Conveners
Duplex stainless steels: Duplex stainless steels I
- Claes OLSSON (Sandvik Mateirals Technology)
- Andreas Keplinger (voestalpine BÖHLER Edelstahl GmbH & Co KG)
Duplex stainless steels: Duplex stainless steels II
- Stefan Ulrich (deutsch)
- Anthony Nicholas Grundy (Thermo-Calc AB)
Duplex stainless steels: Duplex stainless steels III
- Marcel Somers (Technical University of Denmark)
- irene calliari (Univerity of Padova)
Duplex stainless steels: Duplex stainless steels IV
- Claudio Gennari
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Ms Andrea Putz (Institute of Materials Sciene, Joining and Forming, TU Graz, Kopernikusgasse 24/I, 8010 Graz, Austria)01/10/2019, 09:00Duplex stainless steelsOral PresentationDuplex stainless steels consist of almost equal amounts of austenite and ferrite due to their chemical composition and thermal history. The balanced microstructure of austenitic islands embedded in the ferritic matrix is achieved by solution annealing followed by water quenching to room temperature. Thick-walled plates have locally fairly wide austenite spacing as compared to thin sheets. This...Go to contribution page
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RODRIGO MAGNABOSCO (FEI University)01/10/2019, 09:20Duplex stainless steelsOral PresentationPerformance of stainless steels (SS) is a direct function of the microstructure, and phase quantification is an important experimental procedure for microstructural characterization. X-ray diffratometry (XRD) is widely used in phase identification of SS, and analysis of the diffracted intensity peaks of the phases allows the determination of their volume fractions. X-ray diffraction...Go to contribution page
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RODRIGO MAGNABOSCO (FEI University)01/10/2019, 09:40Duplex stainless steelsOral PresentationDuplex stainless steels (DSS) are composed of ferrite and austenite in approximately equal amounts combining properties of both phases. Pitting Resistance Equivalent Number “PREN” is a theoretical way to measure pitting corrosion resistance of steels based on the composition of the material. Nevertheless, in a duplex structure the alloy elements may be partitioned between the phases...Go to contribution page
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Stefan Ulrich (Guenter Koehler Institute of Joining and Material Testing)01/10/2019, 10:00Duplex stainless steelsOral PresentationThe laser welding process is characterized by a high heating and cooling rate as well as large temperature gradients. The dwell time between heating and cooling is minimal. Especially when welding thin-walled (d ≤ 1 mm) duplex stainless steels, the austenite content in the joint zone is reduced. However, a balanced phase ratio of ferrite and austenite combines high levels of mechanical...Go to contribution page
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James Oliver (Outokumpu Stainless AB)01/10/2019, 10:50Duplex stainless steelsOral PresentationThe new duplex steel FDX 27 should be implemented into relevant standards. As for other duplex stainless steel grades, correct solution annealing is one of the most critical aspects for achieving good material properties and a relevant standard in this respect is of great importance for delivery of material with good quality. Testing of high alloyed duplex stainless steels is covered in ASTM...Go to contribution page
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Claes OLSSON (Sandvik Materials Technology)01/10/2019, 11:10Duplex stainless steelsOral PresentationImpact toughness is a key parameter for many applications of duplex stainless steels. Conventional parameters that are known to have a strong influance on macro properties include phase fraction and austenite spacing. In this paper, we illustrate how image analysis can be used to extract new parameters and demonstrate that these parameters have an even stronger correlation to macro properties...Go to contribution page
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Andreas Keplinger (voestalpine BÖHLER Edelstahl GmbH & Co KG)01/10/2019, 11:30Duplex stainless steelsOral PresentationDuplex stainless steels combine excellent mechanical properties and corrosion resistance, while simultaneously maintaining lower alloying costs than comparable types of stainless steels. Consequently, they are in frequent use in various types of highly demanding applications, like Oil&Gas, chemical processing and desalination plants. An increasing amount of alloying elements, as used in Super...Go to contribution page
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Benjamin Wittig (Otto-von-Guericke-University Magdeburg)01/10/2019, 11:50Duplex stainless steelsOral Presentation**Abstract** For the successful welding of high-alloy and corrosion-resistant duplex stainless steels, a number of welding recommendations have been established over the past decades which guarantee the required material-specific properties of the welds. These include, inter alia, compliance with defined heat input and interpass temperatures as well as the use of filler metals over-alloyed...Go to contribution page
