Experimental Research on Modern Methods of Welding Pipelines Using Base Materials X60 and X70

2014 ◽  
Vol 216 ◽  
pp. 298-303
Author(s):  
Camelia Maria Hanea ◽  
Radu Iovanas ◽  
Ionut Claudiu Roată ◽  
Alexandru Pascu
Keyword(s):  
Experimental Research ◽  
Fracture Strength ◽  
Welded Joints ◽  
Weld Bead ◽  
Automatic Welding ◽  
Base Materials ◽  
Modern Methods ◽  
Welding Procedure

The aim of the research is to highlight the properties of the welded joints of the steels that are used for mains X60 and X70. X60 and X70 steels were welded by automatic welding procedure (STT) at the root and also by automatic MIG procedure for the filling layers. Thereby an increase between 6 15 [%] of the weld bead hardness was obtained in the case of the X 60 steel welding. An increase of bead fracture strength was also noticed from 570 [N/mm2] X 60 steel to 646 [N/mm2] X70 steel.

scholarly journals The influence of manual metal arc multiple repair welding of long operated waterwall on the structure and hardness of the heat affected zone of welded joints

2017 ◽  
Vol 62 (1) ◽  
pp. 327-333 ◽  
Author(s):  
J. Pikuła ◽  
M. Łomozik ◽  
T. Pfeifer
Keyword(s):  
Heat Affected Zone ◽  
Welded Joints ◽  
Arc Welding ◽  
Power Plants ◽  
Welded Joint ◽  
Weld Bead ◽  
Boiler Steel ◽  
Metallographic Examination ◽  
Metal Arc Welding ◽  
High Degree

Abstract Welded installations failures of power plants, which are often result from a high degree of wear, requires suitable repairs. In the case of cracks formed in the weld bead of waterwall, weld bead is removed and new welded joint is prepared. However, it is associated with consecutive thermal cycles, which affect properties of heat affected zone of welded joint. This study presents the influence of multiple manual metal arc welding associated with repair activities of long operated waterwall of boiler steel on properties of repair welded joints. The work contains the results of macro and microscopic metallographic examination as well as the results of hardness measurements.

scholarly journals Strain Capacity of Girth Welded Joints in HSAW Pipes

2017 ◽  
Author(s):  
Koen Van Minnebruggen ◽  
Stijn Hertelé ◽  
Wim De Waele
Keyword(s):  
Welded Joints ◽  
Structural Integrity ◽  
Tensile Load ◽  
Tensile Loading ◽  
Experimental Result ◽  
Large Strains ◽  
Automatic Welding ◽  
Strain Capacity ◽  
Axial Tensile ◽  
Welding Processes

The general aim of a recently finalized European project, i.e. EU RFCS SBD-Spipe, is to generate specific know-how concerning the development and possible use of spirally welded pipes for demanding applications. The demanding applications relate especially to structural integrity issues, both onshore and offshore, requiring good performance under application of large strains resulting in buckling, collapse and/or tensile loading. The outcome of this project can also be used as technical basis for improving standards and guidelines, that address design and safety of spirally welded pipelines. The contribution of Ghent University to this project focusses on the aspects of tearing resistance, defect tolerance and strain capacity of girth welded joints subjected to remote axial tensile load. A numerical and experimental approach is used for the assessment of flaw tolerability and strain development upon tensile loading. Spiral pipes of steel grade API-5L X70 with 36” and 48” diameters have been girth welded using both a manual and semi-automatic welding processes. Curved wide plate specimens have been extracted from the pipes and artificial weld defects have been introduced. The specimens have been loaded in tension up to failure at a temperature of −10°C. This paper reports on the experimental result of a series of curved wide plate tests.

