Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2011
Acceptable quality laser-arc hybrid welds can be produced with many different process gas composi... more Acceptable quality laser-arc hybrid welds can be produced with many different process gas compositions, but if the objective is high productivity, low gas costs, a reliable process, and the best quality, the shielding gas composition makes a remarkable difference in the laser-arc hybrid welding of steels. The present paper mostly concentrates on the welding of steel. The gas type used in such processes has a significant influence upon plasma formation, process stability, and the weld bead shape. In this paper, different process gases have been studied in various laserarc hybrid welding processes. The aim of the review is to assess the influence of shielding gases in the production of a weld.
Light metals are widely used in industry and can be joined also by welding. This study investigat... more Light metals are widely used in industry and can be joined also by welding. This study investigates the most important industrial welding processes for joining sheet metals focusing on their possibilities and limitations. The two main difficulties encountered when welding sheet metals are distortion and burn-through. Each of the processes discussed here features characteristics that help mitigate these problems. Beyond the welding process itself, methods commonly employed to improve the quality of thin sheet metal welding include precisely preparing joints for tight fitup, carefully clamping the base materials, using many short and closely spaced tack welds, positioning a (suitable) (copper) backing, precise control of heat input, and welding with the highest possible uniform travel speed. The processes discussed include GMAW, GTAW, PAW, laser welding, electron beam welding, resistance spot welding and FSW. It was ascertained that the possibilities are limited by material thickness, cleanliness of the surface and welding parameters. When knowing the boundaries it is easier to choose a welding method, and it is also motivation for improvements in welding technology.
Dissimilar welding of austenitic stainless steel (ASS) to low-alloy structural steel is widely us... more Dissimilar welding of austenitic stainless steel (ASS) to low-alloy structural steel is widely used in the power generation industry. The formation of brittle martensite and hot cracking susceptibility in the single-phase austenite microstructure are the main concerns related to the metallurgy of this kind of weld. This study investigates the effect of different welding wires and the weaving technique on the quality, microstructure and microhardness of fillet weld joints between AISI 304L austenitic stainless steel and S355MC low-alloy structural steel. Using robotised synergic gas metal arc welding (GMAW), three different filler wires were used to weld specimens with and without weaving. The macrosections of the fillet welds were inspected and the dilution rates and ferrite numbers (FN) measured. The microstructure was also inspected and microhardness values recorded. Porosity was discerned in two weld samples made with the use of weave beads. The measured FNs for all the weldments were very close to estimations from the Schaeffler diagram. The formation of a narrow martensitic band on the ferritic side of the weld metal was detected for most of the specimens. It is concluded that weaving decreased the dilution rate and increased the FN. However, no obvious effect on the microstructure and hardness as a result of using the weaving technique was noticed.
Aluminum alloys are well established as engineering materials for a wide range of applications be... more Aluminum alloys are well established as engineering materials for a wide range of applications because they offer a combination of low weight, high strength, good corrosion resistance, formability and weldability. This paper describes an investigation of the possibilities to reduce some of the defects (e.g. porosity and solidification cracks), and to produce good quality welds when welding Al-Mg-Si alloy profiles EN AW-6005 and EN AW-6063 and Al-Mg alloy wrought plate EN AW-5754 by using mechanized Friction Stir Welding (FSW). Friction Stir Welding (FSW) was used in welding these aluminum alloy profiles and plate in butt joints of thickness of 3mm. An assessment was made regarding the weld bead geometry and the mechanical properties of these alloy weld profiles. Recommendations have been made on suitable welding variables and methods to minimize weld defects often found when welding these Al alloys using the mechanized FSW process.
