The Development of Large-Diameter HighStrength Line Pipe for Low-Temperature Service

1976 ◽  
Author(s):  
Maurice F. Baldy
Keyword(s):  
Low Temperature ◽  
Large Diameter ◽  
Line Pipe

Development of X80M Line Pipe Steel for Spiral Welded Pipes With Low Temperature Toughness and Excellent Weldability

2014 ◽  
Author(s):  
Nuria Sanchez ◽  
Özlem E. Güngör ◽  
Martin Liebeherr ◽  
Nenad Ilić
Keyword(s):  
Low Temperature ◽  
Life Cycle Cost ◽  
Volume Fraction ◽  
Large Diameter ◽  
Pipe Production ◽  
Strain Accumulation ◽  
Long Distance ◽  
Line Pipe ◽  
Low Temperature Toughness ◽  
Welded Pipe

The unique combination of high strength and low temperature toughness on heavy wall thickness coils allows higher operating pressures in large diameter spiral welded pipes and could represent a 10% reduction in life cycle cost on long distance gas pipe lines. One of the current processing routes for these high thickness grades is the thermo-mechanical controlled processing (TMCP) route, which critically depends on the austenite conditioning during hot forming at specific temperature in relation to the aimed metallurgical mechanisms (recrystallization, strain accumulation, phase transformation). Detailed mechanical and microstructural characterization on selected coils and pipes corresponding to the X80M grade in 24 mm thickness reveals that effective grain size and distribution together with the through thickness gradient are key parameters to control in order to ensure the adequate toughness of the material. Studies on the softening behavior revealed that the grain coarsening in the mid-thickness is related to a decrease of strain accumulation during hot rolling. It was also observed a toughness detrimental effect with the increment of the volume fraction of M/A (martensite/retained austenite) in the middle thickness of the coils, related to the cooling practice. Finally, submerged arc weldability for spiral welded pipe manufacturing was evaluated on coil skelp in 24 mm thickness. The investigations revealed the suitability of the material for spiral welded pipe production, preserving the tensile properties and maintaining acceptable toughness values in the heat-affected zone. The present study revealed that the adequate chemical alloying selection and processing control provide enhanced low temperature toughness on pipes with excellent weldability formed from hot rolled coils X80 grade in 24 mm thickness produced at ArcelorMittal Bremen.

Development of Heavy Gauge X70 Helical Line Pipe

2018 ◽  
Author(s):  
L. E. Collins ◽  
K. Dunnett ◽  
T. Hylton ◽  
A. Ray
Keyword(s):  
Low Temperature ◽  
Large Diameter ◽  
High Strength ◽  
Helical Line ◽  
Slab Thickness ◽  
Long Distance ◽  
Austenite Grain Size ◽  
Line Pipe ◽  
Nitrogen Levels ◽  
Low Temperature Toughness

A decade ago, the pipeline industry was actively exploring the use of high strength steels (X80 and greater) for long distance, large diameter pipelines operating at high pressures. However in recent years the industry has adopted a more conservative approach preferring to utilize well established X70 grade pipe in heavier wall thicknesses to accommodate the demand for increased operating pressures. In order to meet this demand, EVRAZ has undertaken a substantial upgrade of both its steelmaking and helical pipemaking facilities. The EVRAZ process is relatively unique employing electric arc furnace (EAF) steelmaking to melt scrap, coupled with Steckel mill rolling for the production of coil which is fed into helical DSAW pipe mills for the production of large diameter line pipe in lengths up to 80 feet. Prior to the upgrade production had been limited to a maximum finished wall thickness of ∼17 mm. The upgrades have included installation of vacuum de-gassing to reduce hydrogen and nitrogen levels, upgrading the caster to improve cast steel quality and allow production of thicker (250 mm) slabs, upgrades to the power trains on the mill stands to achieve greater rolling reductions, replacement of the laminar flow cooling system after rolling and installation of a downcoiler capable of coiling 25.4 mm X70 material. As well a new helical DSAW mill has been installed which is capable of producing large diameter pipe in thicknesses up to 25.4 mm. The installation of the equipment has provided both opportunities and challenges. Specific initiatives have sought to produce X70 line pipe in thicknesses up to 25.4 mm, improve low temperature toughness and expand the range of sour service grades available. This paper will focus on alloy design and rolling strategies to achieve high strength coupled with low temperature toughness. The role of improved centerline segregation control will be examined. The use of scrap as a feedstock to the EAF process results in relatively high nitrogen contents compared to blast furnace (BOF) operations. While nitrogen can be reduced to some extent by vacuum de-gassing, rolling practices must be designed to accommodate nitrogen levels of 60 ppm. Greater slab thickness allows greater total reduction, but heat removal considerations must be addressed in optimization of rolling schedules to achieve suitable microstructures to achieve both strength and toughness. This optimization requires definition of the reductions to be accomplished during roughing (recrystallization rolling to achieve a fine uniform austenite grain size) and finishing (pancaking to produce heavily deformed austenite) and specification of cooling rates and coiling temperatures subsequent to rolling to obtain suitable transformation microstructures. The successful process development will be discussed.

