MAG Method Research Articles

Measuring modal accessibility gap using gridded population and network map platform data

Few studies have calculated the magnitude of the modal accessibility gap between public and private transportation (MAG) by taking into account both population characteristics and time-varying characteristics. To incorporate the aforementioned characteristics, this study computed MAG within each population grid using the anticipated travel time between two grids in real time. Moreover, a representative case study focuses on the MAG in the urban area of Xi'an during three time periods. Research results indicate that the average travel time for private transportation in the study area is significantly lower than that of public transportation. Further, the subway line has an obvious impact on improving MAG. In addition, the development of public transportation in the peripheral regions lags behind that of the city center, and the subway network is inadequately serviced. As a result of utilizing the MAG method presented in this paper, the problem related to urban transportation planning can be addressed by incorporating both the population and time-varying factors. At the end of the paper, the limitations and future works are discussed.

Mapping structural lineaments using the edge filters of the potential field: a case study of the Rizhao–Lianyungang area, East China

Background: Edge enhancement plays an important role in potential field data processing and interpretation, which facilitate regional tectonic studies, mineral and energy exploration. This is because edges on potential field often indicate linear geological structures such as fractures, edges of geological bodies and so on. With the development of meticulous edge enhancement on potential field, the phenomenon of false edges caused by the associated anomalies when detect ing edges from magnetic field cannot be ignored.Methods: Aiming at this problem, we proposes a modified magnetic edge detection method (SP Mag) based on the second order spectral moment. This method has been tested on both synthetic and field data. The synthetic test show that SP Mag cannot only balanced edges no matter from strong or weak anomalies, but also eliminates those false edges caused by the associated anomalies in magnetic field, which provide more effective information for subsequent interpretation.Results: We apply this new method to the RTP aero magnetic field and gravity field of Rizhao Lianyungang area. The lineaments recognized by the SP Mag method correspond well with geologic structures through comparing with geological maps.Discussion: The results illustrate the usefulness of the method for potential field interpretation. Furthermore, more geological and geophysical data should be still combined for comprehensive interpretation in the actual interpretation, though the SP Mag method can recognize lineaments effectively.

An experimental examination of the effect of temperature distributions in different welding sorting of the part transmitting thrust in front loader of tractors by means of MAG method on displacements

In this study, temperatures of samples welded by 3 different welding sorting has been measured and displacements occurring on the part after wielding have been determined and an experimental comparison has been made in this regard. The welded part belongs to the front loader used in tractors. Material of the mod-el is S355j2+N. In the experimental study, 3 samples have been welded for each process. In Process 1, welding lines have been observed outside to inside, in Pro-cess 2 inside to outside, and in Process 3 from right to left. For all parts, welding parameters and welding speed have been fixed. Welding manufacture and cool-ing processes have lasted 3000 seconds in total. 4 points have been determined in order to measure the temperature of the part during the experiment. For deter-mination of displacement amount, sample parts have been measured by means of 3-dimensional laser measuring device before and after welding. When results of experiment are examined, it has been observed that temperatures curves are similar in processes no. 1 and 3; and the process has been completed by lower temperature in process no. 2. The highest temperatures measured in processes 1, 2 and 3 are respectively as 380oC, 272oC ve 310oC. Displacements of circular and cylindric points are respectively as 2.17 mm, 1.22 mm, 2.12mm. Maximum displacements of the surfaces are as 0.40 mm, 0.41 mm, 0.80 mm for process 1; as 0.10 mm, 0.28 mm, 0.83 mm for process 2; and as 0.71 mm 0.77 mm 1.39 mm for process 2. It has been concluded that process no. 2 has lower temperatures and less displacements. Less amount of displacement or distortion provides use of parts without applying correction afterwards, and eliminates surplus work-manship and time loss.

Hybrid Welding (Laser-Electric Arc MAG) of High Yield Point Steel S960QL.

The article discusses the effect of the hybrid-welding process (laser–electric arc MAG Metal Active Gas) on the structure and properties of butt joints (having various thicknesses, i.e., 5 mm and 7 mm) made of steel S960QL. Welding tests were performed in the flat position (PA) and in the horizontal position (PC). Joints made of steel S960QL in the above-presented configuration are present in elements of crane structures (e.g., telescopic crane jibs). The welding tests involved the use of the G Mn4Ni1.5CrMo solid electrode wire and the Ar+18% CO2 shielding gas mixture (M21) (used in the MAG method). Non-destructive visual and radiographic tests did not reveal the presence of any welding imperfections in the joints. The welded joints obtained in the tests represented quality level B in accordance with the requirements of the ISO 12932 standard. Microscopic metallographic tests revealed that the heat-affected zone (HAZ) contained the coarse-grained martensitic structure resulting from the effect of the complex welding thermal cycle on the microstructure of the joints. Destructive tests revealed that the joints were characterised by tensile strength similar to that of the base material. The hybrid welding (laser–MAG) of steel S960QL enabled the obtainment of joints characterised by favourable plastic properties and impact energy exceeding 27 J. The tests revealed the possibility of making hybrid-welded joints satisfying the quality-related requirements specified in the ISO 15614-14 standard.

