|
| 3R international 07 / 2003 | 89 Seite(n) |
Zeitrschrift für Rohrleitungspraxis
Vulkan Verlag
|
Leserecht ab 2.69 EUR
pro Kapitel |
Gleich lesen
|
|
Druckrecht 1.35 EUR pro Seite Kopierrecht 1.35 EUR pro Seite
|
|
|
|
|
|
|
|
|
| |
Ausschnitt aus dem Kapitel: High-strength large-diameter pipe for long- distance high pressure gas pipelines
|
| |
|
« Zurück zu Artikelübesicht
| Ausschnitt aus der Seite 48 |
komplette Inhalt der Seite 48 » |
| Bitte beachten Sie, daß der Inhalt dieser Seite kostenpflichtig ist. Der Text auf dieser Seite ist nach dem Zufallsprinzip strukturiert. Um den tatsächlichen Wortlaut zu erhalten, folgen Sie bitte diesem Link oder wiederholen Sie hier Ihre Suchanfrage gezielt in unserem Archiv. |
|
| darstellen. Deshalb werden die Vorteile, die durch den Gebrauch von hochfesten Leitungsrohren entstehen, und die heutigen technischen Begrenzungen bei der 482 3R international (42) Heft 7/2003 Highstrength largediameter pipe for longdistance high pressure gas pipelines Hochfeste Großrohre für HochdruckGasfernleitungen The kurt.niederhoff@mfi.de Dr.Ing. Michael K. Gräf Europipe GmbH, Mülheim (G) Tel. 49(0)208/4584026 EMail: michael.graef@europipe.com Dr.Ing. HansGeorg Hillenbrand Europipe GmbH, Ratingen (G) to end users. The energy scenario has been changing quickly in recent years. International studies forecast that the demand for of using highstrength linepipe and the presentday technical limitations on its production are addressed. Laboratory and production results on highstrength % compared with grade X 80 pipeline. This study claims cost savings of up to 30 % when X 70 This wi make the high pressure natural gas transportation via pipelines increasingly interesting. The use of grade X 80 linepipe Tel. 49(0)2102/857135 EMail: hansgeorg.hillenbrand@rgt.europipe.com Tests gezeigt, die an X 80 Produktionsrohrgüten durchgeführt wurden, die bei Onund OffshoreProjekten eingesetzt wurden. Der wirtschaftliche Gastransport über sehr largediameter pipes are presented to describe the materials properties as well as the service behaviour. Girth welding procedures covering mechanised Produktion dieser Leitungsrohren angesprochen. Gezeigt werden Laborund Produktionsergebnisse von hochfesten Rohren mit großen Nennweiten, um sowohl die Materialeigenschaften als auch need for the construction of complex gas transportation pipeline networks, when the use of LNG tankers is impossible or uneconomical. and manual methods have already been developed. Die stets wachsende Nachfrage an Erdgas wird auch weiterhin die Art des Transports das Betriebsverhalten zu beschreiben. Umfangsschweißverfahren, die mechanische und manuelle Methoden umfassen, sind bereits entwickelt worden. Introduction This paper gives an and the benefits of using X 80 pipe are presented. Also, important aspects of the properties of base material and wirtschaftliche Art, Gas von der Produktionsstätte zu den Endverbrauchern zu transportieren. Der Energiesektor hat sich in den letzten Jahren schnell has already been shown to result in substantial cost savings. Results of tests on grade X 80 production pipe supplied could lead to further material savings in terms of reduction of wall thickness as it is illustrated in Figure 1. everincreasing demand for natural gas will further influence the type of its transportation in the future, both from the strategic for onshore and offshore projects are presented in this paper. But the economic transport of gas over very long distances challenges and opportunities in the future. Special attention is focused on the effect of boron on the mechanical properties of sich gezeigt, dass der Gebrauch von X 80 Rohrleitungsgüten zu substantiellen Kostenersparnissen führt. In diesem Beitrag werden die Ergebnisse von pipelaying costs. The use of grade X 80 line pipe in the construction of the first Ruhrgas X 80 pipeline of the pipelaying costs because of reduced pipe transportation costs and greatly reduced welding costs through reduced welding times needed Einsatz von Flüssiggastankern unmöglich oder unwirtschaftlich ist. Dies wird den Hochdrucktransport von Erdgas mittels Rohleitungen verstärkt interessant machen. Es hat that can be derived by using highstrength steels [1], even when the price per tonne of the pipe increases as natural gas will be nearly doubled by 2030. The distance between gas production sites and end users increases, implying the wall thickness from 20.8 mm for X 70 to 18.3 mm for X 80. This resulted also in a reduction and X 100 are compared. Given that, in a complex pipeline network