Effect of Tensile Property Distribution on Strain-Based Design Application of High Strength UOE Line Pipe

2006 ◽  
Author(s):  
Yasuhiro Shinohara ◽  
Eiji Tsuru ◽  
Takuya Hara ◽  
Hitoshi Asahi ◽  
Yoshio Terada ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Aging ◽  
High Strength ◽  
Strength Distribution ◽  
Circumferential Direction ◽  
Strain Variation ◽  
Line Pipe ◽  
Property Distribution ◽  
Coating Application ◽  
Thermal Coating

For line pipe to which a strain-based design is applied, control of mechanical properties such as yield to tensile strength (Y/T) ratio, yield strength (YS) and flow stress at a low strain is required. These mechanical properties generally change during thermal coating treatment. A high strength UOE line pipe that is less susceptible to strain aging has recently been developed. In UOE pipes, mechanical properties change along the circumferential direction. However, the strength distribution has received little attention. Furthermore, the extent to which the change in strength along the circumferential direction affects the strain limits in strain-based design application is unclear. In this paper, firstly, the pipe forming strain variation and mechanical properties distribution along the circumferential direction of the X80 UOE line pipe suitable to the application of strain-based design are presented. Secondly, change in the properties distribution after thermal coating application is examined. Finally, the effect of strength distribution on the strain limits in strain-based design is discussed.

Change of Mechanical Properties of High Strength Line Pipe by Thermal Coating Treatment

2005 ◽  
Author(s):  
Yasuhiro Shinohara ◽  
Takuya Hara ◽  
Eiji Tsuru ◽  
Hitoshi Asahi ◽  
Yoshio Terada ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Uniform Elongation ◽  
High Strength ◽  
Secondary Phase ◽  
Longitudinal Direction ◽  
Dual Phase ◽  
Line Pipe ◽  
Thermal Coating ◽  
Production Conditions

In strain-based design, the overmatch condition in the girth weld portion primarily must be maintained. The pipes may also be required to have a low yield to tensile (Y/T) ratio and a high uniform elongation (U.EL) in the longitudinal direction to achieve a high compressive buckling strain. However, change in the mechanical properties by heating during coating treatment has not been paid attention so much. Furthermore, how much the mechanical properties change is affected by production conditions is unclear. This study aims to clarify firstly the relation between the mechanical properties (Y/T ratio, U.EL etc.) and the microstructure and secondly the change in mechanical properties by thermal coating treatment. The Y/T ratio and U.EL are affected by the volume fraction of ferrite and the secondary phase, which are changed by thermomechanical control processing (TMCP) conditions. For example, use of dual phase microstructure is very effective for decreasing the Y/T ratio and increasing the U.EL as the pipe. On the other hand, yield strength (YS) rises and the U.EL does not change after coating. The increase in the YS after coating is influenced by the microstructure and TMCP conditions. Resultantly, dependence of the Y/T ratio on the microstructure and TMCP conditions is reduced for line pipes after thermal coating treatment.

Strain Aging Effects in High Strength Line Pipe Materials

2008 ◽  
Author(s):  
Da-Ming Duan ◽  
Joe Zhou ◽  
Brian Rothwell ◽  
David Horsley ◽  
Nick Pussegoda
Keyword(s):  
Mechanical Properties ◽  
Strain Aging ◽  
Mechanical Test ◽  
High Strength ◽  
Parent Material ◽  
Pipe Material ◽  
Aging Effects ◽  
Aging Behavior ◽  
Test Procedures ◽  
Line Pipe

Strain aging behavior can occur in almost all steels, including micro-alloyed steels used in high-strength pipelines. The direct effects of strain aging on mechanical properties can include increased hardness, yield strength and tensile strength, and reduced ductility and toughness. Strain aging may take place in processes where the pipe material experiences thermal cycles, such as coating, welding and in-service heating, and may occur with or without additional plastic strain. The changes of material mechanical properties could seriously challenge the design principles and methodologies, so that these aging effects need to be taken into account. This is especially important for pipelines expected to see deformation-controlled loading conditions. This is not only because the difference in strain aging effects between a weld and the parent material can easily change the strength overmatch condition of the weld, leading to unpredictable girth weld flaw tolerance, but also because the return of Lu¨ders behavior on the stress-strain curves of these materials significantly reduces the pipe buckling load resistance. In addition, any change in fracture resistance due to strain aging may impact the fracture control design practice, particularly if the pipe material may be expected to experience plastic deformation during service. In this paper, a brief review of strain aging behavior in steels is presented, with an emphasis on the effects on the mechanical properties and toughness of three high-strength line pipe steels. Material strain aging mechanical test procedures of three high grade pipes will be described and the test results will be discussed.

