Concepts and Production Results of Heavy Wall Linepipe in Grades up to X 70 for Sour Service

Author(s):  
Andreas Liessem ◽  
Volker Schwinn ◽  
Jean-Pierre Jansen ◽  
Rolf K. Poepperling

This paper summarizes the main mechanism and influencing factors for Hydrogen Induced Cracking. The evolution of HIC test requirements over nearly 30 years for linepipe intended for sour service are reviewed. Some typical examples of the requirements for sour service pipe production at Europipe (formerly Mannesmann) developed over the past 20 years and the details of trial production of sour service pipes in grade X 70 with 30 mm wall thickness are presented. However, with the steadily increasing demands it becomes progressively more difficult to fulfill the before mentioned standard test conditions. In those cases where the overall profile of requirements (strength, toughness) can not be consistently achieved, fit-for-purpose testing methods are currently emerging. As an example the results of a pipe order, where the fit-for-purpose approach has been used to qualify the pipe for a special project, will be described.

Author(s):  
Kristine Severson ◽  
A. Benjamin Perlman ◽  
Michelle Muhlanger ◽  
Richard Stringfellow

Investigations of passenger train accidents have revealed serious safety hazards associated with the thin, rigid tops of workstation tables, which are common fixtures aboard rail cars. Thoracic and abdominal injuries caused by occupant impact with workstation tables have been cited as the likely cause of two fatalities during a 2002 accident in Placentia, CA [1]. Additionally, workstation tables have been cited as the cause of injury in reports on accidents in Intercession City, FL [2], and Burbank, CA [3]. Currently there are no regulations or safety standards governing the crashworthiness of tables in passenger trains beyond attachment strength requirements. However, research sponsored by the Federal Railroad Administration (FRA) and in collaboration with the American Public Transportation Association (APTA) Passenger Rail Equipment Safety Standards (PRESS) Construction & Structural working group is underway to develop a mandatory industry safety standard for tables to ensure that they will be designed to provide a minimum level of safety during a train accident. FRA’s Equipment Safety Research Program has already developed and tested a prototype table design to demonstrate the improved occupant protection provided by an energy-absorbing table. The prototype table design was tested using a THOR [4] and an H3RS [5], which are advanced anthropomorphic test devices (ATDs), onboard a 35 mph full-scale train-to-train impact test of rail cars modified to incorporate crash energy management (CEM) [6]. Test results demonstrated that the Injury Assessment Reference Values (IARVs) measured by the instrumented ATDs were within human tolerance levels established by the National Highway Traffic Safety Administration (NHTSA) for automotive crashworthiness for the head, neck, chest, abdomen, and femur. Having demonstrated the effectiveness of an energy-absorbing table, the next step is developing a performance-based safety standard for tables that ensures a minimum level of crashworthiness. The safety standard would employ the use of an 8G dynamic sled test with instrumented ATDs to evaluate occupant injury and structural integrity of the table, similar to the seat test requirements in APTA-SS-C&S-016-99 [7], which is the industry safety standard for passenger seats in rail cars. Normally, advanced ATDs like the THOR would be required to measure abdominal and thoracic loads caused by the table impact during the sled test. However, use of these experimental ATDs for table qualification testing is not feasible due to their limited availability. Therefore, alternative test methods must be developed to evaluate the crashworthiness of workstation tables. This paper evaluates several potential methods to measure table crashworthiness, including quasi-static crush testing, pendulum impact testing, drop tower testing, and sled testing with standard Hybrid III 50th percentile ATDs. The pros and cons of these tests are also described. After evaluating the various testing methods, test conditions for two separate tests are proposed for an industry table standard. A companion paper [8] describes analysis results used to establish performance requirements proposed for evaluating table crashworthiness for the safety standard, in accordance with the test conditions proposed in this paper.


