Influence of Steel Chemistry and Field Girth Welding Procedure on Performance of API X70 Line Pipe Steels

2020 ◽  
Author(s):  
Mohsen Mohammadijoo ◽  
Laurie Collins ◽  
Muhammad Rashid ◽  
Muhammad Arafin
Keyword(s):  
Welding Process ◽  
Strain Analysis ◽  
Image Correlation ◽  
Shielded Metal Arc Welding ◽  
Line Pipe ◽  
Factors Affecting ◽  
Metal Arc Welding ◽  
Girth Welding ◽  
Welding Procedure ◽  
Haz Toughness

Abstract Owing to recent concerns regarding pipeline field girth weld performance, particularly heat affected zone (HAZ) softening and toughness, EVRAZ North America has initiated a research program to evaluate the response of API grade line pipe to the current field girth welding practices. In particular, this study aims to elucidate the role of steel alloy design as well as the welding procedure on field girth weld and HAZ properties. This understanding is critical to balance the detrimental effects of HAZ softening on the overall joint strength against factors affecting HAZ toughness. A selection of several different steels with different levels of alloying elements, Ceq and Pcm have been subjected to welding trials to assess the effects of chemistry on joint performance. Furthermore, an analysis on the effect of welding process parameters on the joint properties has been made. The welds, fabricated via a manual shielded metal arc welding (M-SMAW) process, were evaluated in terms of toughness, local vs global strain distribution during tensile testing using digital image correlation (DIC) technique, and hardness contour mapping of the weld and HAZ regions. The results explicitly show that the extent of HAZ softening decreased as the amount of Mo, Mn, Ti/N and Ceq increased. However, this alloying addition resulted in a detrimental effect on the HAZ toughness, particularly towards the cap and fill passes. The HAZ softening increased as the inter-pass temperature and the welding heat input increased. In addition, the strain analysis confirmed the weld passes towards the root/hot passes are more prone to HAZ softening compared with the upper cap and fill passes.

Strategies for Controlling Welding Fumes at the Source - A Review

2014 ◽  
Vol 592-594 ◽  
pp. 2539-2545 ◽  
Author(s):  
Sreejith Mohan ◽  
S.P. Sivapirakasham ◽  
P. Bineesh ◽  
K. K. Satpathy
Keyword(s):  
Arc Welding ◽  
Control Strategies ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Detailed Knowledge ◽  
Welding Fumes ◽  
Shielded Metal Arc Welding ◽  
Factors Affecting ◽  
Metal Arc Welding ◽  
New Research

Exposure to welding fumes and its related hazards has always been a matter of serious concern. The mass and composition of fumes from welding depends on several factors. A detailed knowledge of these factors is necessary for understanding the mechanism of fume formation and developing suitable control strategies. This paper gives a literature overview on the various factors affecting welding fumes and strategies for controlling it. The paper focus on types of welding process like Manual Metal Arc Welding (MMAW) or Shielded Metal Arc Welding (SMAW), Gas Metal Arc Welding (GMAW), Flux Core Arc Welding (FCAW), Gas and Tungsten Arc Welding (GTAW). The research in the area of controlling fumes at the source has grown rapidly recently. Still, effective methods have hardly been explored. Improving arc stability by addition of materials with low ionization potential to the welding electrode lead to promising new research directions.

scholarly journals Evaluation of the quality of the shielded metal arc welding process using speckle interferometry

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Felipe Maia Prado ◽  
Daniel José Toffoli ◽  
Sidney Leal Da Silva
Keyword(s):  
Arc Welding ◽  
Speckle Pattern ◽  
Welding Process ◽  
Time History ◽  
Speckle Interferometry ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Properties Of Materials ◽  
Arc Welding Process

Speckle, which is a branch of optics that studies the interference pattern caused by the incidence of coherent light in a material’s surface, has some optical techniques and methods that can be successfully applied to determine properties of materials. In this work we used the method called THSP, Time History Speckle Pattern, in samples made of AISI 1020 carbon steel that were submitted to the shielded metal arc welding (SMAW) process, with the objective of identifying (qualitatively) the level of irregularity on its welded surface, by comparing these samples with a default sample, made with the same material. The technique of spekle by reflection was used for data collection. The results showed quantitative diferences between the default welded sample and the other samples, and there are good perspectives that speckle can be applied to determine the quality of the welding process, since the results showed more accuracy than visual inspection.  

A Study of Software Approach for Predicting Weld Bead Geometry in Shielded Metal Arc Welding (SMAW) Process

2014 ◽  
Vol 554 ◽  
pp. 386-390
Author(s):  
C.W. Mohd Noor ◽  
Manuhutu Ferry ◽  
W.B. Wan Nik
Keyword(s):  
Arc Welding ◽  
Welding Process ◽  
Weld Bead ◽  
Bead Geometry ◽  
Shielded Metal Arc Welding ◽  
Depth Of Penetration ◽  
Weld Bead Geometry ◽  
Bead Width ◽  
Real Process ◽  
Metal Arc Welding

The prediction of the optimal weld bead width is an important aspect in shielded metal arc welding (SMAW) process as it is related to the strength of the weld. This paper focuses on investigation of the development of the simple and accurate model for prediction of weld bead geometry. The experiment used welding current, arc length, welding speed, welding gap and electrode diameter as input parameters. While output parameters are bead width, depth of penetration and weld reinforcement. A number of 33 mild steel plate specimens had undergone the SMAW welding process. The experimental data was used to develop mathematical models using SPSS software. The actual and predicted values of the weld bead geometry are compared. The proposed models shows positive correlation to the real process.

