Backe L.,Dalarna University |
The effect of solute drag on recovery and recrystallization during hot deformation of Nb microalloyed steels has been modeled using a newly developed microstructure model. The model is based on dislocation theory and the calculated dislocation density determines the driving force for recrystallization. Subgrains act as nuclei for recrystallization and have to reach a critical size and configuration in order for recrystallization to start. In the model, the solute drag effect of Nb in solution is described. Nb retards both dislocation and grain boundary movement giving retardation in both recovery and recrystallization. Calculations were compared to experimental results from axisymmetric compression tests combined with stress relaxation. In order to model the effect of solute drag, the experiments were carried out at temperatures where precipitation of Nb(C, N) should not occur. The calculated flow stresses for the compression tests show good fit with experimental data. Also, the calculated results of the relaxation tests show good agreement with experimental data. © 2010 ISIJ. Source
Agency: Cordis | Branch: H2020 | Program: MSCA-ITN-EID | Phase: MSCA-ITN-2015-EID | Award Amount: 2.11M | Year: 2015
The five partners EFD (Norway), SSAB, Outokumpu, and University of Oulu (Finland), and WIAS (Germany) propose an EID programme on Mathematics and Materials Science for Steel Production and Manufacturing, where eight PhD projects are jointly carried out, providing a unique interdisciplinary and inter-sectorial training opportunity. The research is focussed on three major topics - induction heating, phase transformations in steel alloys, ladle stirring. Two theses concern hardening: one is the hardening of helical and bevel gears by an optimized single or multi-frequency approach and the other is a novel idea about the hardening of the inner surface of pipes. Two of the theses are related to induction heating applications in the production of high-frequency welded pipes and for pre- and post-heating in the thermal cutting of steel plates. Two theses are concerned with phase transformations during steel production and the final two theses are related to secondary metallurgy in the ladle, optimal alloying strategies and an inverse problem related to stirring efficiency. Despite the fact that most theses projects deal with established processes, they are not fully understood nor fully controllable from a quality point of view. Improved and optimized process control requires quantitative mathematical modelling, simulation and optimization of the complex thermal cycles and thermal gradients experienced by the processed material. Such models require an understanding of the behaviour of the materials from a materials science and phase transformations perspective. Tailored industrial on-site trainings, customized courses in physical modelling and testing of steels as well as numerical simulation of induction heating and flow phenomena combined with scientific research in carefully selected topics on the interface of materials science and applied mathematics will provide the early stage researchers with excellent qualifications to pursue a career in academia or industry.
Agency: Cordis | Branch: H2020 | Program: RIA | Phase: LCE-15-2014 | Award Amount: 12.99M | Year: 2015
STEPWISE is a solid sorption technology for CO2 capture from fuel gases in combination with water-gas shift and acid gas removal. The main objectives of the proposed STEPWISE project is to scale up the technology for the CO2 capture from Blast Furnace Gases (BFG) with three overall demonstration goals in comparison to state-of-the-art amine-based technologies: Higher carbon capture rate i.e. lower carbon intensity, 85% reduction Higher energy efficiency i.e. lower energy consumption for capture (SPECCA ), 60% reduction Better economy i.e. lower cost of CO2 avoided, 25% reduction The STEPWISE project will achieve this by the construction and the operation of a pilot test installation at a blast furnace site enabling the technology to reach TRL6 as the next step in the research, development and demonstration trajectory. Hence further reducing the risk of scaling up the technology. The STEPWISE project has the potential to decrease CO2 emissions worldwide by 2.1Gt/yr based on current emission levels. The conservative estimate is that by 2050, a potential cost saving of 750 times the research costs for this project will be realized each year every year, with a much larger potential. The overall objective is to secure jobs in the highly competitive European steel industry, a sector employing 360 thousand skilled people with an annual turnover of 170 billion.
SSAB Steel, Sweden, introduces Docol 1500 MZE electrogalvanized martensitic grade high-strength structural steel for automotive applications. The ultra-high strength steel is appropriate for a range of applications in need of corrosion protection, energy absorption, and low weight. "For many years now, our Docol series of martensitic grades have been contributing to low weight and sustainability without compromising performance," says Arnaud Guerendel, global director for the automotive segment at SSAB. "As knowledge and awareness spread, more designers see the possibilities of using our material. We have continual requests by different companies for our strongest and highest strength steels." Docol 1500 MZE is a cold-rolled, electrogalvanized advanced high-strength steel developed for applications in cars with stringent requirements for low weight and high energy absorption. The steel is well suited for roll forming. The minimum tensile strength is 1500 N/mm² and the high strength is achieved in the manufacturing process, which uses a special heat treatment together with an extremely high cooling rate. "When we develop new steel grades, we always have our customers' business in focus whether we're developing new products or adjusting the properties of our steel grades to fit specific applications," says José Puente, global product manager for the automotive segment at SSAB. "This is the strong driving force behind our continuous research and development efforts."
SSAB, Sweden, has agreed to deliver a total of 25,000 metric tons of metal-coated high-strength steel to the Spanish company CIE Egana to build support arms for parabolic reflectors in thermosolar plants. The high-strength steel has a thick Galfan (95%Zn-5%Al) coating to prevent corrosion and extend product lifetime for power plants that can produce electricity for decades. Metal-coated high-strength steels enable the manufacture of stronger and lighter support structures. Deliveries began in December 2015 and will continue until October 2016. The Noor II thermosolar plant to be built in Morocco will have an output of 200 megawatts and the Kathu plant to be built in South Africa will have an output of 100 megawatts. SSAB delivered the coated high-strength steels to the Noor I thermosolar plant built earlier in Morocco. When the Noor II plant is completed, the two plants together will have a combined output of 360 MW. The Kathu thermosolar plant in South Africa will provide electricity for about 80,000 homes.