scholarly journals Experimental Research on Fatigue Properties of X80 Pipeline Steel for Synthetic Natural Gas Transmission

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Li Yan–hua ◽  
Feng Hui ◽  
Chi Qiang ◽  
Fei Fan ◽  
Gao Xiong-xiong ◽  
...  
Keyword(s):  
Natural Gas ◽  
Base Metal ◽  
Hydrogen Content ◽  
Volume Fraction ◽  
Pipeline Steel ◽  
Fatigue Properties ◽  
High Grade ◽  
Long Distance ◽  
X80 Pipeline Steel ◽  
Synthetic Natural Gas

In recent years, many synthetic natural gas demonstration projects have been put into operation all over the world, and hydrogen is usually contained in synthetic natural gas. X80 is the most commonly used high-grade pipeline steel in the construction of natural gas pipelines. The compatibility between high-grade pipeline steel and hydrogen directly affects safety and reliability of long-distance pipelines. Therefore, in order to study the effect of hydrogen content on fatigue properties of high-grade pipeline steel, fatigue specimens were taken from base metal, spiral welds, and girth weld of submerged arc spiral welded pipes, respectively. Specifically, the total pressure was 12 MPa and hydrogen content was from 0 to 5vol%. Experimental results indicate that the hydrogen significantly increases the fatigue crack growth rate for both base metal, spiral weld, and heat-affected zone of X80 pipeline steel for about ten times compared with reference environment nitrogen, hydrogen would greatly reduce the fatigue life of the X80 pipeline steel, and the fatigue lifetime would decrease with the increase in hydrogen volume fraction. In order to ensure the safe operation of SNG pipeline, the hydrogen content should be controlled as low as possible.

A Selective and Sensitive Method for the Determination of Molybdenum in High Grade Pipeline Steels

2011 ◽  
Vol 80-81 ◽  
pp. 86-90 ◽  
Author(s):  
Xiaodong Shao
Keyword(s):  
Pipeline Steel ◽  
Sodium Thiocyanate ◽  
Pipeline System ◽  
High Grade ◽  
Ligand Complex ◽  
Long Distance ◽  
X80 Pipeline Steel ◽  
Relative Standard ◽  
Optimum Reaction

Pipeline system is the main form of transportation for oil and natural gas. High grade pipeline steel can effectively improve the security of long-distance transportation and to reduce costs, will become the main steel for gas pipeline project. A highly selective and sensitive spectrophotometric method for the determination of molybdenum in high grade pipeline steel has been presented. This method was based on the chromogenic reaction between molybdenum(V) and sodium thiocyanate. Employing stannous chloride as a reductant, molybdenum(VI) was reduced to molybdenum(V) at the room temperature. The obtained molybdenum(V) formed an orange-red-colored (1:5) ligand complex with thiocyanate. The absorbance of the complex was measured at 470nm, and the molar extinction coefficient (e) is 1.75´104L·mol-1·cm-1. Under the optimum reaction conditions the absorption value was proportional to the concentration of molybdenum in the range of 0.11%~0.89% (mass fraction), and the relative standard deviation was less than 3.0%. The proposed method was free from the interference from a large number of analytical important elements and has been applied satisfactorily to the determination of molybdenum in X80 pipeline steel and X70 pipeline steel samples with the improved accuracy and precision.

Effect of Ferrite Volume Fraction on Mechanical Properties of X80 Pipeline Steel

2014 ◽  
Vol 989-994 ◽  
pp. 212-215
Author(s):  
J. Liu ◽  
G. Zhu ◽  
W. Mao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Work Hardening ◽  
Single Phase ◽  
Volume Fraction ◽  
Pipeline Steel ◽  
X80 Pipeline Steel ◽  
Hardening Behavior ◽  
Two Phases ◽  
Better Than

The effect of volume fraction of ferrite on the mechanical properties including strength, plasticity and wok hardening was systematically investigated in X80 pipeline steel in order to improve the plasticity. The microstructures with different volume fraction of ferrite and bainite were obtained by heat-treatment processing and the mechanical properties were tested. The work hardening behavior was analyzed by C-J method. The results show that the small amount of ferrite could effectively improve the plasticity. The work hardening ability and the ratio of yield/tensile strength with two phases of ferrite/bainite would be obviously better than that with single phase of bainite. The improvement of plasticity could be attributed to the ferrite in which more plastic deformation was afforded.