Hydrogen Compatibility and Suitability of (Ni)-Cr-Mo High-Strength Low-Alloy Seamless Line Pipe Steels for Pressure Vessels for Hydrogen Storage

2018 ◽  
Author(s):  
Akihide Nagao ◽  
Nobuyuki Ishikawa ◽  
Toshio Takano
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Strength ◽  
Pressure Vessels ◽  
Hydrogen Gas ◽  
Low Alloy Steels ◽  
Pipe Steels ◽  
Line Pipe ◽  
Alloy Steels ◽  
Pressure Hydrogen

Cr-Mo and Ni-Cr-Mo high-strength low-alloy steels are candidate materials for the storage of high-pressure hydrogen gas. Forging materials of these steels have been used for such an environment, while there has been a strong demand for a higher performance material with high resistance to hydrogen embrittlement at lower cost. Thus, mechanical properties of Cr-Mo and Ni-Cr-Mo steels made of quenched and tempered seamless pipes in high-pressure hydrogen gas up to 105 MPa were examined in this study. The mechanical properties were deteriorated in the presence of hydrogen that appeared in reduction in local elongation, decrease in fracture toughness and accelerated fatigue-crack growth rate, although the presence of hydrogen did not affect yield and ultimate tensile strengths and made little difference to the fatigue endurance limit. It is proposed that pressure vessels for the storage of gaseous hydrogen made of these seamless line pipe steels can be designed.

Establishment of Cold Wire Addition Technology® in Multiwire Submerged Arc Welding for Line Pipe Manufacturing to Improve the Weldment Quality

2015 ◽  
Author(s):  
Ramakrishnan Mannarsamy ◽  
S. K. Shrivastava ◽  
Piyush Thakor ◽  
Gautam Chauhan ◽  
S. K. Joshi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Arc Welding ◽  
Welding Process ◽  
High Strength ◽  
Submerged Arc Welding ◽  
Line Pipe ◽  
Cold Wire ◽  
Welding Procedure ◽  
Submerged Arc

For achieving high productivity multiple wire submerged arc welding such as tandem wire, three wires and five wires submerged arc welding was introduced in recent past years. Due to adding of additional wires in a pipe mill faced process difficulties such as controlling the current supply to each wire and further challenges for consumable design in order to give effective slag characteristics and bead shape control at these higher welding speeds and heat inputs. To gain maximum productivity, welding speed must be as fast as possible (in excess of 2 m/min) consistent with reliable high speed wire feeding and the characteristics of the SAW flux considering these factors in determining the balance of heat input, penetration, bead shape, dilution, weld metal chemistry and mechanical properties such as toughness. Steels containing high strength low alloying elements like Manganese, Molybdenum, Titanium and boron have favorable physical properties such as higher subzero toughness, resistance to improve the mechanical properties because of which there is substantial saving in the material. High strength low alloy steels materials are utilized in offshore and onshore at critical services. However, such benefits can be exploited provided these steels can be welded with appropriate development of welding process such as cold wire addition® in multi wires with process controller using WINCC programmer, Z5 version to give better weldments, which will not compromise the integrity, and operating condition. To obtain higher productivity and quality, it is necessary to develop a welding procedure for butt joint of line pipe steels. This paper describes the recent work carried out by Welspun, in this regard to establish the welding procedure using GMAW and submerged arc welding process and evaluation of mechanical properties. Macro and micro structural analysis were also made to characterize the weld metal properties.

The Development of High Strength Hull Steel Plate FH40

2010 ◽  
Vol 44-47 ◽  
pp. 2203-2207
Author(s):  
Xiu Hua Gao ◽  
Lin Xiu Du ◽  
Chun Lin Qiu ◽  
Yong Da Yang
Keyword(s):  
Mechanical Properties ◽  
Strain Aging ◽  
Steel Plate ◽  
High Strength ◽  
National Standard ◽  
Low Carbon ◽  
Controlled Processing ◽  
Hull Steel ◽  
The Impact ◽  
Impact Ductility

High strength hull structural steel plate FH40 has been successfully developed by a 3500mm plate production line. Low-carbon micro-alloying niobium elements and TMCP (thermo-mechanical controlled processing) were employed to refine the grains and improve mechanical properties. This paper investigated the effects of TMCP process on the microstructure and mechanical properties of the rolled FH40 plate. Results indicate that the treatment could significantly improve the mechanical strength and impact toughness of the steel and the impact ductility was further enhanced after strain aging. The properties of plates remarkably satisfied with the requirements of the national standard of china and rules requirements by shipping classification associations.