operating at high pressure, the capital expenditure is very high, it becomes understandable how much more attractive the high strength steel option could be. Dipl.Ing. Carl J. Heckmann overview of the development of highstrength lowalloy linepipe grades. Some of the current projects for pipelines in grade X 80 are dealt with. Project Cost Reduction Project cost reduction may be a result of the sum of the different benefits und den Endverbrauchern nimmt zu und beinhaltet die Notwendigkeit für die Errichtung eines komplexen Rohrleitungsnetzwerkes für den Gastransport, wenn der the material grades between > X 80 and X 120. Furthermore, the various aspects of production welds and field weldability A preliminary economic evaluation [2] highlighted that high pressure X 100 pipelines could give investment cost savings of about 7 für Erdgas, sowohl von einem strategischen als auch von einem wirtschaftlichen Standpunkt aus betrachtet, beeinflussen. Fernleitungen sind eine sichere und Mannesmann Forschungsinstitut, Duisburg (G) Tel. 49(0)203/9993235 EMail: carl.heckmann@mfi.de FACHBERICHTE Dr.Ing. Kurt A. Niederhoff Mannesmann Forschungsinstitut, Duisburg (G) Tel. 49(0)203/9993111 EMail: requires additional cost cuts. The use of grade X 100 and/or X 120 could be a solution. Therefore, the benefits led to a material saving of about 20000 t, compared with grade X 70 pipes, through a reduction of the gewandelt. Internationale Studien prognostizieren, dass sich die Nachfrage an Erdgas bis 2030 fast verdoppeln wird. Die Entfernung zwischen den Gasproduktionsstätten welds are discussed. The development of material grades up to X 100 or X 120 represents one of the big the material grade increases. The benefits include: n reduced quantity of steel required n lower pipe transportation costs n lower with thinner walls. The use of materials with sti higher strength, such as grade X 100 or grade X 120 and economic point of view. Longdistance pipelines are a safe and economic means to transport the gas from production sites lange Distanzen erfordert aber auch zusätzliche Kostenreduzierungen. Eine Lösung könnte der Gebrauch von den Güten X 100 und/oder X 120 |
| |
|
« Zurück zu Artikelübesicht
| Ausschnitt aus der Seite 49 |
komplette Inhalt der Seite 49 » |
| Bitte beachten Sie, daß der Inhalt dieser Seite kostenpflichtig ist. Der Text auf dieser Seite ist nach dem Zufallsprinzip strukturiert. Um den tatsächlichen Wortlaut zu erhalten, folgen Sie bitte diesem Link oder wiederholen Sie hier Ihre Suchanfrage gezielt in unserem Archiv. |
|
| 483 3R international (42) Heft 7/2003 FACHBERICHTE On the other hand, it becomes clear from Figure 1 that the reduction konstanten Transportkapazität benutzt werden Tabel le 1 : Europipe Projects executed with line pipes made of grade X 80 Tab l ine ll lengtt th 1984 MEGAL 44 x 13.6 mm 3.2 km 1985 CSSR 56 x 15.5 mm 1.5 the steel is processed to plate by thermomechanical rolling plus modified accelerated cooling. The development of high strength steel for thickness and the necessary induction bends. Since the strength decreases as the wall thickness increases, it had been necessary at Additions of molybdenum, copper and nickel enable the strength level to be raised to that of grade X 100, when km 1991/92 Ruhrgas 48 x 18.3 mm 250 km 200103 Transco 48 x 15.1 mm 158 52 km 2001/03 CNLR that time to raise the carbon and manganese levels marginally. The concentrations of all other elements remained unchanged. Fig . 80 line pipe installed, for the first time in history, in the Megal II pipeline. A manganeseniobiumtitanium steel, additionally alloyed of the production parameters enabled the CSSR order to be executed using a manganeseniobiumtitanium steel without the additions of copper a more favourable solution to the problem. Development of HighStrength Steel Grades The improved processing method for currently used highstrength 24 x 25.4 mm 13 km Fig . 2 : View of a pipelaying operation (Transco project) B i ld extensive work to develop highstrength steels in grades X 80 and X 100 to assist customers in their endeavour to it has become possible to produce highstrength NbTi microalloyed material, having a reduced carbon content and thereby excellent field weldability. From the point of view of pipe manufacturers, reduction of pipe wall thickness is not a preferred option. A reduction and nickel. The first pipeline using GRS 550 (X 80) for its entire length of 250 km was the Ruhrgas pipes in grade X 120 consists of further optimisation of the thermomechanical treatment and the use of niobium, titanium and boron as microalloying elements. First results of this development as regards the mechanical properties of the new material are very WernetoSchlüchtern pipeline project implemented in Germany in 1992. Europipe supplied all 48” diameter pipe with up to 19.3 mm wall . 