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ABSTRACT Thin films of metallic glasses have many practical values as a result of their extremely homogeneous and disordered atomic structures.1 Recently, results were reported on tests of a film alloy of iron (Fe), boron (B), and silicon (Si) that showed excellent physical and magnetic properties compared to a crystalline alloy.2 The film (Fe78B13Si9) was found suitable for extremely low core loss in distribution, power transformers, and motors. It combined high induction and superb magnetic properties at frequencies, induction, and operating temperatures. Results showed the film could be used in inductors, current transformers, and other devices requiring high permeability and low core loss at low frequencies. Subsequently, three new metallic films with improved physical and magnetic properties were developed. The new films had structures of Fe81B13.5Si3.5C2, Fe66Co18B15Si1, and Fe77Cr2B16Si5. Detailed information on these films has been documented.3 In addition to the Fe-B-Si glasses, an iron-nickel (Ni)-molybdenum (Mo)-glass, Fe40Ni38Mo4B18, was developed. This glass had a high content of corrosion-resistant elements (Ni and Mo) compared to the other glasses. Information on the internal structures and properties of this glass have been reported elsewhere.4-5 Properties of the Fe81B13.5Si3.5C2 glass are balanced such that the films are useful in pulse transformers, magnetic amplifiers, power transformers, current tranducers, and other devices requiring a square-loop, high-saturation material. This film also offers a unique combination of high resistivity, high saturation induction, and very low core loss, making it suitable for use from low to high frequencies. The film of Fe66Co18B15Si1 exhibits the highest saturation induction of any amorphous alloy available commercially. In addition, it possesses very low core loss and is designed ideally for pulse applications
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (0.96)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (0.71)
ABSTRACT Natural waters are used extensively in many industries to remove heat from products and components. In the past, the corrosion of pipeline steels exposed to these waters has been mitigated with chromate-based inhibitors, which are strong oxidizers and biocides.1 Although chromates have been effective, health and toxicity concerns have mandated the discontinuation of this inhibitor system. Sodium molybdate (Na2MoO4) has been proposed as a replacement for chromates, but little is known of its ability to inhibit corrosion of steel in low-conductivity natural cooling waters. Although studies have examined its efficacy in distilled waters, in solutions with high ion concentrations, and in low-conductivity natural water, the hydrodynamics of these systems were static or undefined and the solution flow rate was fixed.1-7 Little work has been done in environments containing low concentrations of anions under various flow conditions. Hydrodynamics are recognized as a critical factor controlling the rate of oxygen and inhibitor transport to the surface, as well corrosion product removal. Persistency of the inhibitor is a function of hydrodynamic shear stresses at the surface. While studies have examined the effect of solution flow rate on the performance of inhibitors, there has been little work with Na2MoO4.8-9 There are many variables that may influence the ability of an inhibitor to reduce corrosion in a given solution, perhaps the most important of which are the solution flow rate and the inhibitor concentration. This study examined the efficacy of Na2MoO4 as a corrosion inhibitor for a common pipeline steel
- Geology > Mineral (0.46)
- Geology > Geological Subdiscipline > Geomechanics (0.34)
- Water & Waste Management > Water Management (1.00)
- Materials > Chemicals (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
ABSTRACT Sensitization of iron- or nickel-based alloys is caused by formation of a chromium-depleted layer at the grain boundary, where passivation is difficult. The selective dissolution of grain boundary zones deficient in chromium (Cr) results in intergranular corrosion (IGC). Since Inconel alloys usually contain 15% to 20% Cr, an analogous IGC problem was studied.1-5 Microscopic examination of failed UNS N06600(1) alloy (alloy 600) tube U-bend specimens that had been exposed to deoxygenated water at elevated temperatures showed intergranular stress corrosion cracking (IGSCC) along the axis of the U-bend near the apex, where intergranular fracture was found.4 The constant strain rate test on alloy 600 with and without heat treatment resulted in differing stress-strain curves.4 Since semi- or continuous precipitation along grain boundaries may alter local deformation characteristics, the difference probably was caused by chromium carbide (Cr3C2) precipitation that resisted stress corrosion cracking (SCC) in deaerated water at high temperature. Low temperature SCC of sensitized alloy 600 in tetrathionate and thiosulfate solutions was studied to identify the role of dissolved sulfur in the cracking process.6,7 The mean crack rate decreased proportionally with the logarithm of the thiosulfate concentration in air-saturated 1.3% boric acid (H3BO3) at 40°C in the range of 104 to 106 M. A maximum crack velocity was determined by constant deflection tests for sensitized alloy 600 controlled at 0.0 mVSCE in 0.5 M sodium thiosulfate (Na2S2O3) at 22°C.7 Constant load tests under controlled potentials demonstrated the sensitized alloy was susceptible to SCC in thiosulfate only when pH level was lowered to 3. The failure was a