scholarly journals Experimental Study on Deformation Behavior and Compressive Strength of Concrete Cast in Steel Tube Arches under Low-Temperature Conditions

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Tuo Shi ◽  
Nianchun Deng ◽  
Xiao Guo ◽  
Wen Xu ◽  
Shi Wang
Keyword(s):  
Compressive Strength ◽  
Low Temperature ◽  
Performance Test ◽  
Large Diameter ◽  
Test Site ◽  
Steel Tube ◽  
Design Strength ◽  
Curing Conditions ◽  
Expansive Agent ◽  
Arch Bridges

Taking the construction of a concrete-filled steel tube (CFST) arch bridge (part of the Sichuan-Tibet Railway) in low temperatures as the test site, firstly the deformation performance test of concrete was carried out. Following this initial testing, measurement of compressive strength and shrinkage performance was conducted in large-diameter CFSTs under a variety of curing conditions. Experimental results showed that the expansion effect of Ca-Mg composite expansive agent in concrete was better than that of other expansive agents at any stage. Under low-temperature curing (0°C), the sampling strength of the large-diameter CFSTs reached 73.5% of the design strength at 28 d in the presence of a nonthermal curing system. The design strength itself was reached, when a curing system involving a thermal insulation film was applied, and use of this film also led to improvements in concrete shrinkage. The results suggested that a Ca-Mg composite expansive agent, combined with an insulation film curing system, should be the technique selected for concrete pumping construction of CFST arch bridges in Tibet.

The Use of Optimized ERW Technique to Improve Low Temperature Fracture Toughness of Welded Pipes

2020 ◽  
Author(s):  
Muhammad Rashid ◽  
Timothy Hylton ◽  
Neil Anderson ◽  
Laurie Collins ◽  
Leijun Li
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Low Temperature ◽  
Weld Seam ◽  
Peak Temperature ◽  
Line Pipe ◽  
Squeeze Pressure ◽  
Treatment Practices ◽  
Treatment Techniques ◽  
Research Activities

Abstract It is understood that the bondline microstructure of the line pipe ERW seam can be a zone of weakness in the pipe. To overcome this weakness, several research projects utilizing various line pipe steel grades and welding and heat treatment techniques have been conducted at EVRAZ NA. The overall goal of these efforts has been to understand the development of bondline microstructure during the ERW process and improve the weld seam fracture toughness for low temperature applications. These research activities included mill trials and Gleeble simulations. It was realized that a high toughness ERW weld seam is only possible through a tightly controlled combination of weld power, forging (squeeze) pressure, and welding speed. Research studies have indicated that the as-welded seam may not pass the standard ERW destructive tests if proper heat input and adequate squeeze pressure are not applied. Post weld heat treatment (normalizing) practice was also found to be a key element in the development of the appropriate bondline microstructure for higher toughness. Samples from pipes normalized using different heat treatment practices produced different bondline microstructures and hence different toughness properties. It was found through this study that a low (but still higher than the upper critical temperature Ac3) normalizing peak temperature and adequate soak time at the peak temperature result in improved Charpy toughness of ERW bondline microstructure.

Buckling Resistance of Large Diameter Spiral Welded Linepipe

2004 ◽  
Author(s):  
Tom Zimmerman ◽  
Chris Timms ◽  
Jueren Xie ◽  
James Asante
Keyword(s):  
Oil And Gas ◽  
Weld Seam ◽  
Large Diameter ◽  
Ground Movement ◽  
Finite Element Analyses ◽  
Line Pipe ◽  
Diameter Pipe ◽  
Buckling Resistance ◽  
Analytical Research ◽  
Full Scale Tests

This paper contains the results of an experimental and analytical research program to determine the compressive buckling resistance of large-diameter, spiral-welded linepipe. Buckling resistance is important for pipe intended for service in Arctic, oil and gas pipeline systems, where pipes may be subjected to high bending strains caused by various ground movement events. The experimental work consisted of four full-scale tests of 30-inch (762 mm) diameter pipe subjected to various combinations of internal pressure, axial force and bending. The pipe specimens were fabricated using two material grades (X70 and X80) and two D/t ratios (82 and 48). Finite element analyses of the four tests were conducted to develop a better understanding of specimen behavior. The results suggest that spiral welded linepipe is as good as longitudinally welded line pipe in terms of buckling capacity. The spiral weld seam was in no way detrimental to the pipe performance.