1 : EuropipeProjekte, die mit Leitungsrohren aus X 80 ausgeführt wurden Year Order P ipe geomett try P ipell in the manufacturing cost per tonne of the pipe at a given transport capacity of a pipeline is enhanced not with copper and nickel, was used for the production of the 44” OD x 13.6 mm WT pipe. Subsequent optimisation in pipe diameter at constant pipe thickness and a simultaneous increase in pipeline operating pressure would represent, in our opinion, reduce pipe weight and pipelaying costs. Since 1984 longitudinal seam submergedarc welded grade X 80 pipe has been used in 1 : Manufacturing cost per tonne of pipe for different steel grades and wall thicknesses to be used at a steels like X80 and higher, consists of thermomechanical rolling (emerged in the 1980s) followed by accelerated cooling. By this method, encouraging. Grade X 80 X 80 Projects and relevant pipe properties In the past two decades, Europipe has carried out constant transportation capacity B i ld 1 : Produktionskosten je t Rohr für verschiedene Stahlgüten und Wanddicken, die bei einer just by the increase in the material grade of the steel but also by the reduction in pipe wall thickness. 2 : Ansicht eines Rohrverlegungsvorgangs (TranscoProjekt) the implementation of several pipeline projects in Europe and North America (Tabe 1). In 1984, Europipe produced the grade X |
| |
|
« Zurück zu Artikelübesicht
| Ausschnitt aus der Seite 50 |
komplette Inhalt der Seite 50 » |
| Bitte beachten Sie, daß der Inhalt dieser Seite kostenpflichtig ist. Der Text auf dieser Seite ist nach dem Zufallsprinzip strukturiert. Um den tatsächlichen Wortlaut zu erhalten, folgen Sie bitte diesem Link oder wiederholen Sie hier Ihre Suchanfrage gezielt in unserem Archiv. |
|
| impact tests performed were within the specification for grade X 80. The standard deviation was 15 MPa for the yield Nova 0.9 Ar/CO2 75/25 190/220 19/21 75 n Hot Pass Thyssen NiMo 80 0.9 CO2 240/260 24/26 127 n Filler recent Transco projects. Tabe 2 describes a welding procedure applied to X 80 pipes. Figure 5 shows the mechanical properties rolling conditions. Approach A, which employs a high carbon equivalent, at 0.49, has the disadvantage that the crack arrest toughness To cope with the market requirements for enhanced pipe strength, Europipe put its effort to the development of grade X of the Transco pipeline construction site. After finishing welding, non destructive examination and field joint coating, the girth welded pipeline requirements in all cases. The standard deviation for the yield and tensile strength values was very low. The impact energy . 4 : Toughness properties of Transco grade X 80 pipe (48” OD x 15.1 mm WT) B i ld % shear area transition temperatures determined in the drop weight tear (DWT) tests were far below 0 °C. In 2001, plate or pipe was obviously not necessary. Since 1995, Europipe has developed different approaches to produce high strength materials [1]. ] Osc i la t ion Trade name d ia [mm] Sh ie ld ing Gas Root Pass Thyssen K 354 °C. The high temperature properties were determined and found satisfactory. For a new hot steam pipeline section, further 7.7 the context of certification of the pipe are shown in Figure 3 and 4. All results of the tensile and 15.1 mm WT) B i ld 3 : Zugspannungseigenschaften des TranscoRöhrenstahl X 80 (48 AD x 15,1 mm WD) Fig detrimental, e.g. to field weldability. Fig . 3 : Tensile properties of Transco grade X 80 pipe (48” OD x 26/41 y As can be seen in Figure 6, three different approaches are generally possible in selecting the chemical composition and plate with narrow gaps. Narrow gaps require a reduced number of individual passes. One of the very efficient automatic GMA welding properties are not good and therefore requirements to prevent longrunning cracks may not be fulfilled. Moreover, this approach is also base metal and 134 J for weld metal. One of the most challenging projects encountered in 2001 was a hot manual SMAW and automatic GMAM. These welding methods are wellestablished now and regarded as sufficiently validated for largescale use [4 Passes Thyssen NiMo 80 0.9 CO2 210/250 22/25 36/45 y Cap Pass Thyssen NiMo 80 0.9 Ar/CO2 75/25 200230 20/22 4 : Härteeigenschaften der TranscoRöhrenstahl X 80 (48 AD x 15,1 mm WD) Tabe 2 : Typical welding parameters for values measured on Charpy Vnotch impact specimens at 0 °C was very high, averaging to about 180 J. The 85 strength values and 13 MPa for the tensile strength values. The average value of impact energy was 227 J for 2002 and 2003, X 80 (L555MB) pipes were manufactured again for Transco projects in the UK. Linepipe for several parts steam system for CNRL in Canada [3]. The longitudinally welded line pipe was qualified for use at temperatures up to GMAW of grade X 80 by the CRC process Tab . 