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (0.70)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (0.55)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (0.48)
ABSTRACT Ferritic stainless steels (SS) have not found wide acceptance in the chemical industry because their corrosion resistance, weldability, and toughness are inferior to austenitic SS. Attempts have been made to improve those properties by increasing the alloy content and limiting interstitial levels, but the resulting alloys have not achieved much market success. Of the commercially developed alloys, the low interstitial or superferritic SS have been the most successful (e.g., type 444, an 18Cr-2Mo alloy). The low interstitial level of the superferritics improves their toughness and resistance to intergranular corrosion (IGC). Molybdenum (Mo) and an increased chromium (Cr) level improves corrosion resistance, particularly to pitting. Despite overall improvement, the superferritics lack the toughness and general corrosion resistance of austenitic SS. Early studies reported briefly the beneficial effect of vanadium (V) on the pitting resistance and impact properties of ferritic SS.1-4 More recent studies have confirmed beneficial effects, although V was found less effective than Mo in conferring pitting resistance.5,6 Because of its beneficial effects, V might improve the more deficient properties of ferritic SS. Polarization and general corrosion characteristics of V-bearing, low-interstitial ferritic SS have been studied as part of a broader program examining effects of V on corrosion resistance of SS. Results from some other studies in that program have been published.5-7 Early studies on ferritic and austenitic SS with conventional interstitial levels (800 ppm C) showed V had a slightly beneficial effect on passivation and corrosion in sulfuric acid (H2SO4) and a variable effect on stress corrosion cracking and resistance to IGC.2,8-11 Recent studies have confirmed the generally beneficial effect of V on passivation in austenitic and low-
- North America > United States (0.46)
- Africa > South Africa (0.29)
- Europe > United Kingdom (0.28)
- Materials > Chemicals (0.89)
- Materials > Metals & Mining > Steel (0.85)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
ABSTRACT: The internation.al pipeline network is ever increasing and some of these lines are already reaching an age of 20 years or more. It is, therefore that operators: are asking for the technology to Inspect and assess the state of their pipeline installations. State of the art intelligent pigs can detect a variety of flaws and defects from geometric anomalies to metal loss features and cracks. This paper will introduce how the integrity assessment of offshore pipelines can be achieved by the use of these in-line inspection tools. Special consideration will be given to the increasing demand for base line surveys ("fingerprinting") of newly constructed/lines and the special problems associated with thick walled offshore pipelines. A newly developed fitness-for-purpose evaluation program Will be Introduced which allows the assessment of individual pipeline sections or entire installations based on the data collected by use of intelligent pigs and the loading- and material parameters known to the operator. 1. INTRODUCTION Pipelines constitute one of the safest and most economical means to transport large quantities of oil and oil related products, as well as gas. However the international pipeline networks are growing in age and operators therefore require equipment and procedures to assess the true state of their pipelines. It is for this reason that in-line inspection tools have been developed since the 1960" s. Modern intelligent Pigs utilize a variety of non-destructive testing techniques to Inspect pipelines for a variety of potential flaws and defects. In recent years operators have also started to run base-line surveys of newly constructed pipelines in order to obtain a "fingerprint" of the line which can be used as a reference for later inspections. This paper will introduce how the integrity assessment of pipelines can be achieved by use of modern intelligent pigs.