The development of welding power sources towards new digital devices helps us to get better resul... more The development of welding power sources towards new digital devices helps us to get better results at welding root passes without backing. This study evaluates the quality and productivity of a root pass welding with 5 mm thick austenitic stainless plates by the new modified short arc Gas Metal Arc Welding (GMAW) method together with conventional welding methods. Welding runs were made under different fit-up gaps and the various process parameters were continuously observed for the processes. The modified short arc GMAW techniques offer a number of advantages over the conventional welding methods (GMAW, GTAW and SMAW) when welding root passes from a single side without backing due to the fact that the current mode used in conventional welding methods is not sufficient enough to be used for welding root passes. It was found that 1) a faster welding speed, 2) a higher quality weld without, e.g., a lack of penetration or an excessive root and 3) a narrower Heat Affected Zone (HAZ) can...
In the welding of aluminium 6000 series, hot cracks can easily be produced if the welding conditi... more In the welding of aluminium 6000 series, hot cracks can easily be produced if the welding conditions and welding procedures are not carefully observed. The aim of this study is to find out some of the factors that cause hot cracks theoretically and experimentally and how to minimize or avoid this undesirable outcome when welding 10 mm thick heat treatable wrought aluminium alloys 6005 T6 and 6082 T6 bead-on-plate using 4043 and 5356 alloy filler metal by mechanized TIG and MIG welding processes. The welding process, filler metal composition and preheating temperature have been chosen as the main factors affecting the formation of liquation cracking. A comparison of these welding processes will be made based on heat input (Q), and optimum welding parameters for these extruded profiles will be specified. The influence of different factors on sensitivity to cracking is evaluated by preparing macro and micro photos of the test samples, and Vickers hardness tests were used to examine the...
International Journal of Mechanical and Materials Engineering
The manufacturing industry continues to be challenged by low weight and cost requirements, increa... more The manufacturing industry continues to be challenged by low weight and cost requirements, increase of energy efficiency, improvements of performance and reducing deleterious environmental effects. Aluminium has become an important part of the manufacturing process of automobile, aircraft, shipbuilding and engineering industries. This paper is based on a literature review of thin sheet weldabilities and welding processes possibilities. There are difficulties existing during the welding of thin aluminium alloys specifically associated with heat input which affects weld quality, leading to porosity, cracking, burn-through and distortion defects. Approaches to mitigate these problems have been adopted, such as careful clamping of the workpiece, improved preparation of joints for tight fit–up, advanced control of heat input, and others. Commonly-used welding processes like Gas Metal Arc Welding, Gas Tungsten Arc Welding, Plasma Arc Welding, Laser Beam Welding and Friction Stir Welding s...
Metal industries producing thick sections have shown increasing interest in laser-arc hybrid weld... more Metal industries producing thick sections have shown increasing interest in laser-arc hybrid welding processes because of their clear advantages compared with the individual processes of autogenous laser welding and arc welding. One major benefit of laser-arc hybrid welding is that compared to autogenous laser, welding joints with larger gaps can be welded with acceptable quality. The laser-arc hybrid welding process has good potential to extend the field of applications of laser technology, and provide significant improvements in weld quality and process efficiency in manufacturing applications. The objective of this review is to present a set-up for laser-arc hybrid welding processes and introduce a methodical comparison of the chosen parameters. The research describes the principles, means and applications of different types of laser-arc hybrid welding processes. Based on a review of the current knowledge base, important areas for further research are also identified. The study u...
Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture
Aluminium and its alloys have gained increasing importance in structural engineering due to advan... more Aluminium and its alloys have gained increasing importance in structural engineering due to advantageous properties such as light weight, ease of machining and corrosion resistance. This article presents surface-related challenges facing aluminium welding, specifically weld process limitations and joint limitations. The methodological approach is a critical review of published literature and results based on eight industrial welding processes for aluminium and six joint types. It is shown that challenges such as heat input control, hot cracking, porosity and weldable thickness vary with the process used and that there is no optimal general weld process for all aluminium alloys and thicknesses. A selection table is presented to assist in selection of the optimal process for specific applications. This study illustrates that knowledge of weld limitations is valuable in selection of appropriate weld processes.
