looking for a better and more resistant layer, and to avoid malformations at extremely lower or higher conditions of aggressiveness, there have been developed some procedures of accelerated “weatherability”, included a formula developed by the Editor and collaborators.
The permanent request on materials engineering handling is to obtain a balance on the properties of the material. A compromise between corrosion behavior, mechanical resistance, and manufacturability. With this purpose, almost 20 years ago, a consortium between the Federal Highway Administration of the USA, the American Iron and Steel Institute, and the US Navy produced the so-called High-Performance Steels – HPS. These Steels were with carbon content lower than 0.11 percent, and a little bit increase in Cu, Si, Ni, Cr, and Mo. Therefore, they were obtained new steels with improved weldability, mechanical resistance, and toughness. Also, corrosion resistance in between CS and WS. A relevant option for moderated atmospheric aggressiveness conditions, where longer spans, light structures, fewer joints, and no maintenance are transcendental. Working on the same line of the advanced WS, H. Cano studied the effect of the increase of Cu (0.29% – 1.06%), Cr (0.08% - 0.54%), and Ni (0.12% - 2.92%). According to her conclusions, no substantial differences were observed in the resistance to atmospheric corrosion by increasing the Cu or Cr content. However, by increasing the Ni content, corrosion resistance improved. An explanation of such positive behavior is the fostering of nano-size (less than 15 μm), superparamagnetic goethite. However, the behavior of these steels exposed to severe marine atmospheres was not relevant in comparison to the conventional WS.
Experiments exploring the effect of some other potential alloying elements have been reported in the literature. For instance, studies about the effect of Mo showed that the kinetics of the corrosion process is close to the conventional behavior in WS, although molybdate appears as part of the rust constituents. Also, J.A. Mejia studied the effect of aluminum, silicon, and manganese. The last one showed no significant effects on the corrosion resistance. Besides, Si promoted the formation of high amounts of superparamagnetic goethite, with the corresponding improvement in the corrosion behavior. In the case of Al, it was confirmed the idea about the decrease of goethite size particles with increasing Al substitution, and a final positive effect, too. Better behavior of these new WS with Si and Al controlled contents, but not in front of very aggressive marine atmospheres.
Nishimura researched the effect of the same two alloying elements, Si and Al, and found an excellent corrosion resistance in comparison with CS. Characterization of the rust showed that both elements were concentrated in the inner sublayer, contributing to the lower size of the rust particle constituents and the final better behavior.
Without any doubt, challenges like highly aggressive marine atmospheres are hard to be attended. Recent endeavors about this subject are part of a new research line, including researchers as Morcillo, from the National Spanish Metallurgical Research Center, where his group is developing holistic research on the subject. Also, some other advances are mentioned below.
Facing this task, a recent study using more recent and sophisticated characterization techniques suggested that a rust transformation is driven by the Mg presence, from the initial constituents (lepidocrocite, maghemite, and magnetite) to magnesioferrite (Mg(Fe)2O4) and iowaite (Mg6Fe2(OH)16Cl2.4H2O), which can attract Cl-, could be responsible for the poor weatherability of WS in severe marine atmospheres. Besides, some other researches have shown that WS enriched with Si, exposed to coastal areas, develop an inner sublayer denser and more compact, conformed by a matrix of coarser akaganeite, and narrow bands of goethite and nanometric SiO2, with a consequent positive role on the better behavior of the WS.
The Nippon Steel offers in the market a product, the NAW TENTM, which is a Fe – Ni 3% - Cu 0.4% - Ca (20 ppm), able to support severe marine environments, according to the company. In this advanced WS, there are implemented some of the recent knowledge about WS. The positive effect of the increase of Ni content, and the importance of maintaining passivation by the stabilization of the basic constituents against the effect by chlorides. Consequently, an alkalinization by Ca and avoiding the presence of Cr are implemented.
The road began a century ago. There is still a lot ahead. The advantages of WS are huge, and they have been projected to severe marine environments, too. But it is necessary to consolidate them. Picking up the ideas by Morcillo in the Eurocorr2019 congress, there is a list of subjects to evaluate in deep. To decrease the size of the particle constituents, to avoid the akaganeite formation, and to block the Cl- migration to the interphase rust/substrate.
There are many reasons to prove that the attention on the inner sublayer is responsible for the good behavior of WS. Modifications of this sublayer with the alloying elements from the substrate, or looking for barriers against chlorides from the environment, are proving attractive. Much simpler interventions such as chemical pre-treatments are useful, too. Nonetheless, suggestions like a physical intervention, mechanically removing the outer sublayer, are interesting because of the potential effect on the wet-and-dry cycle and, eventually, an incidence of the colloidal phases and the resulting lower size of the particle constituents.