scholarly journals Shielded Metal Arc and Thermite Welding Effect to Residual Stress, Hardness and Crack of R54-Rail Weld Joint

2020 ◽  
Vol 55 (4) ◽  
Author(s):  
Yurianto ◽  
Gunawan Dwi Haryadi ◽  
Sri Nugroho ◽  
Sulardjaka ◽  
Susilo Adi Widayanto
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Arc Welding ◽  
Welding Process ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Crack Susceptibility

The heating and cooling at the end of the welding process can cause residual stresses that are permanent and remain in the welded joint. This study aims to evaluate the magnitude and direction of residual stresses on the base metal and heat-affected zone of rail joints welded by the manual shielded metal arc and thermite welding. This research supports the feasibility of welding for rail. The material used in this study is the R-54 rail type, and the procedure used two rail samples of one meter long each, welded using manual shielded metal arc welding and thermite welding. The base metal and heat-affected zone of the welded joints were scanned with neutron ray diffraction. The scan produces a spectrum pattern and reveals the direction of the residual stress along with it. We found the strain value contained in both types of welded joints by looking at the microstrain values, which we obtained using the Bragg equation. The results show that the magnitude and direction of the residual stress produced by manual shielded metal arc welding and thermite welding are not the same. Thermite welding produces lower residual stress (lower crack susceptibility) than manual shielded metal arc welding. The melt's freezing starts from the edge to the center of the weld to create random residual stresses. The residual stress results of both the manual shielded metal arc welding and thermite welding are still below the yield strength of the base metal.

scholarly journals Performance Analysis of Chromium Carbide Overlay in Coal Nozzle Tip for Utility Boilers

2020 ◽  
Vol 9 (3) ◽  
pp. 2122-2127
Keyword(s):  
Life Cycle ◽  
Elevated Temperature ◽  
Chromium Carbide ◽  
Surface Hardness ◽  
Welding Process ◽  
Impact Angle ◽  
Test Surface ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Arc Welding Process

Coal Nozzle Tip substrates are laid with chromium carbide alloy overlay to improve the performance life cycle of the component in power boiler. Overlay with hard faced materials exhibits better erosion / wear resistance of the components. Nozzle tips are located in front of the fire ball and gets heated up to 650 ºC due to radiations. The purpose of the investigation is to evaluate the performance of chromium carbide over lay in terms of life cycle. The Chromium rich tubular electrode was used to overlay on plate SA 240 type 309S substrate by Shielded Metal Arc Welding process. Test specimens were prepared for SEM/EDAX, microstructure analysis, hardness and jet erosion test. Surface hardness and jet erosion tests were carried out on hard faced surfaces at elevated temperature 600 ºC and 700 °C. Test results were analyzed and found that the Chromium carbide overlay resulted with low hardness and high erosion at elevated temperature with steeper impact angle.

scholarly journals Magnetic Field Effects on 4G Positions in Shielded Metal Arc Welding Process

2020 ◽  
Vol 9 (3) ◽  
pp. 694-703 ◽  
Keyword(s):  
Magnetic Field ◽  
Arc Welding ◽  
Molten Pool ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Butt Joint ◽  
Low Carbon ◽  
Magnetic Field Effects ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding

With the advancement of welding techniques, Arc-welding is one of the most commonly and widely used welding technique for variety of purposes. The underside of welding to be performed makes the molten pool going downward because of gravity vector pulling affects the molten pool. The main purpose of this study is to study how the molten of electrode produced reduce on going downward and produce a good root fusion in overhead position of welding in single V-butt joint with the help of magnetic field on the workpiece. The study of magnet characteristic which includes thebehaviour of molten pool toward magnetic field, the macrostructure and microstructure and its strength should be carried out. Each magnet strength has their own characteristics that affects toward weldment on base metal.As a result, it can be concluded that having a magnetic field applies on base metal A36 low carbon steel may reduce the molten pool from going downward. The selection of a correct magnet strength and welding process may produce good and quality weldment especially in terms of its weld properties and geometry.

ANALISA KEKUATAN MEKANIS SAMBUNGAN LAS KAMPUH V TUNGGAL DAN V GANDA PADA BAJA KARBON RENDAH DENGAN PROSES PENGELASAN SMAW

2021 ◽  
Vol 12 (2) ◽  
pp. 103
Author(s):  
Sudarsono Sudarsono ◽  
Hidayat Hidayat ◽  
Aminur Aminur ◽  
Sarwo Pranoto ◽  
Prinob Aksar
Keyword(s):  
Tensile Strength ◽  
Bending Strength ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Low Carbon ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding

Welding is one of the methods widely used in the joining of metals for structural elements. One of the factors that influence the strength of welded metals is types of welding joints. Suitability of the type of welding joint with geometries of base metals is required to obtain welded metal products with optimum properties. In this study an attempt is made to investigate mechanical properties of welded metals with two different types of joints (single-V and double-V) using the shielded metal arc welding (SMAW) process. Low carbon steel with bevel angle of 60° was used in this study. Welding process was performed using current of 70 A with a constant welding speed. The flexural properties and uniaxial tensile properties are studied by three-point bending test and uniaxial tensile test respectively. Test results show that the tensile strength and the bending strength of single-V specimens is 521.64 N/mm2 and 525.11 N/mm2 respectively. In addition, the tensile strength and the bending strength of double-V specimens is 517.33 N/mm2 and  504.24 N/mm2 respectively

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