Effect of Welding Parameters on the Size of Heat Affected Zone of Submerged Arc Welding

2000 ◽  
Vol 15 (5) ◽  
pp. 649-666 ◽  
Author(s):  
C. S. Lee ◽  
R. S. Chandel ◽  
H. P. Seow
Keyword(s):  
Heat Affected Zone ◽  
Arc Welding ◽  
Submerged Arc Welding ◽  
Welding Parameters ◽  
Submerged Arc

Influence of Thermal Simulated and Real Tandem Submerged Arc Welding Process on the Microstructure and Mechanical Properties of the Coarse Grained Heat Affected Zone

2011 ◽  
Vol 110-116 ◽  
pp. 3191-3198
Author(s):  
Sadegh Moeinifar
Keyword(s):  
Grain Boundaries ◽  
Heat Affected Zone ◽  
Heat Input ◽  
Arc Welding ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Rolled Plate ◽  
Arc Welding Process ◽  
Submerged Arc ◽  
Tandem Submerged Arc Welding

The high-strength low-alloy microalloyed steel was procured as a hot rolled plate with accelerated cooling. The Gleeble thermal simulated process involved heating the steel specimens to the peak temperature of 1400 °C, with constant cooling rates of 3.75 °C/s and 2 °C/s to room temperature. The four-wire tandem submerged arc welding process, with different heat input, was used to generate a welded microstructure. The martensite/austenite constituent appeared in the microstructure of the heat affected zone region for all the specimens along the prior-austenite grain boundaries and between bainitic ferrite laths. The blocky-like and stringer martensite/austenite morphology were observed in the heat affected zone regions. The martensite/austenite constituents were obtained by a combination of field emission scanning electron microscopes and image analysis software The Charpy absorbed energy of specimens was assessed using Charpy impact testing at-50 °C. Brittle particles, such as martensite/austenite constituent along the grain boundaries, can make an easy path for crack propagation. Similar crack initiation sites and growth mechanism were investigated for specimens welded with different heat input values.

Development of Exothermic Flux for Enhanced Penetration in Submerged Arc Welding

2020 ◽  
Vol 19 (01) ◽  
pp. 131-146
Author(s):  
Aditya Kumar ◽  
Kulwant Singh
Keyword(s):  
Mathematical Model ◽  
Arc Welding ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
Graphical Form ◽  
Welding Parameters ◽  
Weld Penetration ◽  
Agglomeration Process ◽  
Arc Welding Process ◽  
Submerged Arc

An exothermic flux for submerged arc welding process has been developed which is capable of enhancing weld penetration of the joint. For this purpose, thermit mixture in different proportions (20% and 40%) has been added to the parent flux by agglomeration process. Beads on plate were deposited using parent and developed exothermic fluxes for a comparative study. EH14 filler wires in combination with parent and exothermic fluxes were used in this investigation. The effects of welding parameters and exothermic flux on weld penetration were investigated and the results have been presented in this paper. It has been found that the penetration increases from 2.95 to 3.51[Formula: see text]mm with 40% thermit mixture addition to the parent flux. It is further observed that penetration increases with increase in the amount of thermit mixture added. A mathematical model has been developed to predict weld penetration or select suitable welding parameters to obtain the desired penetration. The significance of coefficients was tested using Student’s [Formula: see text]-test and the adequacy of developed model was tested using [Formula: see text]-test. The effects of various parameters on penetration have been presented in graphical form for better understanding.

Feasibility Studies on the Modeling and Evaluation of Residual Stresses in Arc Welded Butt Joints

2006 ◽  
Author(s):  
K. Satyambabu ◽  
N. Ramachandran
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Arc Welding ◽  
Thermal Loading ◽  
Submerged Arc Welding ◽  
Pressure Vessels ◽  
Welding Parameters ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Submerged Arc