2 : Typische Schweißparatmeter für GMAW aus X 80 sections were lowered onto the prepared trench bottom. The results of the tests performed by Europipe on production pipe in km of pipe have been ordered recently. Field welding of grade X 80 pipe Pipeline construction needs welding operations by the thicknesses of 14.3 mm and 15.1 mm. Another 52 km are ordered for 2004. Figure 2 shows a view 484 3R international (42) Heft 7/2003 FACHBERICHTE The measured tensile strength and impact energy values conformed fully to the specification required for the production of grade X 100 plate. As a result, the production window became narrower. Heat treatment of 6]. Besides manual SMAW, automatic GMAW became increasingly important as an economic process because of a reduced welding time required and the toughness of the girth welds, which conform to typical specification requirements comfortably. Develoment of Grade X 100/X 120 of gas pipeline networks of about 158 km length in total was produced. Europipe supplied pipe of 48” diameter with beim CRCProzess Pass Consumab les Curren t [A ] Vo l tage [V ] We ld ing speed [cm/m in processes used is the CRC process that was also partly used for the construction of the Werne–to–Schlüchtern pipeline and the 100. No technological breakthroughs in TM rolling and accelerated cooling had been necessary. Only optimisation of the existing technology was |
| |
|
« Zurück zu Artikelübesicht
| Ausschnitt aus der Seite 51 |
komplette Inhalt der Seite 51 » |
| Bitte beachten Sie, daß der Inhalt dieser Seite kostenpflichtig ist. Der Text auf dieser Seite ist nach dem Zufallsprinzip strukturiert. Um den tatsächlichen Wortlaut zu erhalten, folgen Sie bitte diesem Link oder wiederholen Sie hier Ihre Suchanfrage gezielt in unserem Archiv. |
|
| 0.018 0.005 0.46 0.20 IV 36 x 16.0 mm 0.06 1.90 0.35 0.28 0.25 – 0.05 0.018 0.004 0.46 0.19 den Härtegrad der X100Güte zu erzielen, in dem die chemische Zusammensetzung des Stahls als auch die Kühlungsparameter während der Blechfertigung used in combination with fast cooling rates in the plate mill down to a very low coolingstop temperature, results in weld Fig . 5 : Test results on X 80 girth welds (CRC process) B i ld 5 : Testergebnisse % 200 270 J ~ –60 –10 °C2) 2)–60 °C for WT 12.7 mm, –10 °C for WT 25 mm (20 °C) DWTTtransition temparature I 737 MPa 800 MPa 0.92 18 % 200 J –20 °C IV 752 MPa 816 enables the desired property profile to be achieved through an optimised twostage rolling process in conjunction with a medium carbon at –20 °C are shown for the different wall thicknesses. Typically, the shear area values are higher for thinwall X Rt0.51) 1)Transverse tensile tests by roundbar specimens tensile strength Rm1) yield to tensile ratio Rt0.5 / Rm1) Elongation A51) CVN V 36 x 12.7 25 mm 0.06 1.93 0.32 0.30 0.24 – 0.05 0.018 0.005 0.46 0.19 Heat yield strength energy (CVN) measured was in excess of 200 J in all cases. It seems to be impossible to guarantee values 3 : Ansatz C für die Blechproduktion mit API X 100 Heat pipe size OD x WT C Mn Si the formation of large fractions of martensite in the microstructure, which has a detrimental effect on the toughness properties of variiert werden [7] Tabe 3 : Approach C for the production of plate in API grade X 100 Tab . an X80Umfangsschweißnähten (CRCProzess) Fig . 6 : Different approaches to reach the strength level of grade X 100 by varying production pipes show uniform strength properties for all the wall thicknesses tested. Tensile tests were performed using round bar specimens. Yieldtotensile ratios were still relatively high. The elongation values are lower than those known for grade X 70. The impact MPa 0.92 18 % 270 J ~ –50 °C V 767 799 MPa 796 836 MPa ~ 0.94 15 18 heat affected zone was observed. Experience gained meanwhile indicates that Approach C (Tabe 3) is the best choice. This approach 7 : Der Einfluss von Wanddicke auf DWTTestergebnisse bei –20 °C (X100Rohre) same steel composition could be used and only slight changes in the rolling conditions would be necessary. The results on contributes significantly to the success of this approach. The medium carbon content employed in Approach C ensures excellent toughness as Fig . 