Study of lath morphology bainite in high-strength pipe steel

2013 ◽  
Vol 55 (5-6) ◽  
pp. 287-293 ◽  
Author(s):  
N. G. Kolbasnikov ◽  
O. G. Zotov ◽  
A. I. Shamshurin ◽  
A. A. Luk’yanov
Keyword(s):  
Pipe Steel ◽  
High Strength ◽  
Lath Morphology

The Development and Experimental Study on High Strength and Toughness Drill Pipe Steel

2011 ◽  
Vol 287-290 ◽  
pp. 1024-1032
Author(s):  
Feng Hu ◽  
Li Hong Han ◽  
Hang Wang ◽  
Yao Rong Feng ◽  
He Lin Li
Keyword(s):  
Electron Microscopy ◽  
Yield Strength ◽  
Pipe Steel ◽  
Drill Pipe ◽  
Control Process ◽  
High Strength ◽  
Alloy Element ◽  
Deep Wells ◽  
Alloy Carbon ◽  
The Impact

With the development of oil industry, the high strength-toughness drill pipe suited to the task of sour environment and ultra deep wells would be considered more and more important. A new drill pipe steel, which was designed with the proper decrease of C content and increase of Cr, Ni, Mo, Nb and V alloy element, was developed and studied in this study. Large deformation hot rolling technology was used to obtain ultrafine grains microstructure. The results showed that the yield strength of this new drill pipe steel had reached 150ksi with the impact toughness more than 150J, which can perfectly meet the “leak-before-break” crack principle. The new low-alloy carbon steel drill pipe in the controlled yield strength grade 150ksi showing excellent sulfide stress cracking resistance and strength-toughness have been developed. Based on the observation of scanning electron microscopy and transmission electron microscopy, several kinds of carbide particles including (Nb, Mo, V)C with nanometer scale, were distributed in tempered sorbite matrix. The objective of this work was to study the relationship between carbide precipitation and strength-toughness by optimizing element design, thermo mechanical control process and heat treatment of drill pipe steel.

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

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.

scholarly journals Failure Analysis of Weld Metal Cracking in Weld Joint of API 5L X 75 Pipelines Steel

2018 ◽  
Vol 7 (4.7) ◽  
pp. 401
Author(s):  
Abbas Kamil ALrubaeiy ◽  
. . ◽  
. .
Keyword(s):  
Weld Metal ◽  
Failure Analysis ◽  
Weld Joint ◽  
Pipe Steel ◽  
High Strength ◽  
Cold Cracking ◽  
Steel Alloy ◽  
Preheat Temperature ◽  
Thin Walled

The development of steel alloy which result thin walled, high strength API 5L X75 grade, a restricting parameter controlling widespread use of X75 is the susceptibility to weld metal tracks. The excellent weld ability of this grade of the pipe steel has enhanced the potential for the use of high strength cellulose consumable like E6010 in root pass welding, but the risk of hydrogen assisted cold cracking (HACC) is also increased because of the high strength weld metal. This investigation outlines , the use of grade (E6010) of commercial cellulose consumable to assess conditions leading to hydrogen assisted cold cracking in the diluted weld metal. The research contained clarification of the link among microstructure; preheat temperature and hardness amounts for the weld consumable and its effect on cracking susceptibility. The cracking morphology studies indicated that there are many ways in which the crack can propagate in the weld metal and HAZ region. The mode of cracking observed was microvoide coalescence.    

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.

On Preparation of In Situ Composite Steel with Ultra-High Strength and its Thermal Stability

2010 ◽  
Vol 152-153 ◽  
pp. 436-440
Author(s):  
Jun Zhao ◽  
Han Zhang ◽  
Zhi Wang ◽  
Hong Yan Zhai ◽  
Quan Xing Wen ◽  
...  
Keyword(s):  
Cold Rolling ◽  
Crystal Size ◽  
Steel Plate ◽  
Lath Martensite ◽  
Rolling Direction ◽  
High Strength ◽  
Long Time ◽  
New Type ◽  
Lath Morphology

A new type of in-situ composite nano-multilayer plate with ultra-high strength (b 2112 MPa), Q235 steel plate with nano-layered structure of lath martensite produced by severe cold-rolling, was developed. After cold-rolling, subsequent annealing has great effect on the deformed lath morphology and grain refinement. Microstructure recrystallizing course have taken place after long time annealing at 350 °C. The recrystallization activation energy is 151 kJmol-1. Microstructure characteristics along rolling direction arrangement was decreased after annealing at 400 °C. In addition to the ultrafine ferrite grains, nano-carbides precipitated uniformly in the specimen annealed at 500 °C. Annealing at and above 600 °C resulted in coarse ferrite grains with spheroidized coarse carbides, causing grain growth. The average crystal size is about 4.7 m after annealing for 60 min at 600 °C.

