scholarly journals Latest developments in mechanical properties and metallurgical features of high strength line pipe steels

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Diego Belato Rosado ◽  
Wim De Waele ◽  
Dirk Vanderschueren ◽  
Stijn Hertelé
Keyword(s):  
Pipe Steel ◽  
High Strength ◽  
Target Strength ◽  
Accelerated Cooling ◽  
Line Pipe ◽  
Recent Developments ◽  
Steel Grades ◽  
Increasing Demand ◽  
And Performance ◽  
Hostile Environments

In response to the increasing demand to improve both transportation efficiency and performance, the steel pipe industry has conducted extensive efforts to develop line pipe steel grades with superior metallurgical and mechanical (strength, toughness and ductility) properties in order to allow exploitation in hostile environments. This paper aims to give an overview of recent developments of high strength pipe steel grades as API 5L X70 and beyond, providing a detailed understanding of the continuous improvements with respect to a strain-based design context. Information regarding the metallurgy and processing, such as chemical composition, microstructural design, thermo-mechanical controlled process (TMCP) and accelerated cooling process (AcC), to achieve the target strength, ductility and toughness properties are discussed.

Niobium Microalloyed Line Pipe Steels: Technological Overview

2013 ◽  
Author(s):  
J. M. Gray ◽  
S. V. Subramanian
Keyword(s):  
Process Integration ◽  
Target Strength ◽  
Accelerated Cooling ◽  
Pipe Steels ◽  
Line Pipe ◽  
Steel Technology ◽  
Quantitative Understanding ◽  
Line Pipe Steel ◽  
Low Levels ◽  
Evolution Of Microstructure

A quantitative understanding of hierarchical evolution of microstructure is essential in order to design the base chemistry and optimize rolling schedules to obtain the morphological microstructure coupled with high density and dispersion of crystallographic high angle boundaries to achieve the target strength and fracture properties in higher grade line pipe steels, microalloyed with niobium. Product-process integration has been the key concept underlying the development of niobium microalloyed line pipe steel technology over the years. The development of HTP technology based on 0.1 wt % Nb and low interstitial was predicated by advances in process metallurgy to control interstitial elements to low levels (C <0.03wt% and N< 0.003wt%), sulfur to ultra-low levels (S<20ppm), as well as in product metallurgy based on advances in basic science aspects of thermo-mechanical rolling and phase transformation of pancaked austenite under accelerated cooling conditions, and toughness properties of heat affected zones in welding of niobium microalloyed line pipes. A historical perspective/technological overview of evolution of HTP for line pipe applications is the focus of this paper in order to highlight the key metallurgical concepts underlying Nb microalloying technology which have paved the way for successful development of higher grade line pipe steels over the years.

Development of X90 and X100 Steel Grades for Seamless Linepipe Products

2014 ◽  
Author(s):  
Diana Toma ◽  
Silke Harksen ◽  
Dorothee Niklasch ◽  
Denise Mahn ◽  
Ashraf Koka
Keyword(s):  
Wall Thickness ◽  
Deep Water ◽  
High Strength ◽  
Oil And Gas Industry ◽  
Pipe Material ◽  
Line Pipe ◽  
Materials Development ◽  
Additional Tool ◽  
Technical Requirements ◽  
Steel Grades

The general trend in oil and gas industry gives a clear direction towards the need for high strength grades up to X100. The exploration in extreme regions and under severe conditions, e.g. in ultra deep water regions also considering High Temperature/High Pressure Fields or arctic areas, becomes more and more important with respect to the still growing demand of the world for natural resources. Further, the application of high strength materials enables the possibility of structure weight reduction which benefits to materials and cost reduction and increase of efficiency in the pipe line installation process. To address these topics, the development of such high strength steel grades with optimum combination of high tensile properties, excellent toughness properties and sour service resistivity for seamless quenched and tempered pipes are in the focus of the materials development and improvement of Vallourec. This paper will present the efforts put into the materials development for line pipe applications up to grade X100 for seamless pipes manufactured by Pilger Mill. The steel concept developed by Vallourec over the last years [1,2] was modified and adapted according to the technical requirements of the Pilger rolling process. Pipes with OD≥20″ and wall thickness up to 30 mm were rolled and subsequent quenched and tempered. The supportive application of thermodynamic and kinetic simulation techniques as additional tool for the material development was used. Results of mechanical characterization by tensile and toughness testing, as well as microstructure examination by light-optical microscopy will be shown. Advanced investigation techniques as scanning electron microcopy and electron backscatter diffraction are applied to characterize the pipe material up to the crystallographic level. The presented results will demonstrate not only the effect of a well-balanced alloying concept appointing micro-alloying, but also the high sophisticated and precise thermal treatment of these pipe products. The presented alloying concept enables the production grade X90 to X100 with wall thickness up to 30 mm and is further extending the product portfolio of Vallourec for riser systems for deepwater and ultra-deep water application [1, 3, 4].