Demands for improved productivity, efficiency, and quality pose challenges to the welding industr... more Demands for improved productivity, efficiency, and quality pose challenges to the welding industry. As materials become ever more sophisticated in their chemical composition to provide ever-better functionally specific properties, a more complete and precise understanding of how such materials can be joined for optimal effectiveness and efficiency will become essential. Traditional options for welding will surely evolve, sometimes to provide unimagined capabilities. In addition, totally new methods will almost certainly emerge as evolution of materials gives way to revolution to meet unimagined new designs and design demands. The paper considers process systematization and corresponding advances of constituent technologies, discusses some of the role and future direction of welding technology, welding materials, productivity and efficiency, education and safety having an impact on future growth in welding technology. Analysis of drivers and the key needs of some manufacturing indust...
The Arctic contains about 22% of the world's untapped oil and gas reserves. The facilities re... more The Arctic contains about 22% of the world's untapped oil and gas reserves. The facilities required for exploration of these resources are now being constructed with high strength steels (HSS) and are predominantly joined together by welding technologies. Consequently, there is a need to develop advanced and efficient welding technologies that ensure good weldability and good low-temperature toughness at the HAZ and the weld joints. This paper explores and presents an overview of efficient welding technologies applicable to the construction of HSS Arctic offshore structures. For each selected welding process considered, welding parameter modifications are suggested to ensure weldments are produced with desired qualities and properties, and at a high productivity rate.
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2014
Dissimilar ferrous metal welding using advanced gas metal arc welding processes k ( & 3 c N [ P R... more Dissimilar ferrous metal welding using advanced gas metal arc welding processes k ( & 3 c N [ P R D a b f 5R [ a R 5 a Rev. Adv. Mater. Sci.
ture simplified improves the applicability of robotic welding and provides benefits accruing from... more ture simplified improves the applicability of robotic welding and provides benefits accruing from mass production. The same module can be used in several boat models. The modularity also makes it possible to use the same advanced robot welding fixture for a variety of boat models.
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2011
Acceptable quality laser-arc hybrid welds can be produced with many different process gas composi... more Acceptable quality laser-arc hybrid welds can be produced with many different process gas compositions, but if the objective is high productivity, low gas costs, a reliable process, and the best quality, the shielding gas composition makes a remarkable difference in the laser-arc hybrid welding of steels. The present paper mostly concentrates on the welding of steel. The gas type used in such processes has a significant influence upon plasma formation, process stability, and the weld bead shape. In this paper, different process gases have been studied in various laserarc hybrid welding processes. The aim of the review is to assess the influence of shielding gases in the production of a weld.
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2011
Acceptable quality laser-arc hybrid welds can be produced with many different process gas composi... more Acceptable quality laser-arc hybrid welds can be produced with many different process gas compositions, but if the objective is high productivity, low gas costs, a reliable process, and the best quality, the shielding gas composition makes a remarkable difference in the laser-arc hybrid welding of steels. The present paper mostly concentrates on the welding of steel. The gas type used in such processes has a significant influence upon plasma formation, process stability, and the weld bead shape. In this paper, different process gases have been studied in various laserarc hybrid welding processes. The aim of the review is to assess the influence of shielding gases in the production of a weld.
Light metals are widely used in industry and can be joined also by welding. This study investigat... more Light metals are widely used in industry and can be joined also by welding. This study investigates the most important industrial welding processes for joining sheet metals focusing on their possibilities and limitations. The two main difficulties encountered when welding sheet metals are distortion and burn-through. Each of the processes discussed here features characteristics that help mitigate these problems. Beyond the welding process itself, methods commonly employed to improve the quality of thin sheet metal welding include precisely preparing joints for tight fitup, carefully clamping the base materials, using many short and closely spaced tack welds, positioning a (suitable) (copper) backing, precise control of heat input, and welding with the highest possible uniform travel speed. The processes discussed include GMAW, GTAW, PAW, laser welding, electron beam welding, resistance spot welding and FSW. It was ascertained that the possibilities are limited by material thickness, cleanliness of the surface and welding parameters. When knowing the boundaries it is easier to choose a welding method, and it is also motivation for improvements in welding technology.