7 : Influence of wall thickness on DWT test results at –20°C (X 100 pipes) B i ld base metal. This effect cannot be adequately compensated for by using extremely low carbon contents. In addition, softening of the 100 material. Because of the relatively high carbon equivalent and the high strength level, the toughness of the longitudinal seam in excess of 300 J at low temperatures on a production basis. In Figure 7 , the DWT test results the steel chemistry as well as the cooling parameters during plate manufacture [7] B i ld 6 : Verschiedene Versuche acceptable for the purpose of current standardisation. Europipe has already produced hundreds of tonnes of grade X 100 pipe adopting content, a medium carbon equivalent and an optimised cooling process. The special potential of the existing rolling and cooling facilities well as fully satisfactory field weldability, despite the carbon equivalent, at about 0.46. The chemical composition should therefore be considered 485 3R international (42) Heft 7/2003 FACHBERICHTE Approach B, which adopts a carbon equivalent of only 0.43 and which is Approach C. Recent trials have covered the wall thickness range between 12.7 and 25.4 mm. It was demonstrated that the Mo Ni Cu Nb Ti N CEIIW PCM I 56 x 19.1 mm 0.07 1.90 0.30 0.17 0.33 0.20 0.05 |
| |
|
« Zurück zu Artikelübesicht
| Ausschnitt aus der Seite 52 |
komplette Inhalt der Seite 52 » |
| Bitte beachten Sie, daß der Inhalt dieser Seite kostenpflichtig ist. Der Text auf dieser Seite ist nach dem Zufallsprinzip strukturiert. Um den tatsächlichen Wortlaut zu erhalten, folgen Sie bitte diesem Link oder wiederholen Sie hier Ihre Suchanfrage gezielt in unserem Archiv. |
|
| different tests to evaluate the service behaviour. Figure 8 shows the influence of an ageing treatment on the Charpy transition OD x 16 mm WT grade X 100 pipe in the as delivered and aged conditions B i ld 8 a CEIIW of about 0.41 %, which is very low. The increase in the yield strength achieved by adding boron is impossible to install a grade X 100 pipeline in arctic regions without the use of crack arrestors. Europipe offers : View of full scale burst tests carried out on 56” x 19.1 mm and 36” x 16.0 mm grade also characterised by a reduced carbon content. It contains besides Cu, Ni, Cr, Nb and Ti, additions of V and Besides niobium, titanium and vanadium, the microalloying element boron was thought to be effective. Therefore, a series of laboratory plate the required properties are attained with a minimum of alloying additions, in order to control pipe production costs and to to X 120 It is of paramount importance to the pipe producer, and eventually to the customer, to ensure that reasons of technical feasibility and costeffective production, it is necessary in the context of grade X 100 to reassess and kept constant. Figure 10 illustrates the influence of boron on the yield strength of plate in comparison with boronfree heats. to manual and mechanised field welding, a finding which can be attributed to its reduced carbon content [8, 9]. For enabled grade X 120 material to be produced. The alloy design that enables this ultrahighstrength material to be produced is As can be seen from the figure, grade X 100 plate properties for 20 mm wall thickness were achieved with different types of crack arrestors to the industry. Effect of boron on highstrength line pipe steels in grades X 80 predominately bainitic microstructure. The Charpy Vnotch energy measured at –40 °C was in excess of 200 J. Only boronmicroalloyed heats x 16,0 mm Röhren aus X 100 Fig . 10 : Influence of boron on the yield strength of high strength linepipe material (15 18 mm wall thickness) B i ld 10 : Einfluss von Bor auf die erzielte Härte curve. There was only a slight decrease in toughness properties after a thermal treatment for 30 min at 250 °C. conducted by CSM as part of an ECSC funded research project [10]. So far, our experience has shown that it : CharpyTestergebnisse bei 36 AD x 16 mm WD Röhrenstahl X 100 in Lieferund in ausgelagertem Zustand Fig . 