Development of High Strength Material and Pipe Production Technology for Grade X120 Line Pipe

2004 ◽  
Author(s):  
Hans-Georg Hillenbrand ◽  
Andreas Liessem ◽  
Karin Biermann ◽  
Carl Justus Heckmann ◽  
Volker Schwinn
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Point Of View ◽  
Accelerated Cooling ◽  
Pipe Production ◽  
Production Test ◽  
Low Carbon ◽  
Long Distance ◽  
Line Pipe ◽  
Economic Point

The increasing demand for natural gas will further influence the type of its transportation in the future, both from the strategic and economic point of view. Long-distance pipelines are a safe and economic means to transport the gas from production sites to end users. High-strength steels in grade X80 are nowadays state of the art. Grade X100 was recently developed but not yet utilised. The present-day technical limitations on the production of X120 line pipe namely the steel composition, the pipe forming and the welding are addressed in this paper. Production test results on X120 pipes are presented to describe the materials properties. A low carbon and low PCM steel with VNbTiB microalloying concept is used. In the plate rolling the main attention is turned to the heavy accelerated cooling. The large spring back that occurs during the U-forming step of the UOE process is one of the most complex aspects in forming X120. To handle this aspect FEM calculations were used to modify the forming parameters and to optimise the shape of the U-press tool. For optimising the existing welding procedure with respect to an avoidance of HAZ softening, a low heat input welding technology and new welding consumables were developed.

High strength line pipe steel plates based on TM-processing

1995 ◽  
Vol 92 (1) ◽  
pp. 109-119
Author(s):  
A. Streisselberger ◽  
J. Bauer ◽  
W. Schütz ◽  
V. Schwinn
Keyword(s):  
Pipe Steel ◽  
High Strength ◽  
Steel Plates ◽  
Line Pipe ◽  
Line Pipe Steel

Development of API 5L X70 Grade Steel Through Thin Slab Casting and Rolling Process

2019 ◽  
Author(s):  
Srimanta Sam ◽  
Neel Kant ◽  
Sujoy S. Hazra
Keyword(s):  
Sheet Thickness ◽  
High Strength ◽  
Production Costs ◽  
Target Strength ◽  
Accelerated Cooling ◽  
Slab Thickness ◽  
Thin Slab ◽  
Homogeneous Microstructure ◽  
Reheating Process ◽  
Grade Steel

API 5L grade steel is mainly used for oil and gas transportation. The economy of gas transportation via pipeline demands for high operating pressures and large pipe diameters in order to improve transportation capacity which requires heavy thickness and/or high grade of the steel. This pushed the steelmakers to develop high strength steels (HSS) with superior metallurgical and mechanical (strength, toughness and ductility) properties in order to allow exploitation in hostile environments. The technology of production of API 5L grade through conventional thick slab process is matured enough as it gives flexibility of using higher %C, lower casting speed, high slab thickness (200–250 mm), higher reheating temperature and time, high reduction etc. However due to slower cooling rate during liquid to γ transformation, possibilities of centerline segregation defect increases. Thin slab technology (TSCR), on the other side allows a reduction in energy consumption (because of lower slab thickness and elimination of reheating process), with consequent benefits in terms of production costs and pollution reductions. But producing API X65 and above though TSCR route with subzero impact and DWTT is a challenge because of the difficulties in achieving a refined and homogeneous microstructure due to lower reduction ratio from slab to finish sheet thickness. This paper aims to give an overview of recent developments of high strength pipe steel grades as API 5L X70 through TSCR route. Information regarding the metallurgy and processing, such as chemical composition, microstructural design, thermo-mechanical controlled process (TMCP) and accelerated cooling process (AcC), to achieve the target strength, ductility and toughness properties are discussed. Mechanical properties are well above the requirement of X70 at HR stage as well as after pipe formation. Excellent Impact and DWTT is achieved up to −40° C.