Evaluating the fracture strength of welded joints based on their limit states under high-cycle stresses

2012 ◽  
Vol 47 (8) ◽  
pp. 553-561
Author(s):  
Mindaugas Leonavičius ◽  
Rimantas Stonkus ◽  
Romualdas Kliukas ◽  
Gediminas Petraitis
Keyword(s):  
Fracture Strength ◽  
Welded Joints ◽  
Limit States

Fatigue Crack Propagation Limit Curves for S690QL and S960M High Strength Steels and their Welded Joints

2018 ◽  
Vol 1146 ◽  
pp. 44-56 ◽  
Author(s):  
János Lukács ◽  
Ádám Dobosy ◽  
Marcell Gáspár
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Propagation ◽  
Crack Growth ◽  
Fatigue Crack Propagation ◽  
Welded Joints ◽  
High Strength Steels ◽  
High Strength ◽  
Base Materials ◽  
Propagation Limit

The objective of the paper is to present the newest results of our complex research work. In order to determination and comparison of the fatigue resistance, fatigue crack growth tests were performed on different grades of S690QL quenched and tempered, and S960TM thermomechanically rolled high strength steels.15 mmand30 mmthick base materials were used for our investigations. Welded joints were made from these base materials, using gas metal arc welding with matching, overmatching, and undermatching filler metals. In the paper, the performance of the welding experiments will be presented, especially with the difficulties of the filler material selection; along with the results of the fatigue crack growth examinations executed on the base materials and its welded joints. Statistical aspects were applied both for the presenting of the possible locations of the cracks in the base materials and the welded joints and for the processing of the measured data. Furthermore, the results will be compared with each other, and the possibility of derivation of fatigue crack propagation limit curves will be referred.

Equal Resistant to Wear Blades Used in Rough Exploitation Conditions

2018 ◽  
Vol 1146 ◽  
pp. 22-26
Author(s):  
Daniel Tihanov Tanasache ◽  
Daniela Dinica ◽  
Emilia Florina Binchiciu ◽  
Horia Binchiciu
Keyword(s):  
Working Conditions ◽  
Mechanical Fatigue ◽  
Base Materials ◽  
Wear Protection ◽  
Welded Structure ◽  
Protection Systems ◽  
Resistance To Wear ◽  
Low Alloyed Steel ◽  
Welding Procedure ◽  
Self Protection

The paper presents representative aspects of the blades and the characterisation of excavator blades, namely frontal loader in the quall resistance to wear version. In exploitation the active surfaces of the blades are subjected to wear through abrasion under high and medium pressure, combined with mechanical fatigue with variable cycles. Retiring the blades is determined by significant degradation of the side zones. The solution developed in order to confront the mentioned phenomena is of modular type, namely equipping the blades with intelligent protection and self-protection systems to wear, which are deposited by cladding with welding on the supports. The blades support is made out of low alloyed steel, which have a controlled hardness and are micro alloyed with boron. The rods used to develop the wear protection systems are type Fe-25%Cr-4%W-Ti-V-La which deposit layers that have a minimum hardness of 55HRC. The challenges solved are related to welding compatibility, in working conditions, of the base materials and the welding ones, through manual electric welding procedure and respective deformation due to residual tensions in the welded structure.

scholarly journals The study of the ferroconcrete beams with thrust on the foil bearings during short-term dynamic loading

2020 ◽  
Vol 315 ◽  
pp. 07003
Author(s):  
Oleg Kumpyak ◽  
Daud Galyautdinov
Keyword(s):  
Dynamic Loading ◽  
Experimental Research ◽  
Fracture Strength ◽  
Considerable Increase ◽  
Intensity Increase ◽  
Short Term ◽  
Foil Bearings ◽  
Horizontal Shift ◽  
Power Intensity ◽  
Positive Effect

While designing and maintaining ferroconcrete beam constructions subjected to a short-term dynamic loading, it is necessary to consider the emergence of the thrust reaction; this leads to a considerable increase of durability and fracture strength. It is also necessary to consider the use of foil bearings as the power-intensity increase of the researched constructions. The aim of the experimental research is to expose the reasonability of using foil bearings in thrust constructions. The paper presents the results of the experimental research of ferroconcrete beam constructions with thrust on foil bearings during short-term dynamic loading. The influence of the thrust on the durability, deformability and fracture strength of ferroconcrete constructions during short-term dynamic loading, as well as joint use of foil bearings and limitation of support contour horizontal shift are studied. The results of the research indicate the positive effect of using foil bearings in the constructions with thrust.

