Microstructural Evolutions and its Influence on Properties of Super-Duplex Stainless Steel

2010 ◽  
Vol 97-101 ◽  
pp. 656-659 ◽  
Author(s):  
Ying Han ◽  
De Ning Zou ◽  
Hong Hong Yao ◽  
Wei Zhang ◽  
Jun Hui Yu
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Energy Spectrum ◽  
Duplex Stainless Steel ◽  
Aging Time ◽  
Aging Temperature ◽  
Super Duplex Stainless Steel ◽  
Σ Phase ◽  
Mechanical Properties And Corrosion

Color-optical microscopy, energy spectrum analysis, hardness measuring, tensile and corrosion testing were conducted to investigate characteristics of microstructure, mechanical properties and corrosion resistance of S32750 super-duplex stainless steel aged at 850～920°C. The results indicate that with the increase of aging temperature and aging time the content of σ phase increases, while the ferrite content decreases. The forming and growing of σ phase obtained during aging causes an increase in hardness and a reduction in ductility of the aged steel. Moreover, increasing aging time the corrosion resistance reduces, owing to a new formed austenite occurs.

Influence of Sigma Phase Precipitation on Pitting Corrosion of 2507 Super-Duplex Stainless Steel

2010 ◽  
Vol 658 ◽  
pp. 380-383 ◽  
Author(s):  
Ying Han ◽  
De Ning Zou ◽  
Wei Zhang ◽  
Jun Hui Yu ◽  
Yuan Yuan Qiao
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Ambient Temperature ◽  
Duplex Stainless Steel ◽  
Pitting Corrosion ◽  
Super Duplex Stainless Steel ◽  
Phase Precipitation ◽  
Pitting Potential ◽  
Σ Phase ◽  
Pitting Corrosion Resistance

Specimens of 2507 super-duplex stainless steel aging at 850°C for 5 min, 15 min and 60 min were investigated to evaluate the pitting corrosion resistance in 3.5% NaCl solution at 30°C and 50°C. The results are correlated with the microstructures obtained with different aging time. The precipitation of σ phase remarkably decreases the pitting corrosion resistance of the steel and the specimen aged for 60 min presents the lowest pitting potential at both 30°C and 50°C. With increasing the ambient temperature from 30°C to 50°C, the pitting potential exhibits a reduction tendency, while this tendency is less obviously in enhancing the ambient temperature than in extending the isothermal aging duration from 5 to 60 min. SEM analysis shows that the surrounding regions of σ phase are the preferable sites for the formation of corrosion pits which grew up subsequently. This may be attributed to the lower content of corrosion resistance elements in these regions formatted with σ phase precipitation.

scholarly journals Effect of Solution Treatment Temperature on Microstructural Evolution, Precipitation Behavior, and Comprehensive Properties in UNS S32750 Super Duplex Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1481
Author(s):  
Junhe Li ◽  
Wei Shen ◽  
Ping Lin ◽  
Fuming Wang ◽  
Zhanbing Yang
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Solution Treatment ◽  
Element Distribution ◽  
Treatment Temperature ◽  
Solution Treatment Temperature ◽  
Super Duplex Stainless Steel ◽  
Σ Phase ◽  
Comprehensive Properties

The changes of microstructures, element distribution, and comprehensive properties were studied to explore their interactions with each other, induced by solution treatment of UNS S32750 super duplex stainless steel. The results showed that the ferrite content improved, while the austenite content declined as the temperature increased. From 900 to 1000 °C, the σ phase existing at α/γ grain boundaries and in ferrite grains gradually dissolved. At 1050 °C, the microstructures consisted of only ferrite and austenite. From 1050 to 1300 °C, the Cr2N precipitated in ferrite and gradually grew and coarsened. The impact energy and pitting potential of UNS S32750 first improved and then weakened, while the hardness is the opposite, owing to the combined effects of element distribution, microstructures, and precipitates. In the presence of the σ phase, the corrosion resistance and mechanical properties of UNS S32750 correspond directly to the σ phase fraction. Subsequently, the rise in temperature promoted γ → α phase transformation, and the elements partitioning ratios of Cr and Mo declined, resulting in reduced toughness and corrosion resistance and a rise in hardness. Consequently, when the solution treatment temperature is 1050 °C, the α/γ ratio of UNS S32750 approached 1:1, with excellent overall properties.

