Mechanized welding of duplex steel thick-walled vessels

1967 ◽  
Vol 3 (6) ◽  
pp. 472-476
Author(s):  
I. I. Kumysh ◽  
V. A. Lutsyuk-Khudin ◽  
V. Ya. Saenko ◽  
G. G. Andrianov
Keyword(s):  
Duplex Steel ◽  
Mechanized Welding

Determination of Yield Stress in a Duplex Steel with α + γ Lamellar Structure

2018 ◽  
Vol 50 (1) ◽  
pp. 151-160 ◽  
Author(s):  
Yoon-Uk Heo ◽  
Joo-Hee Kang ◽  
Nam Hoe Heo ◽  
Sung-Joon Kim
Keyword(s):  
Yield Stress ◽  
Lamellar Structure ◽  
Duplex Steel

Study of the Thermal Diffusivity Variation in Thin Duplex Steel Plates Welded by GTAW Process

2018 ◽  
Vol 930 ◽  
pp. 460-465
Author(s):  
Evandro Giuseppe Betini ◽  
Maurilio Pereira Gomes ◽  
Cristiano Stefano Mucsi ◽  
Temístocles de Souza Luz ◽  
Marcos Tadeu D'azeredo Orlando ◽  
...  
Keyword(s):  
Thermal Diffusivity ◽  
Welding Process ◽  
Laser Flash ◽  
Nitrogen Atmosphere ◽  
Steel Plates ◽  
Digital Data ◽  
Flash Method ◽  
Temperature Profiles ◽  
Butt Weld ◽  
Duplex Steel

This study describes the thermal diffusivity of thin duplex steel plates in the thickness direction measured using the laser-flash method after welding. The work reports the experimental efforts in recording temperature profiles of the grade UNS S32304 duplex steel during autogenous welding. The butt weld autogenous joints were carried out by the GTAW (gas tungsten arc welding) process with either argon or argon - 2% nitrogen atmospheres. The amount of nitrogen in the heat affected regions, after welding, was measured and correlated with the variation of the thermal diffusivity of the studied material. The temperature profiles were obtained using k-type thermocouples connected to a digital data acquisition system. Different thermal cycles and thermal diffusivity values were observed in the heat-affected zone (HAZ) for both samples. In the solidified zone (SZ) was observed similar increase of the thermal diffusivity values for the plates welded with pure argon and argon plus nitrogen atmosphere.

Corrosion Behavior of Duplex Stainless Steel in Industrial White Liquor

CORROSION ◽  
10.5006/2558 ◽  
2017 ◽  
Vol 74 (5) ◽  
pp. 543-550 ◽  
Author(s):  
Luiza Esteves ◽  
Mônica M.A.M. Schvartzman ◽  
Wagner Reis da Costa Campos ◽  
Vanessa F.C. Lins
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Corrosion Rate ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Extrapolation Method ◽  
White Liquor ◽  
Duplex Steel ◽  
Kraft Mill ◽  
Lower Corrosion Rate

Specimens of lean duplex and duplex stainless steel were exposed at 200°C in industrial white liquor from a Brazilian kraft mill using an autoclave to simulate the same conditions of digester processing. Tafel extrapolation method and weight loss were used to evaluate corrosion behavior of duplex steel in white liquor. The higher alloy steel, although presenting a lower corrosion rate than the lean duplex, presents a more severe selective attack on ferrite, at 200°C and 1.8 MPa, after Tafel extrapolation method in industrial white liquor.

Hydrogen Induced Stress Cracking of Superduplex Steels: Effect of Operation Temperature

2018 ◽  
Author(s):  
Lars M. Haldorsen ◽  
Bård Nyhus ◽  
Gisle Rørvik
Keyword(s):  
Cathodic Protection ◽  
Life Time ◽  
Oil Companies ◽  
Stress Cracking ◽  
Operation Temperature ◽  
Induced Stress ◽  
Duplex Steel ◽  
Future Revision ◽  
Cathodic Protection System ◽  
Guidelines And Recommendations

