Effect of Reeling Simulation on the Mechanical Properties of New Duplex Stainless Steel for Line Pipe

Author(s):  
Hidenori Shitamoto ◽  
Masayuki Sagara ◽  
Hisashi Amaya ◽  
Nobuyuki Hisamune ◽  
Daisuke Motoya ◽  
...  

Corrosion resistant alloys (CRAs) such as martensitic and duplex stainless steels (DSS) are used as a flow line material in corrosive wet gas environments (i.e., carbon dioxide and hydrogen sulfide environments). A new DSS which consists of 25mass%Cr - 5mass%Ni - 1mass%Mo - 2.5mass%Cu has been developed for line pipe usage in slightly sour environments. There are several methods currently being used to install offshore oil and gas pipelines. The reel-lay process is fast and one of the most effective offshore pipeline installation methods for seamless, ERW, and UOE line pipes with outside diameters of 18 inches or less. In the case of the reel-laying method, line pipes are subjected to plastic deformation multiplication during reel-laying. Thus, it is important to understand the change of the mechanical properties of line pipes before and after reel-laying. In this study, full-scale reeling (FSR) simulations and small-scale reeling (SSR) simulations were performed to investigate the effect of cyclic deformation on the mechanical properties of the new DSS for line pipe. Furthermore, investigation of the most susceptible temperature range to cracking and sulfide stress cracking (SSC) tests were performed in slightly sour conditions.

Author(s):  
Hidenori Shitamoto ◽  
Nobuyuki Hisamune

There are several methods currently being used to install offshore oil and gas pipelines. The reel-lay process is fast and one of the most effective offshore pipeline installation methods for seamless, ERW, and UOE line pipes with outside diameters of 18 inches or less. In the case of the reel-laying method, line pipes are subjected to plastic deformation multiplication during reel-laying. It is thus important to understand the change of the mechanical properties of line pipes before and after reel-laying. Therefore, full-scale reeling (FSR) simulations and small-scale reeling (SSR) simulations are applied as evaluation tests for reel-laying. In this study, FSR simulations were performed to investigate the effect of cyclic deformation on the mechanical properties of weldable 13Cr seamless line pipes. Furthermore, SSR simulations were performed to compare the results obtained by FSR simulations.


2014 ◽  
Vol 32 (3-4) ◽  
pp. 101-128 ◽  
Author(s):  
Mariano Kappes ◽  
Mariano Iannuzzi ◽  
Raúl B. Rebak ◽  
Ricardo M. Carranza

AbstractLow-alloy steels (LAS) are extensively used in oil and gas (O&G) production due to their good mechanical properties and low cost. Even though nickel improves mechanical properties and hardenability with low penalty on weldability, which is critical for large subsea components, nickel content cannot exceed 1-wt% when used in sour service applications. The ISO 15156-2 standard limits the nickel content in LAS on the assumption that nickel concentrations above 1-wt% negatively impact sulfide stress cracking (SSC) resistance. This restriction excludes a significant number of high-strength and high-toughness alloys, such as Ni-Cr-Mo (e.g., UNS G43200 and G43400), Ni-Mo (e.g., UNS G46200), and Ni-Cr-Mo-V grades, from sour service applications and can be used only if successfully qualified. However, the standard is based on controversial research conducted more than 40 years ago. Since then, researchers have suggested that it is the microstructure that determines SSC resistance, regardless of Ni content. This review summarizes the advantages and disadvantages of nickel-containing LAS in terms of strength, weldability, hardenability, potential weight savings, and cost reduction. Likewise, the state of knowledge on the effect of nickel on hydrogen absorption as well as SSC initiation and propagation kinetics is critically reviewed.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5771
Author(s):  
Luis Manuel Quej-Ake ◽  
Jesús Noé Rivera-Olvera ◽  
Yureel del Rosario Domínguez-Aguilar ◽  
Itzel Ariadna Avelino-Jiménez ◽  
Vicente Garibay-Febles ◽  
...  