SANDVIK APM 2327

Alloy Digest ◽  
2018 ◽  
Vol 67 (12) ◽  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Duplex Stainless Steel ◽  
Tensile Properties ◽  
Corrosion Fatigue ◽  
Heat Treating ◽  
Fatigue Performance ◽  
Super Duplex Stainless Steel

Abstract Sandvik APM 2327 is a powder metallurgical hot isostatic pressed product that is a super duplex stainless steel with improved mechanical properties, corrosion resistance, and superior corrosion fatigue performance over conventional duplex grades. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SS-1299. Producer or source: Sandvik Materials Technology.

Investigation on mechanical, corrosion resistance and antibacterial properties of Cu-bearing 2205 duplex stainless steel by solution treatment

RSC Advances ◽  
2016 ◽  
Vol 6 (114) ◽  
pp. 112738-112747 ◽  
Author(s):  
Jinlong Zhao ◽  
Chunguang Yang ◽  
Dawei Zhang ◽  
Ying Zhao ◽  
M. Saleem Khan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Antibacterial Properties ◽  
Solution Treatment ◽  
2205 Duplex Stainless Steel ◽  
Antibacterial Performance ◽  
Solution Treated ◽  
Mechanical Properties And Corrosion

Solution treated 2205-Cu DSS with strong antibacterial performance against M. salsuginis showed appropriate mechanical properties and corrosion resistance.

scholarly journals The Microstructure, Mechanical Properties, and Corrosion Resistance of UNS S32707 Hyper-Duplex Stainless Steel Processed by Selective Laser Melting

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1012 ◽  
Author(s):  
Feng Shang ◽  
Xiaoqiu Chen ◽  
Zhiyong Wang ◽  
Zuchun Ji ◽  
Fei Ming ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Selective Laser Melting ◽  
Solution Annealing ◽  
Ocean Engineering ◽  
Laser Melting ◽  
Complex Shapes ◽  
Mechanical Properties And Corrosion

UNS S32707 hyper-duplex stainless steel (HDSS) parts with complex shapes for ocean engineering were prepared by selective laser melting (SLM) process. In the process of SLM, the balance between austenite and ferrite was undermined due to the high melting temperature and rapid cooling rate, resulting in poor ductility and toughness. The solution annealing was carried out with various temperatures (1050–1200 °C) for one hour at a time. The evolution of microstructures, mechanical properties, and corrosion resistance of UNS S32707 samples prepared by SLM was comprehensively investigated. The results indicate that a decrease in nitrogen content during the SLM process reduced the content of austenite, and a nearly balanced microstructure was obtained after appropriate solution annealing. The ratio between ferrite and austenite was approximately 59.5:40.5. The samples with solution treated at 1150 °C and 1100 °C exhibited better comprehensive mechanical properties and pitting resistance, respectively.

scholarly journals Selective Laser Melting of Duplex Stainless Steel 2205: Effect of Post-Processing Heat Treatment on Microstructure, Mechanical Properties, and Corrosion Resistance

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2468 ◽  
Author(s):  
Papula ◽  
Song ◽  
Pateras ◽  
Chen ◽  
Brandt ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Selective Laser Melting ◽  
Crystallographic Texture ◽  
Post Processing ◽  
Laser Melting ◽  
Mechanical Properties And Corrosion

Additive manufacturing (AM) is a rapidly growing field of technology. In order to increase the variety of metal alloys applicable for AM, selective laser melting (SLM) of duplex stainless steel 2205 powder and the resulting microstructure, density, mechanical properties, and corrosion resistance were investigated. An optimal set of processing parameters for producing high density (>99.9%) material was established. Various post-processing heat treatments were applied on the as-built predominantly ferritic material to achieve the desired dual-phase microstructure. Effects of annealing at temperatures of 950 °C, 1000 °C, 1050 °C, and 1100 °C on microstructure, crystallographic texture, and phase balance were examined. As a result of annealing, 40–46 vol.% of austenite phase was formed. Annealing decreased the high yield and tensile strength values of the as-built material, but significantly increased the ductility. Annealing also decreased the residual stresses in the material. Mechanical properties of the SLM-processed and heat-treated materials outperformed those of conventionally produced alloy counterparts. Using a scanning strategy with 66° rotation between layers decreased the strength of the crystallographic texture. Electrochemical cyclic potentiodynamic polarization testing in 0.6 M NaCl solution at room temperature showed that the heat treatment improved the pitting corrosion resistance of the as-built SLM-processed material.

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