TitleOptimization of Sigma Phase Precipitates with Respect to the Functional Properties of Duplex Cast Steel
Journal titleArchives of Foundry Engineering
KeywordsInnovative Foundry Materials and Technologies ; duplex cast steel ; Sigma Phase ; Heat Treatment ; Shape Factor
Divisions of PASNauki Techniczne
Archives of Foundry Engineering continues the publishing activity started by Foundry Commission of the Polish Academy of Sciences (PAN) in Katowice in 1978. The initiator of it was the first Chairman Professor Dr Eng. Wacław Sakwa – Corresponding Member of PAN, Honorary Doctor of Czestochowa University of Technology and Silesian University of Technology. This periodical first name was „Solidification of Metals and Alloys” , and made possible to publish the results of works achieved in the field of the Basic Problems Research Cooperation. The subject of publications was related to the title of the periodical and concerned widely understand problems of metals and alloys crystallization in a casting mold. In 1978-2000 the 44 issues have been published. Since 2001 the Foundry Commission has had patronage of the annually published “Archives of Foundry” and since 2007 quarterly published “Archives of Foundry Engineering”. Thematic scope includes scientific issues of foundry industry:
- Theoretical Aspects of Casting Processes,
- Innovative Foundry Technologies and Materials,
- Foundry Processes Computer Aiding,
- Mechanization, Automation and Robotics in Foundry,
- Transport Systems in Foundry,
- Castings Quality Management,
- Environmental Protection.
The paper presents the results of examination concerning optimization of the σ phase precipitates with respect to the functional properties of ferritic-austenitic cast steel. The examined material comprised two grades of corrosion-resistant cast steel, namely GX2CrNiMoN25-6-3 and GX2CrNiMoCuN25-6-3-3, used for example in elements of systems of wet flue gas desulphurisation in power industry. The operating conditions in media heated up to 70°C and containing Cl- and SO4 ions and solid particles produce high erosive and corrosive wear. The work proposes an application of the σ phase as a component of precipitation strengthening mechanism in order to increase the functional properties of the material. Morphology and quantities of σ phase precipitates were determined, as well as its influence on the erosion and corrosion wear resistance. It was shown that annealing at 800°C or 900°C significantly improves tribological properties as compared with the supersaturated state, and the best erosion and corrosion wear resistance achieved due to the ferrite decomposition δ → γ’ + σ was exhibited in the case of annealing at the temperature of 800°C for 3 hours.
PublisherThe Katowice Branch of the Polish Academy of Sciences
TypeArtykuły / Articles
ReferencesJohansson K. (2007), 25 years with duplex. From Tammeliten to Gjoea, null. ; Martins M. (2009), Microstructural characteristics and corrosion behavior of a super duplex stainless steels casting, Materials Characterizations, 60, 2, 150, doi.org/10.1016/j.matchar.2008.12.010 ; Cassgne T. (2007), Experience with duplex stainless steels in oil and gas prodution, null. ; Stradomski Z. (2010), Microstructure in the problems of abrasion-resting cast steel wear. ; Stradomski Z. (2011), Ferritic-austenitic cast steel-selected problems, Archives of Foundry Engineering, 11, 3, 47. ; Topolska S. (2009), Effect of microstructure on impact toughness of duplex and superduplex stainless steels, Journal of Achievements in Materials and Manufacturing Engineering, 36/2, 142. ; Brodziak A. (2010), Assessment the possibility of enhancing the tribological properties of the ferritic-austenitic cast steel, Archives of Foundry Engineering, 10, 1, 287.