Academic literature on the topic 'ASTM A105 carbon-steel pipe'

In this study, the cause of failure of a low-carbon steel pipe meeting standard KS D 3562 (ASTM A135), in a district heating system was investigated. After 6 years of operation, the pipe failed prematurely due to pitting corrosion, which occurred both inside and outside of the pipe. Pitting corrosion occurred more prominently outside the pipe than inside, where water quality is controlled. The analysis indicated that the pipe failure occurred due to aluminum inclusions and the presence of a pearlite inhomogeneous phase fraction. Crevice corrosion occurred in the vicinity around the aluminum inclusions, causing localized corrosion. In the large pearlite fraction region, cementite in the pearlite acted as a cathode to promote dissolution of surrounding ferrite. Therefore, in the groundwater environment outside of the pipe, localized corrosion occurred due to crevice corrosion by aluminum inclusions, and localized corrosion was accelerated by the large fraction of pearlite around the aluminum inclusions, leading to pipe failure.

In these studies, both dynamic and static tests were conducted on pressurized pipe. Dynamic tests were run on 1 in. Schedule 40 and Schedule 10 seamless 304 stainless steel pipe. Welded 1 in. Schedule 40 304 stainless steel pipe and seamless carbon steel (ASTM A106) pipe were tested statically. Internal pressures varied from 1000 psi to 3000 psi. In these tests, axial bending stresses from either inertial loads or static loads were superposed on to the initial pressure stresses. Strain gages were used to measure the cyclic strains on the outer walls of the pipe. Measurements indicated that ratcheting occurred primarily in the hoop direction and varied from a maximum at the top and bottom of the pipe that had the highest bending stresses to zero at the neutral axis. Though ratcheting occurred primarily in the hoop direction, some ratcheting in the axial direction was observed in 304 stainless steel pipe in both static and dynamic tests. Axial ratcheting was insignificant in the carbon steel pipe. Data obtained from these tests are presented. Measured ratcheting strains are compared to approximations of Beaney, Edmunds and Beer and to finite element computations.

The current study was absorbed on corrosion of ASTM A106 grade B -02 seamless carbon steel boiler pipes. Beyond corrosion experiments in corrosive medium with varying pH values, the weight lost in addition to corrosion rate (m.p.y) values were computed. The weight loss of boiler tube specimens exposed to corrosive liquid was shown to rise as the exposure period of the specimens increased. The results of the microstructure imaging showed that a de-carburized film of 240 µm thickness was shaped on the fireside of the pipe boiler, with ferrite and a few phases of pearlite. On the water lateral side, it was revealed that boiler pipe failure begins with small rust particles that expand to greater sizes and form scales that are displaced from the boiler pipe's surface. On the surfaces of the boiler pipe water side, several pits with crevice corrosion were observed. The corrosion amounts were discovered to decrease when the specimens' exposure time to corrosive environments and hydrogen ion concentration contents increased (pH). The findings of mechanical characteristic values such as hardness, yield strength, and tensile strength revealed that the waterside had higher values than the fireside, while the middle of the pipe had reasonable values. The findings also demonstrated that at low pH values, a tiny size of rust was created on the boiler tube specimen surface. However, at high pH values of corrosive medium, big sizes of corrosion rust were observed on the specimen surfaces.

Defect size of wall thinned pipe is measured by using Speckle Shearing Interferometry (SSI) and Digital Image Correlation (DIC) techniques. A wall thinned defect of a carbon steel pipe was typically caused by flow accelerated corrosion (FAC). As wall thinned pipe can cause a huge accident at the nuclear power plant (NPP), a wall thinned defect should be detected for structure safety. SSI is one of the optical nondestructive techniques and can provide to inspect in real-time and to measure on the whole visible area at a time. DIC is a kind of the visual testing method. This method which uses a stereo vision system can measure the deformation or strain/stress of a structure in 3D. In this paper, ASTM A106 Gr.B carbon steel pipe is used as specimen. When the pressure load is provided by the pressure pump, the out-of-plane deformation along the longitudinal direction of a pipe can be detected quantitatively. Both results of SSI and DIC experiments are compared.