Furthermore, there are developments on new alloying elements, more protective layers, and easier and cheaper manufacturability. There are also other huge challenges in front of a broader application of self-protective steels on non- atmospheric conditions. One of the approaches in this sense had been reported by J.K. Singh and D.D.N. Singh -Source- when they compared the rust formation between a CS and low alloy steel in simulated concrete and found that the second one had a better behavior. Innovations regarding rebar options are very valuable. In the same way, it is important to search for WS useful for immersion, chemical, and buried environments.
What’s more, corrosion-resistant materials development cannot continue to be subject to waits of decades of study in expositions to real atmospheres. It is necessary to arrange reliable simulation and modeling procedures into the laboratory and to open the possibility of many new good materials, cheaper and quicker.
The world is complex, rust is complex, their understanding asks for complex approaches, too, beyond empirical or scientific simplified ones. It is the time for a materials revolution supported on the emerging technologies of the Fourth Industrial Revolution: artificial intelligence, machine learning, nanotechnology, and so on, sweeping the periodic table and the corrosion science and engineering repositories, looking for all the infinity options of alloying, and the promising solutions to overcome the current technological barriers of WS.
With such kind of tools on hands, along the last decade emerged a research line about new engineering materials, the so-called Multicomponent High Entropy - MHE - materials. In the same way, since 2015, High Entropy Oxides – HEO, have been studied. It is possible to think about this route as an opportunity for the development of the WS that we are needing. It is a very complementary procedure to the proposal by the Editor, towards the establishment of a novel reverse methodology of materials development, included anticorrosive steels, producing the material according to the formerly designed expected rust, through and easier, rational, and cheaper path. Better, cheaper, and less limited WS is the purpose. Remember: Protection of materials and equipment is good business!
Prof. Carlos Arroyave, Ph.D. Editor.
Materials Biz News
A great anniversary
Century 20th was the time of polymers. Starting from the simple bakelite, and closing with a huge variety of new materials, a lot of them very useful in anticorrosive measurements: bulk materials, coatings, paints, inhibitors, adhesives, composites, and so on. A milestone on the starting point was the paper Über Polymerisation (About Polymerization) by Hermann Staudinger, in 1920, at the journal Berichte der deutschen chemischen Gesellschaft. Definitively, As Neil Armstrong said, "That's one small step for man. One giant leap for mankind." Celebrating such an anniversary on the development of engineering materials, the journal “Progress in Polymer Science” has launched a special free access package of reviews about current developments, trends, and perspectives in macromolecular chemistry. -Read More-
Ukrainian International Airlines – UIA, MAUtechnic, an aviation maintenance company in Ukraine, and Luftronix have decided to join for the development of a project about the use of drones for high-precision scanning of aircraft and data analytics as an improved and faster method of automated inspection, monitoring, maintenance, and quality assurance of assets. -Watch Video-
Preventing corrosion at the microscopic level
Nancy Sottos, head of the Department of Materials Science and Engineering at the University of Illinois at Urbana-Champaign, and her collaborators, recently published a paper concerning the invention of pH-responsive monodisperse microcapsules, According to authors, they developed a methodology for the generation of monodisperse, stimuli-responsive microcapsules or shell required for precise delivery of chemicals. One of the proved applications included the use of shells sensitive to pH changes and, then, breakable, releasing any anticorrosive agent (pH controller or so on) on the specific microscopic point. -Read More-
On the shoulders of dwarves
In the current Industrial Revolution, where most of the technologies that converge are close to electronics, corrosion of electro-electronics is a growing matter of concern. A powerful reason for the global giant Henkel Adhesive Technologies to put venture capital into “actnano”, an advanced materials start-up providing a coatings technology for the protection of printed circuit boards (Advanced nanoGuard™), because of the comprehensive waterproofing and environmental resistant properties achieved. -Read More-
Invitation to be part of a great tradition on Corrosion studies - Manchester, UK
The Department of Materials of the Faculty of Science and Engineering of the University of Manchester is seeking for research associated, to be part of the team in charge of a project entitled “LightForm Understanding Crack Initiation on Aluminium Alloys”. This is a collaboration with some other UK universities and 20 industrial partners. The required candidate must be an expert on metallurgy and corrosion, interested in the understanding of the crack initiation on Al alloys under simultaneous mechanical and chemical loads. Procedures to be developed include SEM-TEM characterization and electrochemical tests. Also, the tutoring of Ph.D. students is part of the included duties.
