Fatigue Evaluation of Super Duplex Stainless Steel after 17 Years of Service in a Dynamic Umbilical in the Åsgard Oil and Gas Field, Norway

2018 ◽  
Author(s):  
Kukuh W. Soerowidjojo ◽  
Daniel Svedberg
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Oil And Gas ◽  
Super Duplex Stainless Steel ◽  
Gas Field ◽  
Oil And Gas Field ◽  
Years Of Service ◽  
Fatigue Evaluation

Influence of Argon-Nitrogen Gas to Balance the Microstructure in the Welding of Super Duplex Stainless Steel

2016 ◽  
Vol 836 ◽  
pp. 165-172
Author(s):  
Suheni
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
Duplex Stainless Steel ◽  
Heat Input ◽  
Oil And Gas ◽  
Austenite Phase ◽  
Super Duplex Stainless Steel ◽  
Shielding Gas ◽  
Input Variables ◽  
Protective Gas

Super duplex stainless steel is steel that has a corrosion resistance and good mechanical strength so that used in industry especially in oil and gas and petrochemical industry. In use in the field is often used for the connection process by welding methods. To produce good welds, it should be noted that the welding procedures and parameters used , especially the heat input. In this study is used the heat input variables shielding gas composition to determine how much influence on the balance of ferrite - austenite phase structure in the weld stainless steels SAF 2507 super duplex with tungsten inert gas welding method (TIG). Heat input varied by applying different welding speed 1,3,4 and 5 mm /sec while the shielding gas is used 100 % argon, 98 % argon + 2 % nitrogen and 95 % argon + 5 % nitrogen. The result showed that at different welding speeds generated depth and width of the weld metal which is different. Likewise the use of protective gas will produce a different ratio wide and deep of weld metal which is different. By using protective gas 95 % argon + 5 % nitrogen squeak - ausenit phase, resulting in weld metal that is relatively balanced than others. On a slow welding in addition to produce a large heat input also produces weld metal hardness at high and affect the growth of the austenite phase. The higher the heat input ( 2,280 kJ / mm ) , the lower the austenite phase in the weld metal.

scholarly journals Development of UNS S 32760 super-duplex stainless steel produced in large diameter rolled bars

2013 ◽  
Vol 66 (2) ◽  
pp. 201-208
Author(s):  
Celso Antonio Barbosa ◽  
Alexandre Sokolowski
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Chemical Composition ◽  
Duplex Stainless Steel ◽  
Oil And Gas ◽  
Large Diameter ◽  
Processing Parameters ◽  
Chemical Compositions ◽  
Super Duplex Stainless Steel ◽  
Corrosion Properties

Nowadays super-duplex stainless is an important material for the Oil and Gas industries, especially for off-shore production. In deep water exploitation the reliability of production system is very important. Corrosion resistance for pitting of the high alloyed duplex stainless steels with high Mo and N content has to be achieved even in large diameters bars. Therefore, the present work deals with an improved super-duplex stainless steel for the production of large diameter rolled 6bars up to 152.40 mm (6 inches). Among the main improvements, the corrosion resistance evaluated both by the chemical method according to the ASTM G-48 method, as well as electrochemical methods, was achieved. During the production of such large dimensions, the precipitation of inter-metallics and nitrides after cooling from high temperatures was studied by changing the chemical composition using Thermo-Calc and evaluating the new proposed chemical compositions. Several alloy compositions were laboratory scale cast, and the austenite/ferrite balance as well as PREN pitting resistance equivalent number content was correlated to the microstructure and the corrosion properties obtained. It was thus possible to determine the ideal chemical composition and define the new processing parameters to produce the UNS S32760 grade (4501) according to the Norsok standard. The new material properties produced in a production full scale heat are also presented.

Dissimilar Metal Welding of Nitronic 50 HS® and 25% Cr Super Duplex Stainless Steel

2014 ◽  
Author(s):  
Nathan Nissley ◽  
Timothy D. Anderson ◽  
Fredrick F. Noecker ◽  
Caleb Roepke ◽  
Morgan Gallagher ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Intermetallic Compound ◽  
Duplex Stainless Steel ◽  
Heat Input ◽  
Oil And Gas ◽  
Super Duplex Stainless Steel ◽  
Compound Formation ◽  
Intermetallic Compound Formation ◽  
Compositional Gradients

High pressure tubing and associated tubing couplers are critical components required for the operational control of subsea oil and gas production equipment. Tubing couplers used in subsea oil and gas developments are commonly made from Nitronic 50 HS® (N50HS) due to its high strength, corrosion resistance, and resistance to galling. Nitronic couplers are typically welded to several dissimilar metals including super duplex stainless steel (SDSS) control tubing using SDSS filler metals such as AWS A5.9 ER2594. Recent evaluations have found that sigma (σ) phase forms in N50HS weldments and its effect is not broadly understood by industry. During N50HS solidification, Scheil solidification conditions establish compositional gradients in the unmixed zone located along the fusion line adjacent to the N50HS base metal. This solidification-induced segregation promotes compositions that are susceptible to interdendritic intermetallic compound formation when they are reheated by subsequent weld passes such as in multipass welding or at weld start-stop locations. Decreasing heat input is a common approach to reduce or eliminate the formation of intermetallic compounds in SDSS. Although decreasing heat input can reduce the amount of energy available to drive the solid state transformation from ferrite to σ, it does not change the solidification mode (AF) or solidification conditions from Scheil to para-equilibrium within the range of cooling rates possible with arc welding processes. As such, the compositional gradients that promote intermetallic compound formation along the N50HS fusion line can only be minimized through heat input control and cannot be eliminated in arc welds regardless of the heat input used. The effects of σ on toughness and corrosion resistance of Nitronic weldments were evaluated. N50HS solidified samples with up to 2 volume percent σ were found to have CVN of >40J at −40°C, and no evidence of pitting at 25°C in the ASTM G48 test.

ZERON 100

Alloy Digest ◽  
1993 ◽  
Vol 42 (11) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Duplex Stainless Steel ◽  
Heat Treating ◽  
Super Duplex Stainless Steel ◽  
Corrosion Performance ◽  
Temperature Performance ◽  
Offshore Oil

Abstract ZERON 100 is a super duplex stainless steel which is manufactured to give a guaranteed corrosion performance by using an equation to control the chemistry in those elements which will determine the corrosion resistance of the material. Major usages in seawater applications, particularly offshore oil gathering systems. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance as well as heat treating, machining, and joining. Filing Code: SS-555. Producer or source: Weir Material Services Ltd.

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