scholarly journals Microstructural Evolution and Carbon Partitioning in Interstitial Free Weld Simulated API 5L X60 Steel

2019 ◽  
Vol 58 (1) ◽  
pp. 206-217
Author(s):  
Hamid Reza Karimi Zarchi ◽  
Ali Khajesarvi ◽  
Seyed Sadegh Ghasemi Banadkouki ◽  
Mahesh C. Somani
Keyword(s):  
High Speed ◽  
Pipe Steel ◽  
Research Work ◽  
High Strength ◽  
Carbon Partitioning ◽  
Interstitial Free ◽  
Low Alloy Steel ◽  
Line Pipe ◽  
Heating And Cooling ◽  
Line Pipe Steel

AbstractThe microstructural characterizations and partitioning of carbon element in the weld heat affected zones of a commercial API 5L X60 line pipe steel were studied by applying a high speed heating and cooling dilatometry technique in the present research work. The hollow cylindrical specimens were quickly heated to 1000°C, soaked for only 5 s followed by continuous cooling to ambient temperature. Besides the construction of CCT diagram of this high strength low alloy steel using the dilatation data, the hardening response, microstructural features and carbon partitioning of weld simulated specimens were investigated. The obtained results showed that the hardening response of samples increased from 142 to 261HV10kg with increasing cooling rates. These hardening variations were attributed to the changes in microstructural features and carbon partitioning that occurred between the microconstituents present in the microstructures of weld simulated samples.

scholarly journals Mechanical Strength of Thermoplastic Polyamide Welded by Nd:YAG Laser

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1381 ◽  
Author(s):  
Pereira ◽  
Fernandes ◽  
Morais ◽  
Quintão
Keyword(s):  
Nd:Yag Laser ◽  
High Strength ◽  
Tensile Tests ◽  
Polyamide 6 ◽  
Robotic Welding ◽  
Lightweight Structures ◽  
Significant Interest ◽  
Fundamental Process ◽  
Recent Developments ◽  
Increasing Demand

Welding is a fundamental process in many industries. It is a fast-changing technology, continuously evolving, with recent developments in laser and robotic welding, virtual reality and machine learning. Focusing on laser welding, there is a significant interest in this technology, as well as an increasing demand for high-strength lightweight structures, replacing metals in some applications. This work presents an experimental study of the mechanical properties of three types of polyamide 6 joints welded by Nd:YAG laser. After welding, tensile tests were carried out in order to evaluate the influence of the joint type and weld passes on joint strength and weld stresses. The results showed that fairly high weld stresses could be achieved, indicating that good-quality welds were achieved.

scholarly journals Power Cooling

2016 ◽  
Vol 854 ◽  
pp. 225-230
Author(s):  
Erich Opitz ◽  
Alois Seilinger ◽  
Lukas Pichler ◽  
Olaf Silbermann ◽  
Axel Rimnac
Keyword(s):  
Cooling System ◽  
Hsla Steel ◽  
High Strength ◽  
Pipe Material ◽  
Line Pipe ◽  
Iron And Steel ◽  
Hot Strip ◽  
Finishing Mill ◽  
Steel Grades ◽  
Hot Strip Mills

During the last years international steel producers have been following a market trend to develop and produce new steel grades with higher strength and larger thickness. When attempting to improve the metallurgical properties in the cooling section, the existing cooling equipment in hot strip mills often reaches its limit. Primetals Technologies offers its Power Cooling solution to upgrade existing cooling lines as well as for new hot strip mills. With this type of equipment highest cooling rates can be achieved and therefore steel producers are capable of producing new steel grades with higher strength at lower costs. A new power cooling system was installed immediately behind the finishing mill gauge house at Wuhan Iron and Steel Company’s (WISCO) HSM No. 2 in Wuhan, China. The Power Cooling system widens the product range and gives WISCO the capability to produce high-strength steel grades (AHSS) with strength levels of more than 1,000 MPa, e.g. HSLA steel or as-hot-rolled multi-phase steel. Due to the extremely wide control range of the flow rate, the installation allows for maximum metallurgical flexibility. On the other hand, the new equipment allows for the most economic production of line-pipe material like API X80 in a thickness range up to 25.4 mm (1 inch).

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