Large-Diameter Line Pipe Expanding Process

2012 ◽  
Vol 192 ◽  
pp. 180-184 ◽  
Author(s):  
Ai Xia He ◽  
Rong Chang Li
Keyword(s):  
Process Parameters ◽  
Large Diameter ◽  
Dimensional Accuracy ◽  
Optimization Method ◽  
Main Process ◽  
Shape Accuracy ◽  
Line Pipe ◽  
Factors Affecting ◽  
Array Optimization

Mechanical expanding process for large diameter line pipe, a detailed analysis of factors affecting the quality of the final products of the mechanical expansion and proposed optimization using orthogonal array optimization method, as an indicator of dimensional accuracy and shape accuracy of the products, combination of a variety of specifications of mechanical expanding products, the main process parameters to be optimized. Analysis and discussion of results, revealing the degree of influence of various factors on the quality of the final product, and gives the optimum combination of the results. Experiments show that the combination of optimized process parameters, and more help to improve the accuracy of the size and shape of products.

Numerical Simulation of UOE Pipe Process and its Effect on Pipe Mechanical Behavior in Deep-Water Applications

2015 ◽  
Author(s):  
Giannoula Chatzopoulou ◽  
Spyros A. Karamanos ◽  
George E. Varelis
Keyword(s):  
Deep Water ◽  
Manufacturing Process ◽  
Large Diameter ◽  
Structural Response ◽  
Structural Instability ◽  
External Pressure ◽  
Line Pipe ◽  
Simulation Tools ◽  
Large Diameter Pipes ◽  
Pipe Manufacturing

Large-diameter thick-walled steel pipes during their installation in deep-water are subjected to a combination of loading in terms of external pressure, bending and axial tension, which may trigger structural instability due to excessive pipe ovalization with catastrophic effects. In the present study, the UOE pipe manufacturing process, commonly adopted for producing large-diameter pipes of significant thickness, is considered. The study examines the effect of UOE line pipe manufacturing process on the structural response and resistance of offshore pipes during the installation process using nonlinear finite element simulation tools.

Standardization of Flattening Procedure of Transverse to Pipe Axis Strap Tensile Samples

2018 ◽  
Author(s):  
M. Rashid ◽  
S. Chen ◽  
L. E. Collins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Tensile Testing ◽  
Standard Procedure ◽  
Large Diameter ◽  
Spring Back ◽  
Pipe Axis ◽  
Element Analysis ◽  
Line Pipe ◽  
Experimental Approaches

Tensile testing on large diameter line pipe is generally done using strap samples obtained in the transverse to pipe axis (TPA) orientation of a pipe. The strap samples are then flattened and machined prior to testing. Although the standardized tensile testing is well documented, the variability in the reported TPA tensile properties of the same material tested within a lab or at different labs has always been an issue. Recent work conducted at EVRAZ NA research lab has identified flattening as the main source of the variability in reported yield strength (YS) values for line pipe. The lack of a standard procedure for flattening TPA strap samples is a major obstacle to obtaining consistent results. Therefore, the main objective of this current study was to establish a standardized flattening procedure for TPA strap samples. Both finite element analysis (FEA) and experimental approaches were adopted. Various flattening methods and fixtures were studied. Extensive flattening experiments were conducted on TPA samples from different line pipe products. Results showed that the spring back after flattening in a TPA sample is different for pipes with different gauge and grades. It was established that consistent flattening can be achieved using appropriate fixtures for differerent ranges of tubular products defined by grade, diameter and gauges. Evaluation of the flattening fixture designs and experimental results are discussed in this paper.

Automatic issuance of quality certificates for large-diameter gas and oil line pipe

Metallurgist ◽  
1984 ◽  
Vol 28 (9) ◽  
pp. 324-325
Author(s):  
Yu. A. Mednikov ◽  
V. P. Matveev ◽  
Yu. A. Gerasin
Keyword(s):  
Large Diameter ◽  
Line Pipe
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