Duplex stainless steel has been used on subsea facilities since the mid 80-ties. The experiences with these materials have been relative good and only a few failures have been reported. However, BP and Shell experience some serious cracking of duplex steel in the mid 90-ties and in beginning of the century. The root cause of these failures was identified to be Hydrogen Induced Stress Cracking, HISC, where the hydrogen source was the cathodic protection system of the subsea facility. These and other similar failures resulted establishment of Joint Industry Projects, JIPs with financial and technical contribution from leading oil companies, contractors, material suppliers and research institutions as TWI, SINTEF and DNVGL. The objective of the JIPs was to establish practical usage limits for duplex stainless steels. The JIPs resulted in a recommended practice “DNV-RP-F112 - Design of duplex stainless subsea equipment exposed to cathodic protection.” This document minimized the failure rate of duplex steel components used subsea. However, since duplex steels components have been used on subsea facilities long before the guidelines and recommendations were issued, there are lot of components presently in use that may be overloaded compared to guidelines and recommendations. As a part of life time extension of one of Statoil’s long time producing fields, a HISC re-calculation of spools connecting SPSs to infield pipelines showed that many of the spools were exposed to stresses above the recommended stresses given in DNV-RP-F112. Since these recommendations were primarily based on testing at ambient seabed temperature (4°C), Statoil, together with SINTEF, started in 2016 a project where the aim was to evaluate the resistance against HISC as an effect of the operation temperature. The results of this project show that the critical net section stress/AYS (HISC resistance) increases with increasing temperature. Based on this, the before mentioned spools can be considered safe even though the spools are exposed to stresses above the recommendations in DNV-RP-F112. Further, the investigations show that the guidelines and recommendations given in DNV-RP-F112 may be conservative for temperatures above 4°C. It is therefore recommended to perform more testing to confirm and incorporate the findings from the present investigation in future revision of DNV-RP-F112.

scholarly journals Application of robotic and mechanized welding under disturbing factor conditions

2016 ◽  
Vol 2016 (7) ◽  
pp. 42-46 ◽  
Author(s):  
E.V. Shapovalov ◽  
◽  
V.V. Dolinenko ◽  
V.A. Kolyada ◽  
T.G. Skuba ◽  
...  
Keyword(s):  
Disturbing Factor ◽  
Mechanized Welding

Development and study of a material for mechanized welding of basic structures from nonmagnetic high-strength nitrided steel

2011 ◽  
Vol 2 (6) ◽  
pp. 612-617
Author(s):  
G. Yu. Kalinin ◽  
R. V. Bishokov ◽  
P. V. Mel’nikov ◽  
L. A. Berezovskaya ◽  
V. A. Mogil’nikov ◽  
...  
Keyword(s):  
High Strength ◽  
Nitrided Steel ◽  
Mechanized Welding

Pre-straining alters hydrogen-assisted cracking site and local hydrogen diffusivity in a nitrogen-doped duplex steel

2022 ◽  
Vol 207 ◽  
pp. 114272
Author(s):  
Milene Yumi Maeda ◽  
Motomichi Koyama ◽  
Hayato Nishimura ◽  
Osvaldo Mitsuyuki Cintho ◽  
Eiji Akiyama
Keyword(s):  
Hydrogen Diffusivity ◽  
Nitrogen Doped ◽  
Duplex Steel ◽  
Hydrogen Assisted Cracking

Investigation on the Microstructure Hardness for the Hot Compressed Duplex Steel

2022 ◽  
Vol 905 ◽  
pp. 30-37
Author(s):  
Shu Lan Zhang ◽  
Xiao Dan Zhang ◽  
Hai Feng Xu ◽  
Chang Wang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Optical Microscope ◽  
Ferrite Phase ◽  
Ferrite Formation ◽  
Average Hardness ◽  
Duplex Steel ◽  
Quench Temperature ◽  
Fluctuation Range ◽  
Scanning Electron

Effect of microstructure size and type on the hardness for the duplex steel were disclosed by using of optical microscope (OM), scanning electron microscope (SEM) and nanoindenter for the samples hot compressed under different temperature with reduction of 10%, 30%, 50% and 70%. OM and SEM were used to measure the average martensite lamellar width, space and indenter morphology. nanoindenter test characterized the microstructure hardness for the samples under different process. Experiment results show that martensite hardness for the sample hot compressed at 950°C has larger diversity than that of sample hot compressed at 1200°C. The martensite hardness fluctuation range for the sample compressed at 950°C is almost from about 7GPa to 12GPa, while, for the sample compressed at 1200°C, the fluctuation range is basically from about 9GPa to 12GPa. However, the average hardness for the samples hot compressed at 950°C is comparably smaller, which is related with lower quench temperature. The larger martensite hardness fluctuation is mainly related with induced ferrite formation and finer martensite lamellar width. For the ferrite phase, the hardness fluctuation range is lower.

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