Catastrophic failure is often associated with a large temperature rise. This situation may lead to a drastic deterioration in material strength where a cooling system is important for a smooth system plant operation to prevent catastrophic failure to its equipments, parts or processes. In this study, a part of a failed closed recirculation system water cooling pipe in a steel manufacturing plant in Malaysia has been investigated for detailed failure analysis. A steam leakage of a water cooling pipe with a closed recirculation system operation made of ASTM A106/A (Carbon Steel Pipes for high temp service) was detected. The aim of this study is to explore the evidence related to the water cooling pipe leakage and to investigate the cause of failure. Detailed investigation was carried out by visual inspection, optical microscopy and hardness testing. With the evidence obtained, due to presence of water scale and prolonged overheating, decarburization had occurred. During decarburization, it was found that carbon elements from inner surface tube had depleted through the outer tube surface. The accumulation of carbon elements on the outer tube surface appears to show significantly higher brittle zone in the outer tube and with the presence of tensile stress developed from operating thermal cycle which subsequently resulted in crack. It can be concluded that the water cooling pipe leakage was due to thermal fatigue.

Wide application prospects of graphene in the corrosion protection coatings field are owing to its excellent mechanical properties, outstanding chemical stability, corrosion resistance, and high corrosion resistance. Anti-corrosion composite was prepared using multilayer graphene powder as a filler and epoxy resin in this work to investigate the effect of graphene compositions in the zinc-rich epoxy (ZRE) as the modified anti-corrosion coating for carbon steel pipe. Using SEM for morphology along with the electrochemical performance was associated with changed content composite coating of graphene and pure epoxy resin coating. The measurement for open-circuit potential (OCP), the potentiostat polarization curve (Tafel Plot), and the electrochemical impedance spectroscopy (EIS) of the coating were conducted in order to investigate the influence of additional of graphene on the basic properties and corrosion resistance. From the experimental results, the increasing content of graphene led by the increasing value of OCP as the test system was stable, also the coating of high content graphene sustained a moderately high OCP ability with the increase of immersion time. From the results in the industrial environment, 0.1wt% Graphene + 99.9wt% ZRE in a 240μm coating layer would be sufficient as the corrosion rate is 0.0087204mmpy and three times lower compare to 100wt% ZRE. In a nutshell, the addition of graphene improves the impenetrability of the composite coating.

The paper deals with corrosion damage to steel pipes which were a part of the indirect cooling circuit of gas cleaning. The pipes were made from steel ASTM A106 Gr.B. The outer surface of pipes of the inside part of the circuit was affected by flue gases with mean temperature of approximately 1200 °C. The pipes of the outside part of the circuit were exposed to outer environment with mean temperature of about 25 °C. The cooling water flowing in these pipes had mean temperature of about 20 °C and contained a corrosion inhibitor based on zinc chloride (with addition of hydrochloric acid, phosphoric acid and PBTC). Flow rate of cooling water was 3700 m3/h, its total volume 1500 m3, and the pressure of cooling water was 600 kPa. The achieved thickening of cooling water was N=4. Side filtering was accomplished by a filter DPF 4000. The pipes of the cooling circuit were welded to each other, which initiated stress stimulating development of cracks on the outer surface of pipes in the heat-affected zone, Fig.1. The existing technological conditions resulted in formation of deposits on the outer pipe surfaces. Their presence changed thermal conditions in steel pipes.

Our study will be focused on stainless steel AISI 304—carbon steel ASTM A105 joints obtained by rotary friction welding and on their fatigue corrosion behavior in different testing environments. As a first thing, the joints will be characterized by microscopy and electrochemical techniques. The manuscript will then describe the optimization of the experimental setup and the validation of the testing procedure. After that, the fatigue behavior of the joints will be tested in different aggressive environments. This study pointed out that it is possible to build a simple and low-cost setup for the study of fatigue corrosion behavior of dissimilar joints while exploiting in situ electrochemical measurements to follow the fatigue corrosion process.

<p>Equipments used in industry process and migas is generally designed from alloy of steel which hold up to high temperature and attack corrosion. Based on that, it’s require to be conducted an material operation and election, like a component Boiler that is Secondary Superheater is generally weared by pipe from alloy of steel material Cr- Mo or steel with Austenitik type.<br />To know the damage of Secondary Superheater tube 2" material, can be conducted by a chemical composition analysis, test inspection metalografi and hardness. The damage of Material Secondary Superheater tube 2" at the extension las elbow in the form of rip on second potition (ASTM SA - 192) representing a militant low strength carbon material pipe, while on the first potition which there are not pipe material damage representing a militant high strength carbon (ASTM SA - 106 grade C) which a different thick each other. Attenuating showed the thick degradation which possible because of local stream turbulensi warm-up existence and which is high enough, this matter is shown with existence</p>