Determination of Mechanical Properties of High Strength Linepipe

2008 ◽  
Author(s):  
Randy Klein ◽  
Laurie Collins ◽  
Fathi Hamad ◽  
Xiande Chen ◽  
Dengqi Bai
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Tensile Specimen ◽  
Sampling Location ◽  
Noticeable Effect ◽  
Controlled Processes ◽  
Commercial Scale ◽  
The Difference ◽  
Thermal Coating

Commercial scale trials of X100 for Artic gas transmission pipelines have been conducted at IPSCO. Different alloying systems and thermo-mechanical controlled processes have been employed to make X100 coils. The coils were made into spirally welded pipes at IPSCO Spiral Mill in Regina, Canada. These pipes were tested in different conditions, namely as-welded, after hydro-testing, and after thermal coating. Therefore, the effects of as-supplied material and pipe-making processes on the final mechanical properties of pipe were evaluated. It was found that the tensile specimen size and sampling location had a noticeable effect on the testing results. The difference was also observed between the flattened strap specimen and round bar. The influence of the anisotropy of the as-supplied coils and the thermal coating on the final pipe properties will also be presented.

The Short and Long Term Effects of Elevated Temperature on the Mechanical Properties of Line Pipe Steels

2016 ◽  
Author(s):  
Taylor R. Jacobs ◽  
David K. Matlock ◽  
Kip O. Findley ◽  
Laurie Collins
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Tensile Stress ◽  
Strain Aging ◽  
Aging Process ◽  
Elevated Temperatures ◽  
Dynamic Strain ◽  
Line Pipe ◽  
Pipeline Steels ◽  
Strength Grade

The mechanical properties of six industrially produced pipeline steels equivalent to API X52, X60, and X70 specifications were evaluated in the temperature range of 200–350 °C. The steels were tested in uniaxial tension at strain rates of 10−4 and 8 × 10−4 s−1 in the as-received condition and after a low temperature 100 h aging process under a 419 MPa tensile stress. Dynamic strain aging was identified in the tensile data with the observation of serrated yielding, minima in ductility and maxima in ultimate tensile strength with respect to temperature. In addition to minima in ductility, higher strength grade steels exhibited maxima in ductility at high temperatures and greater amounts of strengthening compared to the lower strength grade, both which could be attributed to the precipitation of carbides or nitrides during tensile deformation. The low temperature aging process resulted in increased yield strength due to static strain aging, slight changes to ultimate tensile stress and, no observable change in ductility. Thus, based on the results discussed it is suggested that pipeline steels can be designed based on room temperature tensile properties, using established corrections for such properties at elevated temperatures.

Development of Modern High Strength Heavy Plates for Linepipe Applications

2012 ◽  
Author(s):  
Heike Meuser ◽  
Florian Gerdemann ◽  
Fabian Grimpe ◽  
Charles Stallybrass
Keyword(s):  
Mechanical Properties ◽  
High Pressures ◽  
Large Diameter ◽  
High Strength ◽  
Alternative Methods ◽  
Accelerated Cooling ◽  
Processing Conditions ◽  
Line Pipe ◽  
Heavy Plate ◽  
Shear Area

High strength linepipe steels have to fulfil increasing property demands in modern pipeline applications. The transport of large gas volumes at high pressures from remote areas to the market is achieved in the most economical way by large diameter pipelines. For the last 30 years, high strength heavy plates for pipes and pipe bends were developed and produced at Salzgitter Mannesmann Grobblech. These products were steadily improved for example in terms of toughness and fracture behaviour at low temperatures. This is a strong focus of materials development around the world. Modern high-strength heavy plates used in the production of UOE pipes are generally produced by thermomechanical rolling followed by accelerated cooling (TMCP). The combination of high strength and high toughness of these steels is a result of the bainitic microstructure realised by TMCP and are strongly influenced by the rolling and cooling conditions. This paper gives an overview of the development of high strength plates for line pipe application at Salzgitter Mannesmann Grobblech. From comparably thin-walled X80 plates with no or medium DWTT requirements to recent requirements for approx. 28 mm thick X80 plates with requirements of 75/85% shear area fraction at −30°C and more than 250 J Charpy energy at −40°C the development work and the result of the last five years are described and presented. Classical light-optical characterisation of the microstructure of these steels is at its limits because the size of the observed features is too small to allow reliable quantitative results. Therefore Salzgitter Mannesmann Grobblech and Salzgitter Mannesmann Forschung (SZMF) developed alternative methods with the aim of a quantification of microstructure features and a correlation of those with the mechanical properties and processing conditions. In several investigations, the information is related to the mechanical properties of the plate material. It was found that a variation of the processing conditions has a direct influence on parameters that are accessible through the EBSD method and correlates with mechanical properties. The detailed correlations vary depending on steel grade and TMCP strategy. The results have to be carefully interpreted and help understanding the connection between processing and properties. Consequently this can be used as valuable input for the definition of the processing window for heavy plate production with optimized properties.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

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