The review presented herein is regarding the stress corrosion cracking (SCC) phenomena of carbon steel pipelines affected by the corrosive electrolytes that comes from external (E) and internal (I) environments, as well as the susceptibility and tensile stress on the SCC. Some useful tools are presented including essential aspects for determining and describing the E-SCC and I-SCC in oil and gas pipelines. Therefore, this study aims to present a comprehensive and critical review of a brief experimental summary, and a comparison of physicochemical, mechanical, and electrochemical data affecting external and internal SCC in carbon steel pipelines exposed to corrosive media have been conducted. The SCC, hydrogen-induced cracking (HIC), hydrogen embrittlement, and sulfide stress cracking (SSC) are attributed to the pH, and to hydrogen becoming more corrosive by combining external and internal sources promoting cracking, such as sulfide compounds, acidic soils, acidic atmospheric compounds, hydrochloric acid, sulfuric acid, sodium hydroxide, organic acids (acetic acid, mainly), bacteria induced corrosion, cathodic polarization, among others. SCC growth is a reaction between the microstructural, chemical, and mechanical effects and it depends on the external and internal environmental sources promoting unpredictable cracks and fractures. In some cases, E-SCC could be initiated by hydrogen that comes from the over-voltage during the cathodic protection processes. I-SCC could be activated by over-operating pressure and temperature at flowing media during the production, gathering, storage and transportation of wet hydrocarbons through pipelines. The mechanical properties related to I-SCC were higher in comparison with those reviewed by E-SCC, suggesting that pipelines suffer more susceptibility to I-SCC. When a pipeline is designed, the internal fluid being transported (changes of environments) and the external environment concerning SCC should be considered. This review offers a good starting point for newcomers into the field, it is written as a tutorial, and covers a large number of basic standards in the area.


Author(s):  
Rolf Nyborg ◽  
Arne Dugstad

In many offshore oil and gas projects under development, the pipeline costs are a considerable part of the investment and can become prohibitively high if the corrosivity of the fluid necessitates the use of corrosion resistant alloys instead of carbon steel. Development of more robust and reliable methods for internal corrosion control can increase the application range of carbon steel and therefore have a large economic impact. Corrosion control of carbon steel pipelines has traditionally often been managed by the use of corrosion inhibitors. The pH stabilization technique has been successfully used for corrosion control of several large wet gas condensate pipelines in the last few years. Precipitation of scale and salts in the pipeline and process equipment creates further challenges when formation water is produced. Different corrosion prediction models are used in the industry to assess the corrosivity of the transported fluid. An overview of the present models is given together with a link to fluid flow modeling.


CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 244-253 ◽  
Author(s):  
S. U. Koh ◽  
J. S. Kim ◽  
B. Y. Yang ◽  
K. Y. Kim

Abstract The purpose of this experiment was to evaluate the effect of microstructure on sulfide stress cracking (SSC) properties of line pipe steel. Different kinds of microstructures, with chemical compositions identical to one steel heat, were produced by various thermomechanically controlled processes (TMCP). Coarse ferrite-pearlite, fine ferrite-pearlite, ferrite-acicular ferrite, and ferrite-bainite microstructures were investigated with respect to corrosion properties, hydrogen diffusion, and SSC behavior. SSC was evaluated using a constant elongation rate test (CERT) in a NACE TM0177 solution (5% sodium chloride [NaCl] + 0.5% acetic acid [CH3COOH], saturated with hydrogen sulfide [H2S]). The corrosion properties of steels were evaluated by potentiodynamic and linear polarization methods. Hydrogen diffusion through steel matrix was measured by an electrochemical method using a Devanathan-Stachurski cell. The effect of microstructure on cracking behavior also was investigated with respect to crack nucleation and propagation processes. Test results showed that ferrite-acicular ferrite microstructure had the highest resistance to SSC, whereas ferrite-bainitic and coarse ferritie-pearlitic microstructures had the lowest resistance. The high susceptibility to SSC inferritie-bainitic and coarse ferritic-pearlitic microstructures resulted from crack nucleation on hard phases such as grain boundary cementite in coarse ferritie-pearlitic microstructures and martensite/retained austenite (M/A) island in bainitic phases. Hard phase cementite at grain boundaries or M/A constituent in bainitic phases acted as crack nucleation sites and could be cracked easily under external stress; consequently, the susceptibility of steel to SSC increased. Metallurgical parameters including matrix structure and defects such as grain boundary carbides and inter-lath M/A constituents were more critical parameters for controlling SSC than the hydrogen diffusion rate.