AgÃncia Nacional do PetrÃleo
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
Este trabalho teve como objetivo avaliar o comportamento das tensÃes residuais em tubulaÃÃes de aÃo ASTM A106 Gr. B com pequeno diÃmetro, soldada pelos processos TIG manual e automÃtico. Buscou-se tambÃm avaliar o efeito do aporte tÃrmico sobre o perfil de tensÃes, bem como correlacionar os resultados com a microestrutura e dureza. A mediÃÃo das tensÃes foi realizada atravÃs de difraÃÃo de raio-X, utilizando um minidifratÃmetro empregado para mediÃÃo em campo. AnÃlises metalogrÃficas foram realizadas na seÃÃo transversal da junta, atravÃs de microscopia Ãtica e microscopia eletrÃnica de varredura. Foram levantados os perfis de microdureza nas superfÃcies externa e interna. Os resultados mostraram que a mediÃÃo de tensÃes residuais por difraÃÃo de raio-X, usando o minidifratÃmetro para aplicaÃÃes em campo, à eficaz na determinaÃÃo do perfil de tensÃes, contudo, à necessÃria a realizaÃÃo de ajustes dos difratogramas por funÃÃes analÃticas, para determinar a correta localizaÃÃo do pico de difraÃÃo de raio-X, reduzindo o erro das medidas. As mediÃÃes das tensÃes residuais axiais realizadas na superfÃcie externa dos tubos mostraram que o perfil à formado por tensÃes compressivas na regiÃo da solda (zona fundida e zona afetada pelo calor) e por tensÃes trativas nas regiÃes mais afastadas. Foram observados elevados nÃveis de tensÃes residuais axiais compressivas na superfÃcie externa de tubos de parede fina, na regiÃo da solda, os quais podem representar uma situaÃÃo crÃtica, visto que o comportamento linear das tensÃes ao longo da espessura devido ao efeito torniquete à consensual e, portanto, isso indica a presenÃa de elevados nÃveis de tensÃes residuais de traÃÃo no metal de solda e na zona afetada pelo calor. O ciclo tÃrmico do passe de acabamento ocasionou um intenso refino de grÃo e uma significativa reduÃÃo de dureza, especialmente no metal de solda e na superfÃcie interna dos tubos, a exceÃÃo das amostras de 2â de diÃmetro soldadas com elevado aporte tÃrmico. Nenhuma das amostras soldadas apresentou valores de dureza acima do mÃximo estabelecido por norma, que à de 248 HV, mostrando que o fato da junta apresentar dureza baixa, nÃo necessariamente representa que esta nÃo esteja sujeita a um elevado nÃvel de tensÃes residuais.
The aim of this work was to evaluate the behavior of welding residual stress in small size pipes of ASTM A106 Gr. B steel, welded by manual and automatic GTAW processes. It was also evaluated the effect of the welding heat input on residual stress profile, as well as to correlate the results with microstructure and hardness. The residual stress measurement was accomplished through X-ray diffraction, using a minidiffractometer for measurement in field. Metallographics analysis were accomplished in the traverse section of the welded joint, using optic microscopy and scanning electron microscopy. The microhardness profiles in the outer and inner surfaces of pipe were determined. The results showed that the measures of residual stress by X-ray diffraction with minidiffractometer for applications in field was shown quite effective in the residual stress profile determination, however, it is necessary the accomplishment of diffractograms fittings by analytic functions, to determine the correct peak localization, reducing the measures error. The measurements of the axial residual stress accomplished in the outer surface pipes showed that the profile is formed by compressive stresses in the welds region (fusion zone and heat affected zone - HAZ) and for tension stresses in the areas more distant of weld bead. High levels of compressive axial residual stress were observed in the outer surface of small size pipes, located in the welds region, which can represent a critical situation, because the linear behavior of the through-thickness residual stress due to âtourniquetâ effect is consensual and, therefore, indicates the presence of high levels of tension residual stress in the inner surface, especially in the root weld metal and HAZ. The welding heat input of the finish pass caused an intense grain refining and a significant reduction of hardness of the weld metal in the inner surface, exception of 2" diameter sample welded with high heat input. None of the welded samples presented values of hardness above the maximum established for standard, which is 248 HV, showing that the fact of the welded joint to present low hardness, it does not necessarily represent that this is not subject to a high level of residual stress.