Dissimilar welding of austenitic stainless steel (ASS) to low-alloy structural steel is widely us... more Dissimilar welding of austenitic stainless steel (ASS) to low-alloy structural steel is widely used in the power generation industry. The formation of brittle martensite and hot cracking susceptibility in the single-phase austenite microstructure are the main concerns related to the metallurgy of this kind of weld. This study investigates the effect of different welding wires and the weaving technique on the quality, microstructure and microhardness of fillet weld joints between AISI 304L austenitic stainless steel and S355MC low-alloy structural steel. Using robotised synergic gas metal arc welding (GMAW), three different filler wires were used to weld specimens with and without weaving. The macrosections of the fillet welds were inspected and the dilution rates and ferrite numbers (FN) measured. The microstructure was also inspected and microhardness values recorded. Porosity was discerned in two weld samples made with the use of weave beads. The measured FNs for all the weldments were very close to estimations from the Schaeffler diagram. The formation of a narrow martensitic band on the ferritic side of the weld metal was detected for most of the specimens. It is concluded that weaving decreased the dilution rate and increased the FN. However, no obvious effect on the microstructure and hardness as a result of using the weaving technique was noticed.
Aluminum alloys are well established as engineering materials for a wide range of applications be... more Aluminum alloys are well established as engineering materials for a wide range of applications because they offer a combination of low weight, high strength, good corrosion resistance, formability and weldability. This paper describes an investigation of the possibilities to reduce some of the defects (e.g. porosity and solidification cracks), and to produce good quality welds when welding Al-Mg-Si alloy profiles EN AW-6005 and EN AW-6063 and Al-Mg alloy wrought plate EN AW-5754 by using mechanized Friction Stir Welding (FSW). Friction Stir Welding (FSW) was used in welding these aluminum alloy profiles and plate in butt joints of thickness of 3mm. An assessment was made regarding the weld bead geometry and the mechanical properties of these alloy weld profiles. Recommendations have been made on suitable welding variables and methods to minimize weld defects often found when welding these Al alloys using the mechanized FSW process.
The development of welding power sources towards new digital devices helps us to get better resul... more The development of welding power sources towards new digital devices helps us to get better results at welding root passes without backing. This study evaluates the quality and productivity of a root pass welding with 5 mm thick austenitic stainless plates by the new modified short arc Gas Metal Arc Welding (GMAW) method together with conventional welding methods. Welding runs were made under different fit-up gaps and the various process parameters were continuously observed for the processes. The modified short arc GMAW techniques offer a number of advantages over the conventional welding methods (GMAW, GTAW and SMAW) when welding root passes from a single side without backing due to the fact that the current mode used in conventional welding methods is not sufficient enough to be used for welding root passes. It was found that 1) a faster welding speed, 2) a higher quality weld without, e.g., a lack of penetration or an excessive root and 3) a narrower Heat Affected Zone (HAZ) can...
In the welding of aluminium 6000 series, hot cracks can easily be produced if the welding conditi... more In the welding of aluminium 6000 series, hot cracks can easily be produced if the welding conditions and welding procedures are not carefully observed. The aim of this study is to find out some of the factors that cause hot cracks theoretically and experimentally and how to minimize or avoid this undesirable outcome when welding 10 mm thick heat treatable wrought aluminium alloys 6005 T6 and 6082 T6 bead-on-plate using 4043 and 5356 alloy filler metal by mechanized TIG and MIG welding processes. The welding process, filler metal composition and preheating temperature have been chosen as the main factors affecting the formation of liquation cracking. A comparison of these welding processes will be made based on heat input (Q), and optimum welding parameters for these extruded profiles will be specified. The influence of different factors on sensitivity to cracking is evaluated by preparing macro and micro photos of the test samples, and Vickers hardness tests were used to examine the...