Many important engineering applications such as nuclear reactors, ships, pipes and pressure vessels are shell-like structures made with weldments. For such a structure, a major problem is the development of residual stress and distortion due to welding. Residual stresses in weldments significantly affect stress corrosion cracking, hydrogen-induced cracking and fatigue strength in welded structures. As-welded components generally have certain amount of residual stresses caused by the application of intense heat or thermal loading at the weld joint, formed due to non-uniform cooling rates at different points in the weld metal and heat affected zones. Presence of residual stresses in a component is detrimental as they may lead to failure below the design stress value and also affect many important properties including the life of a welded component. Welding induced residual stresses can significantly increase the fracture driving force in a weldment and also contribute to brittle fracture. The thermal cycle imposed on any welded object causes thermal expansions and contractions which are not uniform. Quantitative measurement of residual stresses is essential to take remedial measures such as change in the welding technique, optimizing welding parameters (heat input, electrode diameter etc,), change in the weld groove design and post-weld heat treatment for minimizing the residual stresses. Residual stress measurements after post-weld treatment would also ensure the adequacy of stress relief treatment. To have an investigation into these aspects, residual stresses due to Manual Metal Arc Welding and Submerged Arc Welding were measured nondestructively with Ultrasonic technique. Residual stress distribution for Shielded Metal Arc Welding and Submerged Arc Welding were compared and the present studies emphasized, that Shielded Metal Arc Welding gave higher compressive stresses than Submerged Arc Welding. Further, to substantiate the studies, commercial finite element analysis software ANSYS 5.6 was used for modeling of manual metal arc welded joint. The results obtained by ANSYS were compared with those by Ultrasonic method.

Development of Welding Procedures for X90-Grade Seamless Pipes for Riser Applications

2012 ◽  
Author(s):  
Hiroyuki Nagayama ◽  
Masahiko Hamada ◽  
Mark F. Mruczek ◽  
Mark Vickers ◽  
Nobuyuki Hisamune ◽  
...  
Keyword(s):  
Weld Metal ◽  
Arc Welding ◽  
Mechanical Test ◽  
Welding Process ◽  
High Strength ◽  
Submerged Arc Welding ◽  
Welding Parameters ◽  
Flux Cored Arc Welding ◽  
Welding Procedure ◽  
Submerged Arc

Ultra-high strength seamless pipes of X90 and X100 grades have been developed for deepwater or ultra-deepwater applications. Girth welding procedure specifications (WPSs) should be developed for the ultra-high strength pipes. However, there is little information for double jointing welding procedure by using submerged arc welding process for high strength line pipes. This paper describes mechanical test results of submerged arc welding (SAW) and gas shielded flux cored arc welding (GSFCAW) trials with various welding consumables procured from commercial markets. Welds were then made with typical welding parameters for riser productions using high strength X90 seamless pipes. The submerged arc weld metal strength could increase by increasing alloy elements in weld metal. The weld metal with CE (IIW) value of 0.74 mass% achieved fully overmatching for the X90 pipe. The weld metal yield strength (0.2% offset) was 694 MPa, and the ultimate tensile strength was 833 MPa. It was also confirmed that the reduction of boron in weld metal can improve low temperature toughness of high strength weld metal. Furthermore, it was confirmed that the HAZ has excellent mechanical properties and toughness for riser applications. In this study GSFCAW procedures were also developed. GSFCAW can be used for joining pipe and connector material for riser production welding. The weld metal with a CE (IIW) value of 0.54 mass% could meet the required strength level for X90-grade pipe as specified in ISO 3183. Cross weld tensile testing showed that fractures were achieved in the base metal. Good Charpy impact properties in weld metal and HAZ were also confirmed.

Numerical Analysis of Microstructure and Residual Stress in the Weld Zone of Multiwire Submerged Arc Welding

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Enlin Yu ◽  
Yi Han ◽  
Haixiang Xiao ◽  
Ying Gao
Keyword(s):  
Residual Stress ◽  
Temperature Measurement ◽  
Arc Welding ◽  
Large Diameter ◽  
Weld Zone ◽  
Submerged Arc Welding ◽  
Welding Parameters ◽  
Welding Quality ◽  
Welding Temperature ◽  
Submerged Arc

As oil and gas pipelines develop toward large throughput and high pressure, more and more attention has been paid to welding quality of oil pipelines. Submerged arc welding is widely applied in manufacturing of large-diameter welded pipes, and the welding quality has an impact on pipeline safety. With a multiwire submerged arc welding test platform and real-time temperature measurement system, temperature measurement has been done for multiwire submerged arc welding process with and without flux coverage, respectively. As a result, thermal cycling curves in both cases have been obtained, and convection and radiation coefficients of flux-covered X80 pipeline steel in air-cooled environment have been corrected. By using sysweld software, a finite-element computational model was set up for microstructure and residual stress in the weld zone of multiwire longitudinal submerged arc welding. Comparative experiment has been done to obtain welding temperature field with relatively high accuracy. Calculation and analysis of residual stress versus preheat residual stress decreased with increasing preheat temperature up to 100 °C, meanwhile content of bainite in microstructure fell, facilitating reduction in residual stress to some extent. This study provides quantitative reference for further optimization of welding parameters and improvement in weld mechanical properties.

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