Steady-state operations are used globally in chemical engineering. Advantages include ease of control and a more uniform product quality (Ghasem and Henda, 2008; McCabe et al, 2001). Importantly however, there will be naturally occurring, random (stochastic) fluctuations in parameter values about the ‘set’ mean when process control is inadequate. These are not addressed explicitly in traditional chemical engineering because they are not sufficient on their own to be considered transient (unsteady) and because, generally, fluctuations in one parameter are off-set by changes in others with plant output behaviour seeming to remain steady (Amundson et al., 1980; Sinnott, 2005; Zou and Davey, 2016). Davey and co-workers, however, have demonstrated these fluctuations can unexpectedly accumulate in one direction and leverage significant (sudden and surprise) change in output behaviour with failure in product or plant (e.g. Abdul-Halim and Davey, 2016; Zou and Davey, 2016; Chandrakash and Davey, 2017). To underscore the unexpected element of the failure event they titled their risk framework Fr 13 2 (Friday 13th Syndrome). Case studies of their probabilistic risk framework to 1-step operations include loss of thermal efficiency in a coal-fired boiler (Davey, 2015 a) and failure to remove whey deposits in Clean-In-Place (CIP) milk processing (Davey et al., 2015). More recently, to advance their risk framework for progressively, multi-step and complex (in the sense of ‘integrated’, not ‘complicated’) processes they demonstrated its usefulness to 2-step membrane fouling with combined ultrafiltration-osmotic distillation (UF-OD) (Zou and Davey, 2016), and; a 3-step microbiological raw milk pasteurization (Chandrakash and Davey, 2017). Findings overall revealed no methodological complications in application - and it was concluded the risk framework was generalizable (Zou and Davey, 2016; Chandrakash and Davey, 2017). A significant advantage of the framework is it can be used in ‘second-tier studies’ to reduce risk through simulations of intervention strategies and re-design of physical plant or operating practice. It can be applied at both synthesis and analysis stages. 2 see Appendix A for a definition of some important terms used in this research. Although the risk framework has been successfully applied to corrosive pitting of AISI 316L metal widely used in off-shore oil and gas structures (Davey et al., 2016) 3 it was not known if it could provide new insight into corrosion of metal, more specifically microbiologically influenced corrosion (MIC), a major problem globally that accounts for ~ 20 % of overall corrosion (Flemming, 1996). It is estimated to cost AUD$7 billion to Australia annually (Javaherdashti and Raman-Singh, 2001). A review of the literature showed that a thorough understanding of MIC has been slow to emerge, both because of the role of micro-organisms in corrosion and because of a lack of methodology to determine any impact of natural fluctuations in the internal pipe environment. Importantly, the insidious nature of MIC was known to pose a practical risk of failure of pipes used to transport wet-fluids. However, because modelling of direct MIC would be uniquely complex it was planned that a general model for corrosion should be synthesized and understood that could be extended. A limited research program was therefore undertaken with the aim to advance the Fr 13 framework and to gain unique insight into how naturally occurring fluctuations in fluid temperature (T) and pH of the internal pipe environment can be transmitted and impact corrosion. A logical and stepwise approach was implemented as a research strategy. The initial model of Smith et al. (2011) was modified to simulate MIC causing micro-organisms such as sulphate-reducing bacteria (SRB) on widely used ASTM A105 carbon-steel pipe that is corroded under steady-state, abiotic and synthetic conditions. This was solved using traditional, deterministic simulations to give a predicted, underlying corrosion rate (CR) of 0.5 mm yr-1 as impacted by internal pipe-fluid T and pH. Importantly, findings underscored the controlling importance of low pH on CR. This initial model was then simulated, for the first time, using the probabilistic Fr 13 framework (Collins et al., 2016) 4 in which distributions to mimic fluctuations in T (K) and 3 This research was a Finalist, IChemE Global Awards 2016, Innovative Product, Manchester, UK, Nov. 4 Collins, S.D., Davey, K.R., Chu, J.Y.G., O’Neill, B.K., 2016. A new quantitative risk assessment of Microbiologically Influenced Corrosion (MIC) of carbon steel pipes used in chemical engineering. In: pH in the pipe were (reasonably) assumed as truncated Normal, and; a new corrosion risk factor (p) was synthesized such that all p > 0 characterized a CR failure i.e. a corrosion rate greater than 0.5 mm yr-1. Normal distributions that were truncated were used because these permitted T and pH to fluctuate randomly during process operations but limited these to values that could occur only practically. Predictions showed that 28.1 % of all corrosion of ASTM A105 pipe, averaged over the long term for a range of fluctuations 290.15 ≤ T ≤ 298.15 K, and 4.64 ≤ pH ≤ 5.67, would in fact be greater than the underlying