International Journal of Mechanical and Materials Engineering
The manufacturing industry continues to be challenged by low weight and cost requirements, increa... more The manufacturing industry continues to be challenged by low weight and cost requirements, increase of energy efficiency, improvements of performance and reducing deleterious environmental effects. Aluminium has become an important part of the manufacturing process of automobile, aircraft, shipbuilding and engineering industries. This paper is based on a literature review of thin sheet weldabilities and welding processes possibilities. There are difficulties existing during the welding of thin aluminium alloys specifically associated with heat input which affects weld quality, leading to porosity, cracking, burn-through and distortion defects. Approaches to mitigate these problems have been adopted, such as careful clamping of the workpiece, improved preparation of joints for tight fit–up, advanced control of heat input, and others. Commonly-used welding processes like Gas Metal Arc Welding, Gas Tungsten Arc Welding, Plasma Arc Welding, Laser Beam Welding and Friction Stir Welding s...
Metal industries producing thick sections have shown increasing interest in laser-arc hybrid weld... more Metal industries producing thick sections have shown increasing interest in laser-arc hybrid welding processes because of their clear advantages compared with the individual processes of autogenous laser welding and arc welding. One major benefit of laser-arc hybrid welding is that compared to autogenous laser, welding joints with larger gaps can be welded with acceptable quality. The laser-arc hybrid welding process has good potential to extend the field of applications of laser technology, and provide significant improvements in weld quality and process efficiency in manufacturing applications. The objective of this review is to present a set-up for laser-arc hybrid welding processes and introduce a methodical comparison of the chosen parameters. The research describes the principles, means and applications of different types of laser-arc hybrid welding processes. Based on a review of the current knowledge base, important areas for further research are also identified. The study u...
Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture
Aluminium and its alloys have gained increasing importance in structural engineering due to advan... more Aluminium and its alloys have gained increasing importance in structural engineering due to advantageous properties such as light weight, ease of machining and corrosion resistance. This article presents surface-related challenges facing aluminium welding, specifically weld process limitations and joint limitations. The methodological approach is a critical review of published literature and results based on eight industrial welding processes for aluminium and six joint types. It is shown that challenges such as heat input control, hot cracking, porosity and weldable thickness vary with the process used and that there is no optimal general weld process for all aluminium alloys and thicknesses. A selection table is presented to assist in selection of the optimal process for specific applications. This study illustrates that knowledge of weld limitations is valuable in selection of appropriate weld processes.
Demands for improved productivity, efficiency, and quality pose challenges to the welding industr... more Demands for improved productivity, efficiency, and quality pose challenges to the welding industry. As materials become ever more sophisticated in their chemical composition to provide ever-better functionally specific properties, a more complete and precise understanding of how such materials can be joined for optimal effectiveness and efficiency will become essential. Traditional options for welding will surely evolve, sometimes to provide unimagined capabilities. In addition, totally new methods will almost certainly emerge as evolution of materials gives way to revolution to meet unimagined new designs and design demands. The paper considers process systematization and corresponding advances of constituent technologies, discusses some of the role and future direction of welding technology, welding materials, productivity and efficiency, education and safety having an impact on future growth in welding technology. Analysis of drivers and the key needs of some manufacturing indust...
The Arctic contains about 22% of the world's untapped oil and gas reserves. The facilities re... more The Arctic contains about 22% of the world's untapped oil and gas reserves. The facilities required for exploration of these resources are now being constructed with high strength steels (HSS) and are predominantly joined together by welding technologies. Consequently, there is a need to develop advanced and efficient welding technologies that ensure good weldability and good low-temperature toughness at the HAZ and the weld joints. This paper explores and presents an overview of efficient welding technologies applicable to the construction of HSS Arctic offshore structures. For each selected welding process considered, welding parameter modifications are suggested to ensure weldments are produced with desired qualities and properties, and at a high productivity rate.