9 B. The carbon equivalent CEIIW of the chemical composition used in initial investigations was 0.55 %. By using narrow temperature Field coldbending trials were also completed with satisfactory results. Figure 9 shows photographs of full scale burst tests, which were combination of pipe chemical composition and thermomechanical treatment parameters ensuring a correct balance between strength, toughness and weldability was necessary. X 100 pipes B i ld 9 : Ansicht von umfassenden Bruchtests, durchgeführt bei 56 x 19,1 mm und 36 von hochfestem Rohrleitungsmaterial (15 18 mm Wanddicke) containing 0.06 % C exhibited lower Charpy values, between 100 and 170 J at –40 °C. Microalloying with boron also rolling trials were performed with the wellknown chemical composition for grade X 80 material starting from an extremely low CEIIW, redefine some of the requirements for mechanical properties, giving consideration to anticipated service conditions. The pipes produced were subjected to ranges for the individual rolling stages, which were based on precise Fig . 8 : Charpy test results on 36” make the use of high strength steel pipelines for longdistance transportation of gas under high pressure more attractive. A suitable is about 70 to 100 MPa, compared with boronfree material. In all cases, the base material was characterised by a 486 3R international (42) Heft 7/2003 FACHBERICHTE metal and the HAZ is limited. The X 100 material produced responds favourably at only 0.38 %. Besides the cooling rate (ca. 15 and 25 °C/ s) all rolling and cooling conditions were |
| |
|
« Zurück zu Artikelübesicht
| Ausschnitt aus der Seite 53 |
komplette Inhalt der Seite 53 » |
| Bitte beachten Sie, daß der Inhalt dieser Seite kostenpflichtig ist. Der Text auf dieser Seite ist nach dem Zufallsprinzip strukturiert. Um den tatsächlichen Wortlaut zu erhalten, folgen Sie bitte diesem Link oder wiederholen Sie hier Ihre Suchanfrage gezielt in unserem Archiv. |
|
| is deposited, the HAZ of the root pass undergoes hardness reduction as a result of reheating (normalising and tempering effects) steel Cooling rate (t8/5) Exellent field weldability of all liepie steel grades due to low C contents (limited martensite hardness) adjacent to the weld. This depends also on the pipe wall thickness. Finally, such an approach is limited by the chemical composition of grade X 100 would be practically the same as that for heavierwall grade X 80 pipe (additionally 487 3R international (42) Heft 7/2003 FACHBERICHTE ly measured Ar3 temperatures, a very high strength level could be achieved. Furthermore, 120 Mechan ical propertt t ies Mean val ues transverse Labora tory M i l Yield strength (round bar) Rt0.5 is no difference in the base material’s cold cracking behaviour between grade X 100 and grade X 120. Tabe 4 of welding consumables) have been already well developed. Field girth welding of X 100/X 120 Manual SMA and mechanised GMA necessary decisions in this context are therefore fraught with uncertainties for the pipe manufacturer. Plate production and field welding (development the critical period between root pass welding and hot pass welding have also a significant effect. As the hot pass cracking susceptibility during pipeline construction (field welding) Tab . 5 : Größen, die die Anfälligkeit für Rissbildung im kalten Zustand to 1.5 kJ per centimetre of the weld and per millimetre of the pipe wa thickness). Production experience available today of the base material adjacent to the longitudinal seam weld. This problem is existent to some extent also in the be underestimated in the case of grades X 100 and X 120 aimed at. The first problem is the softening steels under discussion. The same is true of grade X 120, representing the highest strength level aimed at. Therefore, there using soft cellulosic electrodes to deposit the root pass. This aspect and the increased HAZ hardness will not however have (MPa) 843 899 Yield strength (round bar) Rp2.0 (MPa) 1087 Tensile strength (round bar) Rm (MPa) 1128 1112 Yieldtotensile ratio Welding consumables Humidity at pipe ends Strength of steel and root pass weld metal Laying conditions welding should be sought for. These methods, in turn, would invariably lead to high cost of investment in the pipe während des Rohrleitungsbaues beeinflussen (Baustellenschweißen) Fac tors Microstructure of heat affected zone (HAZ) Hardness Hydrogen Stresses Chemical composition of the alloyed with molybdenum). With grade X 120, the same low C content can be used but at a marginally higher significantly reduced. Theoretically speaking, the residual stresses increase as the materials strength increases. This problem can be coped with by any significance, provided that the weld is maintained at a temperature ³ 50 °C during the critical initial stage and A5 (%) 14.3 12.6 Charpy toughness at – 40°C CVN (J) 227 196 Tabe 5 : Factors affecting the cold impact energy values ³ 215 J were measured