value despite a design margin of safety (tolerance) of 50 % CR, and were therefore process failures (p > 0). Findings highlighted that corrosion was a combination of ‘successful’ and ‘failed’ operations. This insight is not available from traditional risk approaches, with or without sensitivity analyses. It was concluded that the Fr 13 framework was an advance over the traditional, deterministic methods because all corrosion scenarios that can practically exist are simulated. It was concluded also that if each simulation was (reasonably) thought of as one operational day, there would be (28.1/100 days × 365.25 days / year) ~103 corrosion failures in ASTM A105 pipe per year. However it was acknowledged that to enhance corrosion simulation, the free corrosion potential (Ecorr, V vs SCE), a key parameter in this initial model formulation, should more realistically be considered a combined function of the internal pipe-fluid T and pH, and; that this assumption should be tested, and, that this would necessitate a trial-and-error simulation for corrosion rate (CR). It was also determined that the truncations that were used for T and pH were too restrictive for off-shore oil processing (Arnold and Stewart, 1999; J. Y. G. Chu, Upstream Production Services Pty Ltd., Australia, pers. comm.). To address this, the initial model was extended mathematically for the first time, and; Fr 13 risk simulations carried out using spread-sheeting techniques utilizing the Solver CHEMECA 2016: Chemical Engineering – Regeneration, Recovery and Reinvention, Sept. 25-28, Adelaide, Australia, paper 3386601. ISBN: 9781922107831 function (Microsoft Excel™). A significant advantage was that the distributions defining the naturally occurring fluctuations in T and pH could be entered, viewed, copied, pasted and manipulated as Excel formulae. Predictions showed (Collins and Davey, 2018) 5 an underlying corrosion rate CR = 0.45 mm yr-1 – a change of approximately 10 % when the design margin of safety (tolerance) was reduced from 50 % to a more realistic 20 % for the improved model. This is significant because the tolerance of a model should be as low as can be accepted, as higher tolerances can infer that the process is safer than it actually is. Fr 13 simulations showed that 43.6 % of all corrosion of internal ASTM A105 pipe, averaged over the long term for a range of realistic fluctuations 282.55 ≤ T ≤ 423.75 K, and 4.12 ≤ pH ≤ 6.18 would be deemed to be process pipe-failures (p > 0). This translates to a corrosion failure in ASTM A105 pipe every 160 days, averaged over the long term. It is not expected that these would be equally spaced however. Findings were used in investigative ‘second-tier’ studies to explore possible intervention strategies to reduce vulnerability to corrosion and to improve plant design and safety. For example, repeat Fr 13 simulations revealed that, for a fixed mean-value of T = 353.15 K a decrease in pH from 5.15 to 4.5 resulted in an increase in carbon-steel pipe corrosion of ~1.55 mm yr-1 i.e. ~347 % increase. This implied that the pipe vulnerability to Fr 13 corrosion failure could be practically minimised by adding bases, such as potassium hydroxide or sodium carbonate (Kemmer, 1988). However, if the pH is too high, anions in the pipe-fluid could precipitate and form insoluble mineral scales, leading to fouling (Pichtel, 2016). It is acknowledged that the present research is limited to an abiotic system i.e. one without micro-organism kinetics. A justification is that the models presented in this research should be seen as a ‘starting point’, which could be expanded in later iterations to include: biotic model components such as the simple bacterial kinetics in the predictive MIC model of Maxwell and Campbell (2006); other species that are involved in MIC such 5 Collins, S.D., Davey, K.R., 2018. A novel Fr 13 risk assessment of corrosion of carbon-steel pipe in de-aerated water. Chemical Engineering Science – submitted CES-D-18-00449, Feb. as sulphates, chlorides and hydrogen sulphide (H2S); different metals/alloys that are used in pipe equipment where MIC can be found e.g. copper or zinc (Roberge, 2000), or; a ‘global’ model i.e. two or more connected unit-operations (Chandrakash and Davey, 2017). (A global model however, might not be applicable because MIC can be initiated in localized sites (Roberge, 2000)). It is concluded that these thesis findings nevertheless significantly enhance understanding of factors that lead to excessive corrosion rates in ASTM A105 pipes. It is concluded also that the Fr 13 risk framework appears generalizable to a range of micro-organism-metal systems and is an advancement over current existing risk and hazard assessments. If properly developed, it is thought that this risk technique could be adopted as a new design tool for steady-state unit-operations in both the design and synthesis stages and to increase understanding of MIC behaviour and outcomes. This research is original and not incremental work. Results and findings will be of immediate benefit and interest to a range of risk analysts, and to a broad range of practical operations involving carbon-steel pipe flows
Thesis (MPhil) -- University of Adelaide, School of Chemical Engineering & Advanced Materials, 2018