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Offshore pipelines (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (0.90)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (0.69)
Abstract: Coflexip and IFP are carrying out an extensive research and development program to investigate the behavior of aluminium alloys as a substitute for both carbon steel used in the armour layers and for the stainless steel internal carcass in order to reduce the weight of the flexible. The results obtained in laboratory tests on the feasibility of using aluminium alloys have been confirmed by nine months of testing on three prototypes immersed in the Mediterranean Sea. The use of aluminium permits a reduction in weight of up to 40 % as well as an increase in the laying depth. 1 Introduction Due to the increasing depth of offshore oil and gas production it is necessary to reduce the weight or to increase the mechanical characteristics of the flexible risers and flowlines used to link subsea equipment to floating production units. Several solutions to this problem have been studied, namely the use of composite materials and aluminium alloys. Use of composite materials in the armours has been investigated and a flexible prototype of six hundred meters length has been immersed eighteen months ago in the Brazil sea and is still operating without any problem. This reduces the total weight of the pipe by 20% but increases the price compared to a conventional flexible. On the other hand, the use of aluminium alloys offers the advantages of even greater weight reduction because we can replace more steel than in the case of composites, easy formability and competitive price, but with some limitations in corrosion behavior and mechanical characteristics. 2. Coflexip flexible structure 1. an interlocked internal carcass. Its purpose is mainly to prevent collapse of the inner sheath should, by accident, the external sheath is torn out and external hydrostatic pressure applies directly onto the inner sheath.
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (0.96)
ABSTRACT: Unocal has been operating offshore natural gas and condensate production facilities in the Gulf of Thailand since 1981, and has employed a self-imposed inspection program since 1990 that now encompasses over 750 pressure vessels. The motivations for effecting this program are safety and loss-prevention The program is implemented through a systematic and cost-effective plan of engineering assessment, field inspection, and maintenance. The inspection scope is determined from a risk assessment that considers the generic nature of the vessels. Inspections are conducted by Unocal engineers and qualified inspectors. Maintenance and monitoring activities assist in keeping the vessels in fit-for-purpose condition. INTRODUCTION The Unocal operation in the Gulf of Thailand has expanded considerably since start-up in 1981. Approximately 800 MMscf of natural gas and 30,000 bbl of condensate are now being produced daily on 46 wellhead platforms, transported through 300 miles of interfield pipelines, and processed through over 750 pressure vessels on 8 major processing platforms. One safeguard to protect such an extensive investment is a properly executed pressure vessel inspection and maintenance program. The basics of this plan were originally developed for offshore platforms, but much of the logic is equally applicable to pressure vessel systems (Ref. 11). The plan also builds on a program proposed by DnV Technology & Services (Ref. 9). The details of the Unocal program provide a systematic, but flexible, framework for determining vessel inspection requirements that comply with the intent of the codes and recommended practices The AIM Program is administered by the Inspection & Maintenance Group of Production Engineering, which is organized according to Fig. 2. The inspection work is carried out by Unocal engineers and a dedicated offshore inspection team that is complemented by contractor expertise when necessary. Extensive field support is also required for vessel preparation and restoration to service.
- Asia (0.70)
- North America > United States > California (0.28)
- Health, Safety, Environment & Sustainability > Safety (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (0.94)
- (3 more...)
ABSTRACT: Sandvik SAF 2507 (UNS S32750) is a ferritic-austenitic stainless steel for service in highly corrosive conditions. It belongs to the group of so called super duplex stainless steels. Typical applications are seawater handling and process systems for oil and gas industry, seawater cooling, piping systems for refineries and petrochemical plants where the properties of standard duplex steels like SAF 2205 (UNS S31803) are not sufficient. This lecture will present results from welding trials with TIG, MMA and submerged-arc welding in tube and plate with thicknesses from 1.65 mm up to 20 mm. Mechanical data,. as tensile strength, impact properties, ductility as well as microstructure and pitting corrosion resistance data will be presented. For comparison some data from dissimilar joining of Sandvik SAF 2507 to Zeron 100 will be given. INTRODUCTION SAF 2507 (UNS 532750) is a duplex stainless steel for service in highly corrosive conditions. It belongs to the group of so called super duplex stainless steels. Typical applications are seawater handling and process systems for oil and gas industry, seawater cooling, piping systems for refineries and petrochemical plants where the properties of standard duplex steels like SAF 2205 (UNS S31803) are not sufficient. In many cases SAF 2507 will be a substitute for the 6% Mo austenitic stainless steels. The reason why there has to be a recommended min. heat input is that too low welding parameters will give a rapid cooling followed by a high ferrite content and due to the low solubility of nitrogen in the ferrite, chromium nitrides will precipitate. This can lower the corrosion resistance. Compared with standard duplex steels the reformation of austenite is extremely good in Sandvik SAF 2507 and the min. heat input is therefore 0.2 kJ/mm, instead of 0.5 kJ/mm, which is normally recommended for duplex steels.