at –30 °C. The mechanical properties are listed in Tabe 4. Aspects C equivalent (0.50 to 0.55 % according to IIW). The peak hardness in the HAZ of the girth welds plays so that the risk of cold cracking, which preferably may initiate at the toe notches of the root pass, is (round bar) Rt0.5 / Rm (%) 75 81 Yieldtotensile ratio (round bar) Rp2.0 / Rm (%) 96 Elongation (round bar) field welding of high strength linepipe in grades X 100 and X 120 do not pose any severe problems. The it can be easily managed. The second problem is associated with continuing the use of the proven submergedarc welding and X 120. This problem cannot be resolved by selecting a matching chemical composition for the weld metal alone. It would mills. Also, a quick changeover from the current welding methods to the required new methods would not be easy. The to be solved with respect to welding of the longitudinal seam The multiwire submergedarc welding process used universally to deposit need for a sufficiently overlapped welding and therefore adequate production safety. If it is not possible to reduce the heat any unscheduled interruptions during subsequent welding. It is well established that cold cracking in girth welds can occur only when case of materials in grades X 80 and X 100. But, the extent of the problem here is such that the twopass longitudinal seam weld in pipe is associated with a high heat input and leads to aspects that cannot of the root pass HAZ is initially governed by a 100 % martensitic structure and therefore dependent only on the in this connection is not sufficient enough to permit an assessment of the softening that occurs in the base material : Mechanical properties of plate material in grade X 120 Tab . 4 : Mechanische Eigenschaften von Blechmaterial aus X kJ per centimetre of the weld and per millimetre of the pipe wall thickness, needs to be reduced considerably (e.g. be rather necessary to reduce the heat input per pass. The average heat input per pass, which is at 2 an important role in the susceptibility to cold cracking (Tabe 5). High residual stresses developed in the weld area during carbon content. This aspect should be taken into account when stipulating restricted carbon equivalents in standards and specifications for highstrength achieving adequate strength and toughness for the weld metal of the twopass longitudinal seam weld in the highest strength material In girth welds, which are always characterised by cooling times of t8/5 = 2 to 6 s, the peak hardness the interpass temperature falls significantly below 50 °C. The carbon equivalent of highstrength line pipe steel grades on itself has input with the twopass submergedarc welding to the extent necessary without compromising on production safety, alternative welding methods involving multilayer no significant effect on the peak hardness under typical field welding conditions any more (short t8/5 cooling times, Figures 11). |
| |
|
« Zurück zu Artikelübesicht
| Ausschnitt aus der Seite 54 |
komplette Inhalt der Seite 54 » |
| Bitte beachten Sie, daß der Inhalt dieser Seite kostenpflichtig ist. Der Text auf dieser Seite ist nach dem Zufallsprinzip strukturiert. Um den tatsächlichen Wortlaut zu erhalten, folgen Sie bitte diesem Link oder wiederholen Sie hier Ihre Suchanfrage gezielt in unserem Archiv. |
|
| considerations for welding X 80 linepipe established; Oil & Gas Journal, Sept 15, 1997 [7] Schwinn, V.; Fluess, P.; Bauer, increasing steadily. From the manufacturers’ point of view, certain points must be observed when using higherstrength material grades. The minimum X 120, should be possible in principle for both SMAW and GMAW. Conclusions The predicted growth in energy consumption in burst tests. The initial results of the work directed to developing grade X 120 are encouraging with respect to the are currently being extensively studied. The knowledge gained from these studies can be made available to assist the pipeline operators art report from the manufacturer’s point of view, International pipeline technology conference, Brugge, Belgium, May 2000 [10] Demofonti, G.; Mannucci, commonplace today and do not imply very high additional costs. The manufacture of welding consumables matching grades X 100 and the wall thickness. In any case, the thicknesstodiameter ratio of high strength largediameter pipe should be in excess of 1 Liessem, A.; Knauf, G.; Niederhoff, K. A.; Bauer, J.: Development of largediameter pipe in grade X100 – State of the the coming decades necessitates severe efforts for transporting large amounts of natural gas to end users economically. Largediameter pipelines serve when planning a new pipeline project or when estimating the residual life of ageing pipelines. References [1] Gräf, M. K. realised. Several pipelines installed in Europe and North America in the past two decades show that the use of X H.G.: Production and Field Weldability Evaluation of X100 Linepipe, 13th Joint Meeting PRCIEPRG, New Orleans, USA 2001 [9] Hillenbrand, H.G.; but it is the filler weld metal deposited with ultrahighstrength basic vertical down electrodes that is more sensitive and therefore, First use of largediameter pipes of the steel GRS 550 TM (X80); 3R Internat. 