Development and Production of Heavy Gauge X80 and High Strength X90 Pipeline Steels Utilizing TMCP/Optimized Cooling Process

2014 ◽  
Author(s):  
Guodong Zhang ◽  
Xuejun Bai ◽  
Douglas Stalheim ◽  
Shaopo Li ◽  
Wenhua Ding
Keyword(s):  
Mechanical Properties ◽  
Natural Gas ◽  
Pipeline Steel ◽  
Steel Plates ◽  
Plate Mill ◽  
Cooling Process ◽  
X80 Pipeline Steel ◽  
Natural Gas Transmission ◽  
Transmission Pipeline ◽  
Pipeline Project

Along with the increasing demand of oil and natural gas by various world economies, the operating pressure of the pipeline is also increasing. Large diameter heavy wall X80 pipeline steel is widely used in the long distance high pressure oil and gas transportation in China today. In addition, development of X90/X100 has begun in earnest to support the growing energy needs of China. With the wide use of X80 steels, the production technology of this grade has become technically mature in the industry. Shougang Group Qinhuangdao Shouqin Metal Materials Co., Ltd. (SQS) since 2008 has been steadily developing heavier thicknesses and wider plate widths over the years. This development has resulted in stable mass production of X80 pipeline steel plate in heavy wall thicknesses for larger pipe OD applications. The technical specifications of X80 heavy wall thickness and X90/X100 14.8–19.6 mm wall thicknesses, large OD (48″) requiring wide steel plates for the 3rd West-to-East Natural Gas Transmission Pipeline Project and the third line of Kazakhstan-China Main Gas Pipeline (The Middle Asia C Line) and the demonstration X90/X100 line (part of the 3rd West-East Project) in China required changes to the SQS plate mill process design. Considering the technology capability of steelmaking and the plate mill in SQS, a TMCP+OCP (Optimized Cooling Process) was developed to achieve stable X80 and X90/X100 mechanical properties in the steel plates while reducing alloy content. This paper will describe the chemistry, rolling process, microstructure and mechanical properties of X80 pipeline steel plates produced by SQS for 52,000 mT of for the 3rd West-to-East Natural Gas Transmission Pipeline Project and 5,000 mT for the Middle Asia C Line Project along with 1000 tons of 16.3 mm X90/X100 for the 3rd West-East demonstration pipeline. The importance of the slab reheating process and rolling schedule will be discussed in the paper. In addition, the per pass reductions logic used during recrystallized rough rolling, and special emphasis on the reduction of the final roughing pass prior to the intermediate holding (transfer bar) resulting in a fine uniform prior austenite microstructure will be discussed. The optimized cooling (two phase cooling) application after finish rolling guarantees the steady control of the final bainitic microstructure with optimum MA phase for both grades. The plates produced by this process achieved good surface quality, had excellent flatness and mechanical properties. The pipes were produced via the JCOE pipe production process and had favorable forming properties and good weldability. Plate mechanical properties successfully transferred into the required final pipe mechanical properties. The paper will show that the TMCP+OCP produced X80 heavy wall and 16.3 mm X90 wide plates completely meet the technical requirements of the three pipeline projects.

Effects of M/A Islands Microstructure Characteristic on Mechanic Properties of High Grade Pipeline Steel

2010 ◽  
Author(s):  
Ke Tong ◽  
Xiaodong Shao ◽  
Lixia Zhu ◽  
Qiang Liu ◽  
Jinfeng Li
Keyword(s):  
Volume Fraction ◽  
Pipeline Steel ◽  
Yield Ratio ◽  
Material Strength ◽  
High Grade ◽  
Microstructure Characteristics ◽  
Average Dimension ◽  
Microstructure Characteristic

The microstructure characteristic of martensite/austenite (M/A) islands of X80-1#, X80-2#, X100-3#, X100-4# steel pipelines come from different manufacturer were investigated by OM and SEM contrastively, and the influence of M/A islands microstructure characteristics of pipelines were studied combining with tests of mechanic properties. The result shows that the effect of the M/A islands volume fraction, average dimension, form and distribution on the material strength, yield ratio and toughness were distinct. When the M/A islands distribute uniformly with small size and spherical or crossed strip form, under the certain volume fraction, the pipeline steel exhibits excellent strength-toughness matching.