- Materials > Metals & Mining > Steel (1.00)
- Energy > Oil & Gas (1.00)
- Well Completion (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers (1.00)
ABSTRACT: Super Duplex stainless steel pipework has peen widely used in a range of process and seawater environments that may be contaminated with hydrogen sulphide, chloride, CO2 and water. sup∼r duplex stainless steel, Zeron 100 belng an example, is chosen because of its resistance to a wide range of corrosive environments and because of its high mechanical properties. This paper describes the welding of pipework sizes typically used in process fluid and sea water service. The general rules for welding Zeron 100 are outlined. Consideration is given to the four basic factors associated with welding. Specific welding procedures and techniques are detailed. The metallurgical, mechanical and corrosion resistance characteristics of the joints are considered. The pipe diameter range considered is 19 to 220mm with wall thicknesses between 1.6 and 12.7mm. Manual welding is widely used because of its versatility and simplicity. GTA and SMA welding are both used, process selection being based on pipe size and productivity factors. A range of welding procedures are detailed including welds completed on thinner sections without the use of filler metal. INTRODUCTION Super Duplex Stainless Steels are used in the offshore industry because of their very good corrosion resistance, high strength and their strength to weight ratio. The steels are highly resistant to sea water pitting and crevice corrosion and to both sulphide and chloride stress corrosion cracking. The first super duplex stainless steels, UNS S32760 (Zeron 100), came into service in 1985. Super Duplex stainless steels are now extensively utilised in the oil and gas industry for a wide range of both process and sea water systems. Steel meeting UNS S32760 is used for pipe work systems ego firewater, sea water, process pipe work system and flow lines, and for installation facilities, ego manifolds, heat exchangers, caissons, valves, pumps and pressure vessels.
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
ABSTRACT: Super duplex stainless steels (having a PREN of at least 40) are widely used in the offshore industry because of their combination of corrosion resistance and high strength. This generic class of materials is widely used in process pipework and seawater systems. Pipe work systems are fabricated by welding, which inevitably results in distortion and strain in the weld zone. The amount of welding induced strain is determined by the material characteristics, the joint design, welding techniques and section thickness. In pipe welds, some angular distortion occurs and the joint "pulls in". The level of deflection experienced increases with increasing section thickness. This gross deflection results in strain hardening in the root zone, although no metallurgical changes were observed and the normal phase balance is retained_ The changes in hardness with increasing strain is due to strain hardening. The resultant hardness may, on occasions, slightly exceed the presently accepted NACE requirements for duplex stainless steel welds_ This paper details the relationship between section thickness, welding techniques, joint deflection and change in root hardness. The results of metallurgical examination and corrosion testing (sulphide SCC and Ferric Chloride ASTM G48A testing) of samples are reported and considered in relation to (particularly) NACE requirements. The implications of welding procedure design and pipework service condition are considered. INTRODUCTION Super duplex stainless steels (having a PREN of at least 40 where the PREN = %Cr + 3.3% Mo + 16% N) are widely used in the offshore industry because of their combination of corrosion resistance, strength and toughness. This generic class of materials is widely used as pipework, for example, in process environments containing hydrogen sulphide, carbon dioxide and chlorides, and in seawater systems. Welded joints are inevitably stressed due to fabrication related stresses. These stresses lead to distortion and deformation.
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers (1.00)