CORROSION ◽  
10.5006/2724 ◽  
2018 ◽  
Vol 74 (7) ◽  
pp. 801-818
Author(s):  
Hans Husby ◽  
Philip Wagstaff ◽  
Mariano Iannuzzi ◽  
Roy Johnsen ◽  
Mariano Kappes

Nickel additions to low alloy steels improve mechanical and technological properties. However, Part 2 of ISO Standard 15156 limits the nickel content to a maximum of 1 wt% in oil and gas environments containing H2S because of controversial concerns regarding sulfide stress cracking. The objective of this work was to investigate the effect of nickel in solid solution in the ferrite phase on hydrogen stress cracking resistance. Ferritic/pearlitic research-grade low alloy steels with nominal nickel contents of 0, 1, 2, and 3 wt% were tested by the slow strain rate test method with cathodic hydrogen charging to −1.05 VAg/AgCl and −2 VAg/AgCl. No difference in fracture mode or morphology was found between the alloys. However, the plastic elongation ratios and reduction in area ratios decreased with increasing nickel content when tested at −2 VAg/AgCl. The direct and indirect effects of nickel, such as the influence of an increasing fraction of pearlite with increasing nickel content, are discussed.


2015 ◽  
Vol 55 (2) ◽  
pp. 415
Author(s):  
Steve Henzell

Australia's relative isolation and the harsh environment in Bass Strait have led to many innovations in offshore oil and gas developments. The initial developers were moving into frontier territory when Bass Strait was developed, with the harsh sea state and the water depths presenting major challenges. The original development of Bass Strait in the 1960s was tied to a wet gas pipeline philosophy, which was a novel step-out from normal industry practice. For example, the North Sea developments, which started shortly after Bass Strait, adopted dry gas export pipelines and required substantially larger platforms to process the gas for export. The cold waters of Bass Strait require an active hydrate management strategy and the success of hydrate inhibitors has been a key element in using wet gas pipelines. The initial development relied on methanol for hydrate inhibition, but this changed to a glycol-based hydrate inhibitor within 10 years of production start-up, due to challenges in the onshore production facilities. The use of mono-ethylene glycol for management of wet gas pipelines was demonstrated in Bass Strait. The success of the initial developments has given operators the confidence to pursue marginal field developments that rely on wet gas transport to the beach. The Minerva, Casino, Thylacine and Longtom gas field developments in Bass Strait have all adopted the same strategy, in part because of the confidence provided from operating the initial developments for many years.


CORROSION ◽  
1983 ◽  
Vol 39 (9) ◽  
pp. 364-370 ◽  
Author(s):  
J. C. Turn ◽  
B. E. Wilde ◽  
C. A. Troianos

CORROSION ◽  
10.5006/3590 ◽  
2020 ◽  
Vol 76 (12) ◽  
pp. 1207-1219
Author(s):  
A. Febbrari ◽  
R. Montani ◽  
C. Veronesi ◽  
M. Cavagnola ◽  
E. Brognoli ◽  
...  

UNS N06625 is a nickel-based superalloy used for oil and gas applications and commonly produced according to NACE MR0175 in the annealed/solution annealed condition. The annealing/solution annealing treatment makes the material corrosion resistant in the most challenging environments, in the presence of sulfides and chlorides at high pressure and temperature. However, thanks to its chemical composition, UNS N06625 can also be considered as an age-hardenable material whose mechanical strength can be improved by promoting the metastable second phase γ′′ precipitation into the γ matrix. However, the corrosion behavior of the aged alloy has never been investigated in NACE environments. This paper aims to understand the suitability of the age-hardened condition of UNS N06625 for oil and gas applications through the evaluation of the material corrosion performance in NACE level VII environments by using NACE TM0177 tests. Three heats of UNS N06625 have been produced and forged in different bar diameters: 152 mm (6 in), 203.2 mm (8 in), and 254 mm (10 in). Afterward, the bars have been annealed and age-hardened according to optimized time-temperature parameters and finally tested to assess their mechanical properties and resistance to stress corrosion cracking, sulfide stress cracking, galvanic-induced hydrogen stress cracking, and hydrogen embrittlement.


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