Research on Tempering Process of LZ20Mn2 Seamless Pipe for Axle

2010 ◽  
Vol 97-101 ◽  
pp. 4491-4496
Author(s):  
Zhong Guo Huang ◽  
Hong Lei Dong ◽  
Qing Hua Yuan ◽  
Jian Song ◽  
Jia Fan
Keyword(s):  
Pipe Steel ◽  
High Strength ◽  
Seamless Pipe ◽  
Tempering Temperature ◽  
High Toughness ◽  
Fine Grain ◽  
Change Trend ◽  
The One ◽  
Holding Temperature ◽  
Tempering Process

In order to find out the effects of tempering process on properties of axle steel, the thesis analyzes the change trend of properties of LZ20Mn2 axle steel pipe with variation of tempering temperature. And SEM was used to observe and analyze the fracture. The results show that the strength and hardness of LZ20Mn2 axle steel drop gradually and its toughness and plasticity are increased when tempering temperature goes up. Change of material properties trends to slow down after tempering at 570 °C. From point view of toughness, the technology for the best quality LZ20Mn2 axle pipe steel is the one with quenching at 880 °C with temperature holding for 30min, and tempering at 530 °C with 90min holding temperature. After heat treatment, the microstructure is fine grain size tempered sorbite structure and has good plasticity and toughness, so it can meet the requirement of both high strength and high toughness for axle.

Evaluation of Anisotropic Pipe Steel Stress-Strain Relationships Influence on Strain Demand

2012 ◽  
Author(s):  
James D. Hart ◽  
Nasir Zulfiqar ◽  
Joe Zhou
Keyword(s):  
Strain Hardening ◽  
Pipe Steel ◽  
High Strain ◽  
Strain Curve ◽  
High Strength ◽  
Strain Response ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Hardening Modulus ◽  
Strain Relationship

Buried pipelines can be exposed to displacement-controlled environmental loadings (such as landslides, earthquake fault movements, etc.) which impose deformation demands on the pipeline. When analyzing pipelines for these load scenarios, the deformation demands are typically characterized based on the curvature and/or the longitudinal tension and compression strain response of the pipe. The term “strain demand” is used herein to characterize the calculated longitudinal strain response of a pipeline subject to environmentally-induced deformation demands. The shape of the pipe steel stress-strain relationship can have a significant effect on the pipe strain demands computed using pipeline deformation analyses for displacement-controlled loading conditions. In general, with sufficient levels of imposed deformation demand, a pipe steel stress-strain curve with a relatively abrupt or “sharp” elastic-to-plastic transition will tend to lead to larger strain demands than a stress-strain curve with a relatively rounded elastic-to-plastic transition. Similarly, a stress-strain curve with relatively low strain hardening modulus characteristics will tend to lead to larger strain demands than a stress-strain curve with relatively high strain hardening modulus characteristics. High strength UOE pipe can exhibit significant levels of anisotropy (i.e., the shapes of the stress-strain relationships in the longitudinal tension/compression and hoop tension/compression directions can be significantly different). To the extent that the stress-strain curves in the different directions can have unfavorable shape characteristics, it follows that anisotropy can also play an important role in pipeline strain demand evaluations. This paper summarizes a pipeline industry research project aimed at evaluation of the effects of anisotropy and the shape of pipe steel stress-strain relationships on pipeline strain demand for X80 and X100 UOE pipe. The research included: a review of pipeline industry literature on the subject matter; a discussion of pipe steel plasticity concepts for UOE pipe; characterization of the anisotropy and stress-strain curve shapes for both conventional and high strain pipe steels; development of representative analytical X80 and X100 stress-strain relationships; and evaluation of a large matrix of ground-movement induced pipeline deformation scenarios to evaluate key pipe stress-strain relationship shape and anisotropy parameters. The main conclusion from this work is that pipe steel specifications for high strength UOE pipe for strain-based design applications should be supplemented to consider shape-characterizing parameters such as the plastic complementary energy.

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