25 (1986), No. 4, pp. 182 thickness should be 12 mm and for grade X 80 pipe and 16 mm for grade X 100 pipe. An basic weld metal in the filling and cap passes before the weld cools to room temperature. All these measures are pipeline”, 3 R internat. 41 (2002) No. 2 [4] Engelmann, H; Engel, A; Peters, P. A.; Düren, C.; Müsch, H.: materials. These properties have a significant bearing on the integrity of a pipeline and consequently the operating costs. These properties grade X 100 mechanical properties can be achieved. Crack arrest properties for certain pipe sizes were verified in full scale by supplying high quality pipe. The effect of pipe quality on the reduction of project costs will be more substantial the Application and Evaluation of highgrade linepipes in hostile Environments, Yokohama, Japan, November 2002 [8] Barsanti, L.; Pozzoli, G.; Hillenbrand, high pressure linepipe construction: An opening on X100 grade steel”, International Pipeline Conference, Calgary, Alberta, September 2002 [3] Bishop, M. J.: Production and progress work of plates for pipes with strength level of X 80 and above, International Conference on all possibilities to reduce the cost of pipeline projects in future. The pipe manufacturer can assist him in his endeavour D.; Reepmeyer, O.; Hillenbrand, H.G.; Schröder, J; Liessem, A.: Longitudinal welded X80 pipes for a high temperature, high pressure steam increase of the operating pressure combined with a smaller diameter and a constant wall thickness should be preferred to reducing linepipe; Oil & Gas Journal, January 1995 [6] Hillenbrand, H.G.; Niederhoff, K. A.; Hauck, G.; Perteneder, E.; Wellnitz, G.: Procedure, as the best and the safest means of transport. This paper presents an overview of the current requirements for high welding. This implies that the preheating temperature has to be such that hydrogen can adequately effuse from the ultrahigh strength plays the major role in respect of avoiding cold cracking when welding grade X 100 and particularly grade X 120 X100und X120Rohleitungsstählen (Berechnung nach Mannesmann Formeln) and Hillenbrand, H.G.: High Quality Pipe – a Prerequisite for Project Cost Reduction, 11th PRCIEPRG Joint Technical Meeting, Arlington, Virginia, G.; Harris, D.; Hillenbrand, H.G.; Barsanti, L.: Fracture behaviour of X100 gas pipeline by full scale tests, International Conference on the Application and Evaluation of highgrade linepipe in hostile Environments, Yokohama, Japan, November 2002 Fig . 11 : Hardenability of of a pipeline over its life by determining through investigations the fatigue, corrosion and ageing behaviour of pipe and pipe when the pipeline is constructed to the limit state design. Finally, the pipe manufacturers make contributions to reducing operational costs 488 3R international (42) Heft 7/2003 FACHBERICHTE Therefore, it has to be emphasised that it is not the base material, material. The preheating temperature to be selected must be appropriate to the weld metal’s chemistry and the hydrogen input during properties of the base material. Not only the steel grade, but also the usage factor and the operating pressure are strength steels and the associated developments. The technical possibilities are described. Also in the future, additional substantial improvements can be 80 linepipe causes no problems with respect to mechanical properties and welding. The development work led to the conclusion that % or better 1.5 %. The enormous pressure on the price of natural gas forces the pipeline operators to explore 193 [5] Chaudhari, V; Ritzmann, H. P.;Wellnitz, G.; Hillenbrand, H.G.; Willings, V.: German gas pipeline first to use new generation April 1997 [2] Barsanti, L; Hillenbrand, H.G. ; Mannucci, G.; Demofonti, D; Harris, D: Possible use of new materials for linepipe steel grades X 100 and X 120 (calculation acc. to Mannesmann formulas) B i ld 11 : Härtbarkeit von |
| |
|
|
| |
|
|
|