Plating process manager - Tijuana, Mexico
EATON, a global power management company, is looking for a Special Process Engineer for its branch in Tijuana, Mexico. Basic qualification includes a bachelor’s degree in chemical or materials engineering, with at least five years of manufacturing experience in processes like electroplating, chemical mixing, and pumping, and wastewater treatment. English fluency, strong communication skills, and proficiency in Microsoft Office are required, too. Furthermore, experience in management and leadership are some of the additional preferred qualifications.
Senior energy specialist - Manila, Philippines
The Asian Development Bank (ADB), Manila, Philippines, is looking for candidates to fill the above-mentioned vacancy. Expected qualification includes a Master's degree in Engineering, Finance, Economics, Public Policy, or other related specialized fields. Also, 10 or more years of professional experience in the design and management of projects in the energy sector, and excellent English skills are required. Other wanted soft skills include client orientation, leadership, and coaching capabilities.
The World Academy of Sciences for the Advancement of Science in Developing Countries - TWAS, in a partnership with UNESCO and almost 300 research centers, calls for applications for grants supporting visits by researchers with a Ph.D. degree or equivalent, from developing countries to centers in the South, for collaborative work. Selected researchers will be sponsored for a lapse of three years, including up to two visits to the selected center for 2-3 months each time. Centers dealing with materials and corrosion science and engineering supporting the program include an important group of Argentinian institutions like:
-CIDEPINT - Research Centre on Paint Technology
-INCAPE - Institute of Catalysis and Petro Chemistry Research
-INENCO - Research Institute on Non-Conventional Energy
-INTEMA - Research Institute on Science and Materials Technology
-INIFTA - Research Institute for Theoretical and Applied Physical-Chemistry
In other countries, there are also centers related to materials protection, including:
-Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific, Research, Jakkur Campus, Jakkur P.O. Bangalore 560 064, India
-International Water Management Institute (IWMI), Sub Regional Office for Nile Basin & Eastern Africa, P. O. Box 5689, Addis Ababa, Ethiopia
-Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China
-Institute of Process Engineering, Chinese Academy of Sciences (IPE, CAS), #1 Beiertiao, Zhongguancun, Haidian District, Beijing, China
-Indian Institute of Technology (IIT), P.O. IIT Kanpur, India
-International Centre for Science, High Technology and Environmental Sciences (ICST), End of Haftbagh Alavi Highway, 7631133131 Kerman, Iran
-Shanghai Institute of Microsystem & Information Technology, (formerly Shanghai Institute of Metallurgy) Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China
Networking & Knowledge Exchange
Ensuring better performance - Virtual
NACE International offers a 90-minute self-paced course on “Ethics for the Corrosion Professional”. The content includes topics such as the commitment of corrosion professionals to people, assets, and the environment. Also, a discussion on the NACE International Code of Ethics and case studies are reviewed. Finally, the strengthening of the criteria framework for ethical decision making will be achieved.
Managing MIC - Virtual
The Energy Institute is organizing a course on “Microbiologically Influenced Corrosion - Corrosion Management & Failure Analysis” to be held on November 9th -10th 2020. According to the announcement, this course is oriented to professionals involved with corrosion management activities, both in the lab as on the field (onshore and offshore). Subjects include the diagnosis, prevention, and treatment of MIC in the upstream O&G, marine, and water sectors.
Learning from war and peace - Virtual
As part of a webinars series, the ASM International – Ontario Chapter is organizing a presentation on “US Army Research and Nano-Galvanitic Steel”, to be offered by Shawn Walsh of the U.S. Army CCDC Army Research Laboratory. This speech is scheduled for Tuesday, November 10th, 2020, at 14:00 (EST). In particular, a presentation of the discovery of a nanogalvanic aluminum alloy will be emphasized, as an example of the importance of new materials development on the coming army requirements.
Improving skills on anticorrosive coatings - Virtual
As part of its training activities, NACE Gateway India is organizing a course on “Advanced Program on Coating Technology and Quality Control”. To be held on the 6th and 7th November 2020, from 9.00 to 14.00. Issues to be considered include fundamentals, surface preparation, coating application, pipeline protection, standards, QC, safety & hazards, coating failure & selection. Invited people include contractors, owners, and professionals involved with anticorrosive protection by paints and coatings.
Fostering innovation by protecting knowledge - Virtual
The United States Patent and Trademark Office announced a training webinar on the Patent Center Beta, a new tool for electronic filing and management of patent applications. Two coming sessions are scheduled on 5th and 19th November 2020, 13:00 to 14:00 (EST). Improvements and characteristics of the new procedure will be presented.