Author(s):  
M. Elboujdaini ◽  
R. W. Revie

The demand for steel for the production of pipelines to transport gas and oil containing hydrogen sulphide prompted the development of steel that is resistant to hydrogen induced cracking (HIC). During the past two decades, combined research efforts in the areas of product and process metallurgy have made it possible to satisfy most of the main requirements for grades X-42 and X-60 microalloyed steel for mildly acidic (pH = 5) H2S environments. Building on the experience acquired in the area of microalloyed steel for a mildly acidic (pH ∼ 5) H2S environment, the industry launched a program to develop steel that would satisfy new requirements for H2S-resistant pipelines under NACE conditions (TM0177, pH∼3). In order to develop these steels, it was necessary to define qualitatively and quantitatively the specific effects on H2S resistance of the multiple intrinsic parameters of the product itself as well as those resulting from the process. In this paper, data will be presented that have made it possible to relate the HIC performance of steels to chemical content, inclusion levels and thermomechanical treatment parameters.


1929 ◽  
Vol 2 (3) ◽  
pp. 406-408 ◽  
Author(s):  
R. P. Dinsmore

Abstract In various papers, published in the past three years, E. C. Zimmerman and the writer have made references to the variability of crude rubber as determined by the properties of vulcanized compounds of various types. We were, I believe, the first to point out the chief stumbling block in the way of establishing a standard test formula for evaluating crude rubber, namely the variation in both quality and rate of cure produced by curing the same rubber with different curing agents. At the outset we were confronted with difficulties which resulted from a deplorable lack of standardization of rubber testing methods, and more specifically from a lack of agreement as to the proper way to select comparable cures. Indeed, it is obvious that these drawbacks have been among the major causes for lack of correlation of available data on the subject. We have stressed the importance of considering those properties of the vulcanizate which are reflected in the performance of the finished product, and have stated our objections to many of the popular criteria, such as “slope,” tensile product, tensile, and coefficient of vulcanization. We had concluded that aging should be the chief criterion of best technical cure. Accelerated age tests cannot be relied upon for comparison of different mixes, but experience has shown that for lightly loaded mixes hand tear is a reliable method of fixing the best aging cure. With this as a means of selecting the time of cure, the quality was studied by comparing the stiffness of the stress-strain curve at best cure. Later, in a paper on acceleration classification, if was shown that these conclusions might properly be modified when dealing with loaded mixes. Here the cures, as selected by hand tear and by maximum, tensile product, were in substantial agreement, except in the case of non-accelerated stocks.


Author(s):  
Djordje Mirković ◽  
Volker Flaxa ◽  
Franz Martin Knoop

Within the corresponding commercial and R&D projects five microalloyed pipeline steel grades have recently been developed and processed to spiral-welded pipes. For steel grades X52, X65, and X70 the aimed tensile properties, improved sour service resistivity, and low temperature toughness up to −40°C were reliably achieved. Influence of steel cleanliness, the non-metallic inclusions in particular, on sour gas resistibility has been investigated by means of ultrasonic testing of hydrogen charged HIC (Hydrogen Induced Cracking) samples and SEM (Scanning Electron Microscope) analyses of HIC fracture surfaces. The results have been used to optimize the applied process parameter in steel production and coil processing. The ladle metallurgical treatment and soft reduction were consistently applied within narrow process tolerances enabling high steel cleanness and slab centerline quality, which are both indispensable for sour service application. Subsequent TMCP (Thermo Mechanical Processing) wide strip hot rolling and cooling parameters were selected to prevent a two-phase finish rolling and to obtain a predominating acicular ferritic microstructure. For pipe production, attention was paid to minimize the residual stresses, due to both pipe-forming and welding. The alloying approach is based on the classical sour lean NbTi steel composition, modified by varying Cu, Ni, Cr, and Mo contents to achieve the targeted specification. The processed spiral-welded pipes were formed to diameters between 762 and 1372 mm with a wall thickness of 13.7 to 16.0 mm. CVN (Charpy V-Notch) values were higher than 360 J/cm2 and DWTT (Drop Weight Tear Test) higher than 60% SA (Shear Area) at −40°C. The samples also showed outstanding HIC resistivity. Being proved with standard test conditions according to NACE TM0284 solution A, the CAR (Crack Area Ratio) average value of pipe samples was less than 1% for grades up to X65 and less than 5% for X70 grades. The 4-point-bending SSC (Sulphide Stress Cracking) tests at 80% of SMYS according to NACE TM0177 and ASTM G39 showed no SSC cracks for all projects. Finally, the results of one specific R&D project are presented to demonstrate that even for API X70 grade spiral-welded pipes (OD 1016×16 mm) mechanical properties, e.g. high-strength, ductility, and low temperature toughness has been successfully combined with sour service resistivity.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Fin O’Flaherty ◽  
Fathi Al-Shawi