Abstract Carbon steel components (Flanges, Fittings and Piping) have been reported with low impact test results. Some have failed during hydrotest and start-up as well as in-service. Steel grades that have shown problems complying with impact test requirements are ASTM/ASME A105, ASTM/ASME A234 Gr. WPB and ASTM/ASME A106. ASTM A350 LF2. These components according to some design-fabrication industry standards are not suitable for use even though they complied with applicable ASTM/ASME materials standards meeting the mechanical properties and chemical composition. Some analyses have led to identify key contributing factors to this low impact test results including Chemistry/Micro-alloying, fabrication approach and use of 100% re-cycle steels. This paper presents summarize findings from numerous reports of failure, testing data and selected approach when screening these materials prior to installation. Based on literature review the need for improvement in the approach for mechanical testing including fracture toughness testing for modern materials was identified.

Brittle fractures in parent material carbon steel pipe, fittings, and flanges are surfacing in recent ASME B31.3 refinery and gas plant construction and facility start-ups with unexpected low toughness of 3J (2.2 ft-lb) to 7J (5.2 ft-lb) at −10°C (14°F) to −29°C (−20°F). The issue is becoming wide-spread globally, affecting up to 30 percent of materials tested, although many manufacturers are not experiencing this issue. The issue creates a new brittle fracture risk that needs to be addressed as the uncertainty of not knowing suitability for service at temperatures down to −29°C (−20°F) is concerning for reliability and safety. These components are considered by ASME VIII Div I and ASME B31.3 Code as being inherently ductile, and brittle fracture resistant without any Charpy impact testing requirements. Testing showed brittle transgranular cleavage cracks. The components were deemed to be unsuitable and not safe for use at low temperatures even though they complied with the applicable ASME Codes [1, 2] and ASTM material standards. Low toughness can result in brittle fracture of the material during hydrostatic tests, cold start-ups, or upset conditions that result in low temperature operations. Additionally, some ASTM A350 LF2 CL1 [3] forged flanges certified to −46°C (−50°F) exhibited the same 3J (2.2 ft-lb) to 7J (5.2 ft-lb) at −46°C (−50°F). This paper discusses historical literature, metallurgical investigations, findings, and factors that contribute to susceptibility to brittle fracture including chemistry, grain size, heat treatment and forming techniques and also issues of ductile to brittle temperature transition shift, and fracture mechanical assumptions. This paper provides guidance to ensure the components are suitable for service and proposes options in addition to the current minimum Codes requirements to mitigate risks of in-service brittle fracture.

Abstract Over the last decade, multiple carbon steel flanges brittle fracture failures have led the industry to issue a global alert on standard ASTM A105 flanges toughness values at temperatures higher than −20°F (−29°C), the minimum temperature allowed by the current editions of ASME B16.5 and ASME B31.3. The ASME BPV VIII Subgroup Toughness penalized these components by assigning the material the UCS-66 Curve A and modified UCS-66(c) to limit the minimum temperature of standard A105 flanges to 0°F (−18°C), unless the flanges have been normalized and manufactured to fine grain practice, after which they can be used down to the temperature permitted by ASME B16.5. In order to determine whether these changes would provide acceptable toughness values, nineteen (19) flanges were purchased from local manufacturers in both as-forged and normalized conditions and were subjected to several tests including charpy testing at various temperatures, McQuaid-Ehn, hardness testing, metallography, grain sizing, and chemical analysis. The results suggest that complying with UCS-66(c) does not necessarily guarantee acceptable toughness results for flanges that were normalized and manufactured to fine grain practice, and this is attributed to low Mn:C ratios and possibly uncontrolled heat treatment procedure. On the other hand, a number of non-normalized standard flanges have been found to provide very low toughness values at temperatures as high as 32°F (0°C), despite the current state of UCS-66(c) allowing use down to a minimum temperature of 0°F (−18°C). In view of the above, this paper discusses and evaluates some of the possible additional technical requirements that users could specify to minimize the risk of brittle fracture on standard ASTM A105 flanges, as well as a number of methods to guarantee better toughness performance in standard flanges.

Abstract This work presents an investigation of the ductile tearing properties for a girth weld made of an ASTM A106 Gr C steel using the SMAW welding process with a low hydrogen E7018 electrode thereby resulting in a weld with high strength overmatching with respect to the base material. Testing of the pipe girth welds employed side-grooved, clamped SE(T) specimens with a weld centerline notch to determine the crack growth resistance curves based upon the unloading compliance (UC) method using a single specimen technique. Recently developed compliance functions and η-factors applicable to weld centerline notched SE(T) specimens are introduced to determine crack growth resistance data from laboratory measurements of load-displacement records. While the UC procedure resulted in measured crack extensions for the tested specimens with weld centerline notch that underestimated the 9-point average crack extension, our preliminary results demonstrate the capability of the methodology in describing crack growth resistance behavior which serves as a basis for ductile tearing assessments in ECA procedures applicable to overmatched girth welds and similar structural components.