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2014
Dissimilar ferrous metal welding using advanced gas metal arc welding processes k ( & 3 c N [ P R... more Dissimilar ferrous metal welding using advanced gas metal arc welding processes k ( & 3 c N [ P R D a b f 5R [ a R 5 a Rev. Adv. Mater. Sci.
ture simplified improves the applicability of robotic welding and provides benefits accruing from... more ture simplified improves the applicability of robotic welding and provides benefits accruing from mass production. The same module can be used in several boat models. The modularity also makes it possible to use the same advanced robot welding fixture for a variety of boat models.
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2011
Acceptable quality laser-arc hybrid welds can be produced with many different process gas composi... more Acceptable quality laser-arc hybrid welds can be produced with many different process gas compositions, but if the objective is high productivity, low gas costs, a reliable process, and the best quality, the shielding gas composition makes a remarkable difference in the laser-arc hybrid welding of steels. The present paper mostly concentrates on the welding of steel. The gas type used in such processes has a significant influence upon plasma formation, process stability, and the weld bead shape. In this paper, different process gases have been studied in various laserarc hybrid welding processes. The aim of the review is to assess the influence of shielding gases in the production of a weld.
Northern European countries and Russia have growing interest in developing Arctic oil. This paper... more Northern European countries and Russia have growing interest in developing Arctic oil. This paper provides a comprehensive review of European and Russian metals that are used or can be used in Arctic offshore structures. The article examines several groups of steel, such as low carbon, low-alloy, chromium containing steels and stainless steels, and additionally considers aluminium in low-temperature applications. The paper introduces standardized materials and their properties and discusses recent developments. It further describes
practical applications of the presented metals in some recent Arctic offshore projects. The harsh and variable low-temperature Arctic environment imposes considerable demands on metals, and the challenging task of metal selection requires specific knowledge of metal behavior in such conditions.
In the last decades, there is a high interest in the Arctic area mainly due to a large share of n... more In the last decades, there is a high interest in the Arctic area mainly due to a large share of natural resources located there. Most common structures used for oil and gas production are offshore structures and vessels. This paper reviews a wide range of challenges associated with operation in the Arctic area and summarize them in three main groups. Limited experience of Arctic oil and gas projects results in poor alignment of standard requirements for materials and manufacturing processes. Limited data on climate and its variability is demanding high reliability requirement for operations in the Arctic as well as uncertainty about operational conditions. Economic feasibility of oil and gas projects is a critical issue which calls for more efficient materials and fabrication processes. Challenges in each group are reviewed in details and possible solutions are offered.
The paper describes the results of a comparative study of two Finnish and Russian Arctic shipbuil... more The paper describes the results of a comparative study of two Finnish and Russian Arctic shipbuilding thick steel plates. E500 steel plate (TMCP, 25 mm thickness, Ruukki) and F500W steel plate (QT, 35 mm thickness, CRISM Prometey), which are designed for operation in Arctic conditions at temperatures as low as -40ºC and -60ºC, respectively, were tested. The steels were compared in terms of base metal quality and welding performance. Welds and base metal were tested by methods described in Western European and Russian standards; namely, static tension test, Charpy impact test with V-notch, null-ductility (NDT) test, Tkb test (three-point bending) and crack tip opening displacement (CTOD) test. The motivation for this research was to test the ability of Finnish steel plates to meet the requirements of special tests required by the Russian Maritime Register of Shipping, such as Tkb and null-ductility tests. The test results showed good performance for both the Finnish and Russian steels. The steels were found to meet the requirements for Arctic application of both Finnish and Russian standards.
Nowadays researchers are overloaded with scientific information and it is difficult to see the bi... more Nowadays researchers are overloaded with scientific information and it is difficult to see the big picture of existing research in some particular field. Utilization of Big Data tools and instruments can serve as one approach to define trending research topics by analyzing recent and current publications. This paper analyses 12000 welding related articles from Scopus database for ten years period using VOS viewer and Microsoft Excel. The analysis presents the most occurring keywords statically and in time series analysis. The results allow to define trending and emerging topics of welding research and to get an overall picture of the welding research. This work provides welding research insides for both industry and academia.