Experimental Research on Fatigue Failure for 2219-T6 Aluminum Alloy Friction Stir-Welded Joints

2017 ◽  
Vol 26 (8) ◽  
pp. 3767-3774 ◽  
Author(s):  
Guo-Qin Sun ◽  
Jiang-Pei Niu ◽  
Ya-Jing Chen ◽  
Feng-Yang Sun ◽  
De-Guang Shang ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Failure ◽  
Experimental Research ◽  
Welded Joints ◽  
Friction Stir

Research on the Use of Robotized Tandem MAG Welding in Steel Plates Destined for the Manufacture of Pipelines

2016 ◽  
Vol 1138 ◽  
pp. 133-138 ◽  
Author(s):  
Daniela Maria Iovanas ◽  
Cosmin Toma ◽  
Radu Iovanas
Keyword(s):  
Welded Joints ◽  
Steel Plates ◽  
Mag Welding ◽  
Welding Parameters ◽  
Filler Materials ◽  
Shielding Gas ◽  
Complete Replacement ◽  
Positive Effects ◽  
Welding Head ◽  
Welding Procedure

The performed research focuses on the complete replacement of the pipeline manufacturing process consisting in welding on SAW+MIG / MAG generators with the robotized Tandem MIG / MAG welding procedure, with low energy consumption.The Tandem MAG procedure was experimented on X52 MS steel plates destined for the manufacture of pipelines, measuring 400x150x12 mm, with Y-joints (30o).The welded joints were executed horizontally and unilaterally, with flux bed support, 3 welding seams, using for filler material two wires of the same quality, EN ISO 14341: G 42 4 M G3Si1 (Filcord C), measuring 1.2 mm in diameter, and shielding gas EN ISO 14175 (CORGON 18).The entire technological welding process was carried out in fully robotized, laboratory conditions, using the QIROX -315 welding robot, fitted with Tandem MIG/MAG welding equipment, type QUINTO-GLC 603.The welding seams were executed with the same Tandem MAG welding head, with two wires, taking advantage of the possibility to rotate the welding head so as to obtain welding seams with the wires either positioned one after the other (tandem), or transversally (perpendicular to the welding direction), obtaining, by correlation with the welding speed, optimal linear energies, implicitly, seams of various widths and penetrations.The results of the tests concerning the characterization of the obtained welded joints corresponded to the mechanical – metallographic tests, falling within the ranges provided by the applicable standards.The welding parameters used in the robotized Tandem MAG procedure may lead to remarkable advantages concerning the use of energy and filler metal. Thus, linear energies are about 40% - 45% smaller than in the case of the classical SAW+MIG / MAG process, with positive effects on the mechanical and metallographic characteristics of the welded joints, leading to significant reductions in energy consumption. Furthermore, the use of filler materials (wire, shielding gas) decreases by 10% - 15% as compared to the classical SAW+MIG / MAG process, leading, implicitly, to lower costs.As a consequence of the obtained results, MAG Tandem welding procedure may become an alternative to SAW submerged arc welding and combined SAW and MIG / MAG welding and a classical reference method for the manufacture of pipelines

Long Term Creep Rupture Strength of 9Cr1MoNbV Narrow Gap Welded Joints Improved by Normalizing and Tempering After Welding

2007 ◽  
Author(s):  
Takashi Sato ◽  
Kohji Tamura ◽  
Koichi Mitsuhata ◽  
Ryuichi Ikura
Keyword(s):  
Welded Joints ◽  
Power Plants ◽  
Rupture Strength ◽  
Thermal Power ◽  
High Strength ◽  
Creep Rupture ◽  
Narrow Gap ◽  
Parent Metal ◽  
Welding Procedure

With the increase of steam parameters of coal-fired thermal power plants, high strength 9%Cr steel containing niobium and vanadium became major material in high temperature boiler components. As the microstructure of these steels is tempered martensite, it is known that the softening occurs in HAZ of the weldment. In the creep rupture test of these welded joints the rupture strength is lower than that of the parent metal, and sometimes this reduction of strength is caused by Type IV cracking. To develop an effective method to improve the rupture strength of welded joints, a normalizing-tempering heat treatment after weld was proposed. 9Cr1MoNbV plates with a thickness of 40–50 mm were welded by 10 mm width automatic narrow gap MAG welding procedure using specially modified welding material. After normalizing at 1050C and tempering at 780C, material properties of the welded joints were examined. Microstructure of the HAZ was improved as before weld, and rupture strength of the welded joints was equal to that of the parent metal. The long term rupture strength of the welded joints as confirmed in the test exceeded 30,000 hours. This welding procedure has been applied to the seam weld of boiler hot reheat piping in USC plants successfully.

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