For corroded piping in low temperature systems, such as service water systems in nuclear power plants, replacement of carbon steel pipe with High Density Polyethylene pipe is a cost-effective solution. Polyethylene pipe can be installed at much lower labor costs than carbon steel pipe and High Density Polyethylene pipe has a much greater resistance to corrosion. Data was developed by the three testing tasks for use in the seismic design of above ground High Density Polyethylene Piping systems. This paper presents the results of testing to determine the relationship between tensile elastic modulus and strain rates commensurate with seismic loading. This is accomplished by first establishing a seismic strain rate for High Density Polyethlene using detailed finite element analysis. The results of this analysis are used to establish a test matrix tensile testing. Next, tensile tests are conducted using standard ASTM D-638 Type III tensile specimens. The tensile testing is conducted at three pull speeds to establish a basic relationship between tensile elastic modulus and strain rates. This relationship is then used to calculate the modulus at the strain rates expected under seismic loading. This paper presents the results of this testing and the suggested tensile modulus for use in seismic analysis.

Fitness-for-service (FFS) assessments are quantitative engineering evaluations that perform to demonstrate the integrity of an in-service component that may contain a flaw or damage [1]. It can be used to make run-repair-replace decisions to help determine if pressured equipment containing flaw that have been identified by inspection can continue to operate safety for some period of time. This paper provides a FFS assessment on carbon steel pipe which contained a LTA (Local Thin Area) against seismic load by FEM (Finite Element Method) analysis. ABAQUS Ver. 6.10, which has the combined isotropic / kinematic hardening model [2], is used to simulate the LTA contained carbon steel pipe against seismic load. Material parameters in the hardening model are identified by a symmetric strain cycle experiment based on ASTM E606. Isotropic hardening component is introduced by specifying the equivalent stress defining the size of the yield surface, as a tabular function of the equivalent plastic strain. Kinematic hardening component is obtained from the stabilized cycle of a specimen that is subjected to symmetric stain cycles. The authors introduced the way how to calibrate the material parameters of combined isotropic / kinematic hardening model. Then the authors calculated up to 100 cycles on carbon steel pipe which contained a Local Thin Area against seismic load at 300 degrees centigrade. The results comparison between FEM analysis and experiment shows that stress-strain hysteresis loop tendency and number of cycles to failure are predicted accurately.

Abstract The technology to cost effectively design, construct, operate, and maintain ASTM A269 TP316L/TP316 stainless-steel pipelines for oilfield saltwater service and freshwater service was developed between 2002 and 2004. The first installations were austenitic pipe installed within discontinued, corroded carbon steel pipelines. Primary goals were to identify a cost-effective solution for a pipe-in-pipe application. After 2004, free-standing austenitic pipeline were installed in trenches. It was determined that coils of 316L/316 tubing in lengths of 2000 meters (6500 feet) were cost effective and readily available as line pipe material to simplify the field installation and joining practices. It was also determined that internal coatings, external coatings, and cathodic protection (except for risers) were not required for corrosion protection. Highlights from the engineering assessments and the examination of 17 cut-out samples of in-service piping will be presented to demonstrate the suitability of 316L/316 for oilfield water applications. Boundary limitations for temperature, transported fluid composition, and soil composition were defined to ensure that corrosion and stress corrosion cracking would not occur. Mechanical design and joining methods and concepts were adopted from ASME B31.3 because existing pipeline codes (e.g. CSA Z662) did not, and currently do not address this material for oilfield pipelines. Between 2002 and 2010, 90 pipelines for freshwater service and 55 pipelines for saltwater service were installed. A review in 2021 indicated that none of the installed pipelines have experienced leaks or failures associated due to in-service degradation. Two leaks have occurred during this 19-year period; one leak was attributed to installation wear and one leak was attributed to poor installation of a mechanical fitting. Material suitability was also verified via examination of cut-out pipe/fitting samples, and the use of stainless-steel corrosion coupons for 13 years. A comparison to other materials of construction indicates that the 316L/316 pipelines performed better. This case history will address the successful design, construction, operation, and maintenance of austenitic stainless-steel pipelines during the 2002 to 2021 period.