Improvement in Ovality of Pipeline Steel X80 with Weld Power under Multi-Wire SAW Welding Process

2011 ◽  
Vol 239-242 ◽  
pp. 1823-1831 ◽  
Author(s):  
Yi Bo Li ◽  
Ming Hui Huang ◽  
Xin Jiang Lu
Keyword(s):  
Oil And Gas ◽  
Pipeline Steel ◽  
Welding Process ◽  
Element Model ◽  
Simulation Method ◽  
Source Model ◽  
Long Distance ◽  
X80 Pipeline Steel ◽  
Wire Saw ◽  
Welding Processes

Pipeline steel X80 is a kind of advanced high grade steel and commonly used in long-distance transportation of oil and gas. Ovality of the pipe plays key role in improving its crushing strength. In this paper, a simulation method is proposed to improve the performance of ovality of X80 Pipeline Steel. First, a 3D thermo-mechanical coupled finite element model of the multi-wire SAW welding processes is built using MSC.MARC, upon which parameters of double ellipsoid heat source model is determined. Then, the relationship between weld power and ovality is studied under difference process inputs and a satisfactory weld power is found to decrease the ovality of the pipeline steel. Finally, validation and prediction of deformation and ovality of the pipeline is carried out via plate welding experiments.

Synergistic action of hydrogen and stress concentration on the fatigue properties of X80 pipeline steel

2017 ◽  
Vol 700 ◽  
pp. 321-330 ◽  
Author(s):  
Teng An ◽  
Shuqi Zheng ◽  
Huangtao Peng ◽  
Xiangli Wen ◽  
Liqiang Chen ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Pipeline Steel ◽  
Synergistic Action ◽  
Fatigue Properties ◽  
X80 Pipeline Steel

Hydrogen effects on X80 pipeline steel in high-pressure natural gas/hydrogen mixtures

2017 ◽  
Vol 42 (11) ◽  
pp. 7404-7412 ◽  
Author(s):  
Bo Meng ◽  
Chaohua Gu ◽  
Lin Zhang ◽  
Chengshuang Zhou ◽  
Xiongying Li ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Pipeline Steel ◽  
X80 Pipeline Steel ◽  
Hydrogen Mixtures

Effect of Hydrogen Content in Natural Gas Blend on the Mechanical Properties of a L485-MB Low-Alloyed Steel

2020 ◽  
Author(s):  
Hamza Ez-Zaki ◽  
Frederic Christien ◽  
Cédric Bosch ◽  
Laurent Briottet ◽  
Maxime Bertin ◽  
...  
Keyword(s):  
Natural Gas ◽  
Partial Pressure ◽  
Hydrogen Content ◽  
Pipeline Steel ◽  
Pure Hydrogen ◽  
Testing Conditions ◽  
Partial Pressures ◽  
Cone Type ◽  
Type Fracture ◽  
Low Alloyed Steel

Abstract The purpose of the present work is to study the effect of the hydrogen content in a H2-NG (Natural Gas) blend on the mechanical behavior of a C-Mn low alloy steel L485-MB (NF EN ISO 3183) under monotonic loading. Different testing conditions were explored for the blend: 2% H2-NG, 25% H2-NG, 100% H2 and 100% NG at a total pressure of 8.5 MPa using two slow strain rates: 10−4 s−1 and 10−6 s−1. Tests in the blend were compared to those under pure hydrogen at the same partial pressures. Furthermore, two surface roughnesses have been explored, one corresponding to a mirror polish, the other as lathed. The embrittlement has been assessed by necking measurements and fracture analysis for the whole testing conditions. The results show a drop of ductility with the increase of partial pressure of hydrogen in NG. Besides, no significant effect of hydrogen were observed on flow stress. In addition, the L485-MB pipeline steel presents a shear type fracture mode in high partial pressure of hydrogen, whereas a cup and cone type fracture were observed in air, NG and low partial pressure of hydrogen in NG (0.2 MPa H2).

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