AbstractThis study presents a detailed analysis of the lateral forces generated as a result of vertically applied loads to recycled plastic drainage kerbs. These kerbs are a relatively new addition to road infrastructure projects. When concrete is used to form road drainage kerbs, its deformation is minimum when stressed under heavy axle loads. Although recycled plastic kerbs are more environmentally friendly as a construction product, they are less stiff than concrete and tend to deform more under loading leading to a bursting type, lateral force being applied to the haunch materials, the magnitude of which is unknown. A method is proposed for establishing the distribution of these lateral forces resulting from deformation under laboratory test conditions. A load of 400 kN is applied onto a total of six typical kerbs in the laboratory in accordance with the test standard. The drainage kerbs are surrounded with 150 mm of concrete to the front and rear haunch and underneath as is normal during installation. The lateral forces exerted on the concrete surround as a result of deformation of the plastic kerbs are determined via a strain measuring device. Analysis of the test data allows the magnitude of the lateral forces to the surrounding media to be determined and, thereby, ensuring the haunch materials are not over-stressed as a result. The proposed test methodology and subsequent analysis allows for an important laboratory-based assessment of any typical recycled plastic drainage kerbs to be conducted to ensure they are fit-for-purpose in the field.


2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Vandana Jha ◽  
Uday Shankar Triar

This paper proposes an improved generalized method for evaluation of parameters, modeling, and simulation of photovoltaic modules. A new concept “Level of Improvement” has been proposed for evaluating unknown parameters of the nonlinear I-V equation of the single-diode model of PV module at any environmental condition, taking the manufacturer-specified data at Standard Test Conditions as inputs. The main contribution of the new concept is the improvement in the accuracy of values of evaluated parameters up to various levels and is based on mathematical equations of PV modules. The proposed evaluating method is implemented by MATLAB programming and, for demonstration, by using the values of parameters of the I-V equation obtained from programming results, a PV module model is build with MATLAB. The parameters evaluated by the proposed technique are validated with the datasheet values of six different commercially available PV modules (thin film, monocrystalline, and polycrystalline) at Standard Test Conditions and Nominal Operating Cell Temperature Conditions. The module output characteristics generated by the proposed method are validated with experimental data of FS-270 PV module. The effects of variation of ideality factor and resistances on output characteristics are also studied. The superiority of the proposed technique is proved.


Author(s):  
Rizal Razman ◽  
Ryan Wy Lunn Chong

The Protector and Scoring System was introduced in taekwondo to encourage transparency in scoring during competition. The system, which has been used in the past two Olympics, consists of two main components, the electronic body protector and socks. The few studies that have been conducted on the Protector and Scoring System have not been comprehensive and used questionable testing methods. The main objectives of this study were to methodologically examine the validity and reliability of a Protector and Scoring System body protector. To fulfil these objectives, a customized mechanical pendulum was built to test the Protector and Scoring System. The reliability of the pendulum was first determined by tracking the pendulum’s mean velocity at impact for 50 trials on two separate occasions. Data from both days were compared and showed no significant differences ( p = 0.08). Mean kinetic energy of the pendulum was then calculated to be 55.52 J. For the experimental trial, the electronic body protector was divided into 12 sections. Each section was tested with the pendulum for 50 trials on two separate days. It was found that only three sections had no significant differences between the two days ( p > 0.01), while the rest of the sections had significantly different readings between Day 1 and Day 2. Based on the homologous descriptive statistics, only two sections were in the same group, which translated to the Protector and Scoring System being only 16.7% reliable overall for both days. In terms of validity, an independent samples t-test was used to determine the differences between the calculated kinetic energy from the pendulum (the criterion) and the displayed kinetic energy on the Protector and Scoring System, and values were found to be significantly different ( p < 0.01). Overall, the reliability and validity of the Protector and Scoring System was found to be questionable. The system needs to be examined exhaustively before being used in any future tournaments.


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