UK very high integrity (VHI) component classification includes design, manufacturing, and inspection requirements that go beyond those established in ASME BPVC Sec. III Subsection NB [1]. One of these requirements is to ensure the component is tolerant of manufacturing defects. This can be demonstrated using a Defect Tolerance Assessment (DTA) based on two parameters fracture mechanics method. The brittle fracture parameter of this assessment requires the analysis of stress occurring in the component against the plane strain fracture toughness, KIC of the material. This work focuses on the practical determination of KIC for materials chosen for a Boiling Water Reactor (BWR) Main Steam Piping (MSP) and Main Steam Isolation Valve (MSIV), which carbon steel seamless pipe SA-106 Grade C and carbon steel casting SA-216 Grade WCB, are respectively. These materials are usually tested by Charpy impact testing specified in [1], but there are not many studies reporting their KIC, and there is not enough information concerning actual piping and valve materials. Thus the authors implemented fracture toughness testing using J-resistance curve according to ASTM E 1820 [2] for test pipe and test casting block simulating actual MS Piping and MSIV, and evaluated KIC(J) to be used in DTA. KIC(J) is evaluated from elastic-plastic fracture toughness, JIC, gained from the J-resistance curve, and equivalent to KIC [3]. KIC(J) corresponds to KJIc in ASTM E 1820. There were some cases, however, in which valid JIC values could not obtained, because of the materials high toughness, test specimen size limitations, and uneven final crack sizes. When valid JIC can’t be obtained, retesting or remanufacturing would significantly affect plant construction schedule. Hence, alternative evaluation methods by which JIC can certainly be obtained are desired. In this study, the authors focused on two types of alternative JIC evaluation methods. The first one is the Stretch Zone Width (SZW) method, in which JIC is calculated from SZW measurements of crack tip plastic blunting on fracture toughness test specimens. The SZW method was well studied in the 1970s, and experimental data showed a clear correlation between JIC values obtained from J-resistance curves and JIC values obtained from SZW measurements [4]. The second method is by correlation of JIC with the energy absorbed during Charpy testing. As represented by Rolf’s study [5], it has been reported that there are correlations between Charpy absorbed energy and KIC for high tensile strength steels. In this study, the validity of the SZW method was first evaluated by comparing its results with JIC obtained from J-resistance curves. Then, the applicability of the JIC values to DTA of actual products was discussed. Finally, by comparing Charpy absorbed energy and KIC(J), the validity and applicability of KIC determination method with Charpy absorbed energy was discussed.

For corroded piping in low temperature systems replacement of buried carbon steel pipe with high density polyethylene (HDPE) pipe is a cost-effective solution. The ASME Boiler and Pressure Vessel Code, Section III, Division 1, Code Case N755-1 currently permits the use of HDPE in buried Safety Class 3 piping systems. This paper presents the results of tensile testing of PE 4710 cell classification 445574C pipe compliant with the requirements of Code Case N755-1. This information was developed to support and provide a strong technical basis for tensile properties of HDPE pipe. The data may also be useful for applications of HDPE pipe in commercial electric power generation facilities and chemical, process, and waste water plants via its possible use in the B31 series piping codes. The paper provides values for yield stress, yield strain, ultimate strain, and elastic modulus. The standard tensile tests were conducted consistent with the requirements of ASTM D638-10. Specimens were cut in the axial direction from cell composition PE 4710 cell classification 445574C HDPE piping spools. In addition, the results are compared to previous tensile testing conducted on the PE 3608 cell classification 345464C and PE 4710 cell classification 445474C HDPE materials.

The current Leak Before Break (LBB) assessment is based primarily on the monotonic fracture tearing instability. In it the maximum design accident load is compared with the fracture-tearing resistance load. The effect of cyclic loading has generally not been considered in the fracture assessment of nuclear power plant piping. It is a well-known fact that the reversible cyclic loading decreases the fracture resistance of the material, which leads to increased crack growth. Indian nuclear power reactors consider Operational-Basis-Earthquake (OBE) and Safe-Shutdown-Earthquake (SSE) event in the design of various structures, systems and components. Keeping this in view a series of cyclic tearing test have been conducted on straight pipes, made of ASTM SA333 Gr.6 carbon steel. This is the material of primary heat transport (PHT) piping material of Indian Pressurised Heavy Water Reactor (PHWR). In this series 13 tests have been carried out on circumferentially through wall cracked seamless and circumferential seam welded straight pipes under reversible cyclic bending loading. All the tests have been conducted under quasi-static i.e. slow loading rates and the dynamic effect is not considered. The cyclic test results have been compared with the corresponding monotonic pipe fracture test results. These test results and its comparison with corresponding monotonic tearing clearly illustrates the need of addressing the reduction in apparent fracture toughness of material under reversible cyclic loading and safe number of load cycles in the LBB assessment.