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Sonja Felber (Institute for Building Construction and Technology, Vienna University of Technology)01/10/2019, 12:10Duplex stainless steelsOral PresentationABSTRACT Today the duplex-steel 1.4462 is often used for flow-lines and a lot of money is spent worldwide into finding the right joining process for the circumferential welds of these pipes. A worldwide central collection of welding variables and their efficient processing could result in a prediction of the mechanical properties and fracture mechanical values out of the data of the...Go to contribution page
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Julia Contreras Fortes (ACERINOX EUROPA, SAU)01/10/2019, 14:00Duplex stainless steelsOral PresentationThe duplex stainless steel family is widely used in many structural applications due to its high mechanical resistance with a yield stress of about two times the austenitic’s and its outstanding corrosion resistance. An example of this is the grade EN-1.4462 with a yield stress value usually higher than 450 N/mm2 and the tensile strength value between 650 and 880 N/mm2. Another important...Go to contribution page
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Anthony Nicholas Grundy (Thermo-Calc Software, Citizen Space Zurich, Heinrichstrasse 267, 8005 Zürich, Switzerland)01/10/2019, 14:20Duplex stainless steelsOral PresentationThe prediction of alloying effects on phase equilibria and transformations in advanced stainless steels and in particular duplex stainless steels is complicated. This makes computational thermodynamics and kinetics an indispensable tool for the materials industry. It has been successfully deployed in the alloy development of steels for decades and continuously developed towards use in more and...Go to contribution page
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Johan Pilhagen (Outokumpu Stainless, R&D Avesta, Sweden)01/10/2019, 14:40Duplex stainless steelsOral Presentation**Abstract:** In the design of steel structure, the avoidance of brittle fracture is of great importance as e.g. steel bridges are exposed to low temperatures and fatigue loads. In the supplementary rules for the design of stainless steel structures in the European standard EN 1993-1-4 as part of the Eurocode 3-familiy, toughness requirements for stainless steels are given. However, the...Go to contribution page
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Claudio Gennari (University of Padova)01/10/2019, 15:00Duplex stainless steelsOral PresentationIt is well known that increasing the temperature soften the materials and increase its formability. This could be done in many ways, one of which is by joule heating. In the late fifties, an enhancement of formability for certain alloys, when heated by electrical current compared to traditional heating method, has been observed . This led the researcher to investigate the effect of electrical...Go to contribution page
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Vahid A Hosseini (Department of Engineering Science, University West)01/10/2019, 15:20Duplex stainless steelsOral PresentationSuper duplex stainless steels (SDSS) combine superior mechanical properties and high corrosion resistance, which makes them an attractive choice for demanding applications. The welding of SDSS, however, is more challenging than for standard and lean duplex stainless steels as the desired balanced ferrite fraction sometimes is conflicting with the more rapid formation of deleterious phases in...Go to contribution page
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Sten Wessman (Swerim AB)01/10/2019, 16:10Duplex stainless steelsOral PresentationStainless steels are high-alloyed, usually with multiple components and often also dual matrix phases, as for duplex stainless steels. This makes predictions and calculations of alloying effects on equilibria and phase transformations a challenge. Computational thermodynamics has emerged as an indispensable tool for calculations within these complex systems on predictions of equilibria and...Go to contribution page
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Borut Žužek (Institute of metals and technology)01/10/2019, 16:30Duplex stainless steelsOral PresentationSAF 2205 duplex stainless steel has good corrosion resistance, mechanical strength, weldability at relatively low price. But it is susceptible to sigma phase precipitation. The sigma phase is a hard and brittle intermetallic phase that occurs in the Fe.-Cr system. The temperature range from 600 to 950 °C is critical for the sigma phase precipitation. The effects of time and temperature on the...Go to contribution page