Welding defects result in failure of the machinery and other negative consequences. Therefore, th... more Welding defects result in failure of the machinery and other negative consequences. Therefore, they need to be detected as they appear to ensure efficient and high-quality production. There is a raising interest in the implementation of sensors to provide highly accurate and robust real-time welding process monitoring. This work describes the four most widely used techniques of welding process monitoring. These monitoring techniques are arc sensors, optical sensors, infrared sensors, and ultrasonic sensors. This work explains their principles of operation: discuss their advantages and limitations and give typical areas of application. Arc sensors, optical sensors, infrared sensors, and ultrasonic sensors are described in detail with the necessary figures and schemes in the first part of the present study. The physical background, the strengths and weaknesses, and real life examples of the sensing techniques are given in this part. The results of the research show that each sensing method has its specific features that can play an important role in certain welding applications. Arc sensors do not require an additional equipment in the welding zone. This is why they can be used where operational space is limited. Optical sensors allow the observation of the weld pool behavior. Infrared sensors can create the temperature profile of the weld. Ultrasonic sensors usually have good resolution and can provide accurate data. This paper will help welding engineers to choose the optimal sensing equipment for a specific industrial application.
This study looks at major destructive and non-destructive techniques used to evaluate weld qualit... more This study looks at major destructive and non-destructive techniques used to evaluate weld quality in modern welding production. This paper presents a general review and explanation of these methods, and implements a more intensive research on destructive methods. Some attention has been paid to find future trends in the development of welding evaluation approaches. This study provides a good foundation for learning and creates awareness among the metal industries to evaluate their productivity and quality in the field of welding.
The International Journal of Advanced Manufacturing Technology, Dec 21, 2014
Extensive industrial use of thick highstrength
steel plates in Arctic shipbuilding calls for
su... more Extensive industrial use of thick highstrength
steel plates in Arctic shipbuilding calls for
submerged arc welding (SAW) processes with higher
deposition rates. One of the most effective ways of
increasing the deposition rate is to increase the number
of welding wires. Although SAW processes with
up to six wires exist, their use is not widespread and
two- or three-wire modifications, which are the focus
of this paper, are the most common approaches. This
paper presents a case study of the development of a
welding procedure for welding of high-strength steel
shipbuilding plates using a three-wire SAW process.
Welding parameters and conditions were evaluated
with the aim of achieving a high-quality weld. Optimal
parameters for 12-mm plate thickness were found
to be: Св-08ГСМТ wire (similar to Mn4Ni1Mo) of
3.2 mm in diameter, single-pass welding, welding flux
48AF-56, I=840 A, U=37 V, Q=5.4 kJ/mm. Optimal
parameters were also found for 16-mm plate for two
pass welding. Testing of the weld joint included a
static tensile strength test, an impact energy test at
different temperatures, a bending test, a low-cycle
fatigue strength test, microstructure examination and
a hardness test. The tests showed satisfactory results
that indicate that the developed welding technique is
applicable for Arctic shipbuilding applications. The
paper provides improved understanding of the welding
technique selection process for Arctic shipbuilding as
well as providing industrially valuable information
about the developed welding technique.
The constantly growing demand for natural resources has made the Arctic region, which holds appro... more The constantly growing demand for natural resources has made the Arctic region, which holds approximately 20% of estimated world oil and gas reserves, an attractive area for exploitation. Since a great variety of ocean-going vessels are used in oil and gas production, ice shrinkage caused by global warming has further encouraged growth in the Arctic offshore and shipbuilding sectors. However, taking into account the harsh Arctic environment, the reliability of offshore structures and ships is of high importance. One of the major factors influencing the reliability of an offshore structure is material selection. The purpose of this paper is to examine how alloying elements influence the low-temperature properties of steels. The paper in particular, looks at Charpy impact test results on steel at low temperatures. The effects of carbon, manganese, sulphur, phosphorus, aluminium, nitrogen, nickel and other alloying elements in the chemical composition of steels are discussed. This paper not only helps the shipbuilding and offshore industries obtain a clear understanding of the effect of alloying elements used in steels for low-temperature service, but also provides recommendations on the amount of alloying elements needed to achieve certain properties.
During the last decades numerous offshore structures for the exploitation of marine oil and gas r... more During the last decades numerous offshore structures for the exploitation of marine oil and gas resources in the Arctic area or areas with similar conditions have been built. These structures demand high level of reliability, therefore repair and maintenance work have to be done properly and regularly. There are two repair areas which are significantly different – structure splash zone and deep water zone. The paper considers manual metal arc welding, TIG welding, MIG/MAG, flux-cored arc welding, friction stir welding and dry spot habitat welding, paying attention to the risks associated with underwater welding as for welder and for the equipment.
In recent decades, the Arctic has been a focus of interest primarily because of its vast natural ... more In recent decades, the Arctic has been a focus of interest primarily because of its vast natural resources. Most structures utilized for oil and gas production are offshore structures and vessels. This paper overviews a range of difficulties connected with operation in the Arctic region and concentrates them on three primary problems. Limited experience of Arctic oil and gas projects has meant unclear standard prerequisites for materials and assembling techniques. Not only deficient information on the climate and its variability, but also uncertainty about operational conditions demands high reliability from operations in the Arctic. Economic feasibility of oil and gas tasks is a critical issue, which calls for more effective materials and manufacture processes. Difficulties in each aspect are evaluated with points of interest and conceivable arrangements are suggested.
Advancements in Intelligent Gas Metal Arc Welding Systems: Fundamentals and Applications presents... more Advancements in Intelligent Gas Metal Arc Welding Systems: Fundamentals and Applications presents the latest on gas metal arc welding which plays a significant role in modern manufacturing industries and accounts for about 70% of welding processes. The importance of advancements in GMAW cannot be underestimated as they can lead to more efficient production strategies, resource savings and quality improvements. This book provides an overview of various aspects associated with GMAW, starting from the theoretical basis and ending with characteristics of industrial applications and control methods. Additional sections cover processes associated with welding and welding control, such as fuzzy logic, artificial neural networks, and others.
Uploads
Papers by Paul Kah
practical applications of the presented metals in some recent Arctic offshore projects. The harsh and variable low-temperature Arctic environment imposes considerable demands on metals, and the challenging task of metal selection requires specific knowledge of metal behavior in such conditions.
steel plates in Arctic shipbuilding calls for
submerged arc welding (SAW) processes with higher
deposition rates. One of the most effective ways of
increasing the deposition rate is to increase the number
of welding wires. Although SAW processes with
up to six wires exist, their use is not widespread and
two- or three-wire modifications, which are the focus
of this paper, are the most common approaches. This
paper presents a case study of the development of a
welding procedure for welding of high-strength steel
shipbuilding plates using a three-wire SAW process.
Welding parameters and conditions were evaluated
with the aim of achieving a high-quality weld. Optimal
parameters for 12-mm plate thickness were found
to be: Св-08ГСМТ wire (similar to Mn4Ni1Mo) of
3.2 mm in diameter, single-pass welding, welding flux
48AF-56, I=840 A, U=37 V, Q=5.4 kJ/mm. Optimal
parameters were also found for 16-mm plate for two
pass welding. Testing of the weld joint included a
static tensile strength test, an impact energy test at
different temperatures, a bending test, a low-cycle
fatigue strength test, microstructure examination and
a hardness test. The tests showed satisfactory results
that indicate that the developed welding technique is
applicable for Arctic shipbuilding applications. The
paper provides improved understanding of the welding
technique selection process for Arctic shipbuilding as
well as providing industrially valuable information
about the developed welding technique.