Stress-strain state during recovery objects with corrosion defects by welding

The urgency of the problems connected with periodical diagnostics and repair of the linear section of main pipelines and the expediency of the use of repair technologies for restoration of the required wall thickness are proved. The experimental part of the work was the welding of a corrosion defect on the outer surface of the pipe by successive surfacing of the “filament” rollers in the environment of CO2 (MAG) – metal active gas and manual arc (MMA) – manual metal arc method in three layers, with a contour seam. The results of the residual stress-strain state obtained experimentally by brewing the defect of corrosive origin are presented, as well as the modeling of the stress-strain state (NDS) by the finite element method (ITU), which is formed at the same time on the section of a tube of 17G1C steel with a diameter of 1420 × 16 mm. As a defect model, a hollow oval shape with dimensions of 100 × 60 mm and a depth of 6 mm in the central part was made. The analysis and comparison of stress distribution, plastic deformations and displacements for these methods were made. The main factors influencing the VAT are established. It is shown that the VAT for different welding methods has the same distribution pattern, but differs in size. An assumption is made about the interconnection of displacements of the sample in the formation of residual stresses in the free state and, in the presence of rigid ligaments. The appropriateness of using the MAG method of repairing the thinned section of the main pipeline in terms of the formation of residual VAT rates has been confirmed. The effect is related to the formation of an area with increased values of residual tensile stress after the overlap of the last seam of each layer due to the effect of transverse and longitudinal shrinkage of the metal through the interaction of the last roller in the layer with the side wall of the defect.

Hybrid Surfacing: Laser + MAG Electric Arc

The article discusses technological tests involving the use of the hybrid process (laser + electric arc (MAG)) for the efficient application of layers (surfacing). The objective of the tests was to determine the effect of an additional welding power source (laser beam) on the possibility of increasing a surfacing rate (in comparison with surfacing rates obtainable using the MAG method) as well as on the formation (shaping) of the overlay weld geometry and the degree of dilution (of the base material in the overly weld). The technological tests of the hybrid (HLAW (laser + MAG)) surfacing process involved the use of steel grade 41Cr4 and filler metal grade LNM 307.

Direction of the Rolling of Plates Made of Steel Grade 0H18N9 versus Welding Distortions

The article presents the results of tests concerning the effect of the direction of the rolling of plates made in steel 0H18N9 on welding distortions. The research-related analysis was concerned with the rolling direction in relation to the longer edge of specimens. The specimens were welded using the MAG method involving the use of pulsed arc. The acquisition of surface flatness-related data was performed using a GOM ATOS 5M blue light scanner. The analysis of the results revealed that the mean surface flatness of the specimens was similar in relation to all of the rolling directions related to analysis. However, the direction of distortions parallel and perpendicular to the weld varied depending on the direction of rolling.

Innovative Robotic System for MAG Welding with Two Filler Metal Wire Feeders

The article describes an innovative robotic MAG method for the welding for ship elements. The method involves the use of two wire feeders and one torch, making it possible to weld two different steel grades. In addition, the robot application is equipped with an off-line programming DTPS system (Desk Top Programming & Simulation System) as well as an arc sensor, a gas nozzle touch sensor and a laser touch sensor featuring a seam finding function. The system is also provided with a welding parameter monitoring and archiving system.

Mechanical Properties of Joints Made in Steel S1300QL Using Various Welding Methods

The article presents applications of high-strength quenched steels in various industrial sectors and the chronological development of various grades of the aforesaid steels. The research-related tests involved flat butt joints made in 7 mm thick steel grade S1300QL, welded using the following methods: TIG, A-TIG, MAG involving the use of a hard flux-cored surfacing wire, MAG method involving the use of a solid wire, T.I.M.E. method involving the use of a solid wire, laser welding method without the use of the filler metal, hybrid (HLAW) method involving the use of a metallic flux-cored wire, electron beam welding without using the filler metal. The research also involved the performance of the mechanical properties of the welded joints made in quenched steel S1300QL using various welding methods. The joints made using the laser welding method, hybrid welding method and the electron beam welding method were characterised by tensile strength higher than the minimum yield point of steel S1300QL, amounting to 1300 MPa. In turn, the tensile strength of the joints made in steel S1300QL using arc welding methods was lower than the minimum yield point of the steel. All of the test joints were subjected to non-destructive digital radiographic tests. The tests concerning the mechanical properties of the joints with respect to various welding methods were subjected to comparative analysis. The research work finished with the formulation of concluding remarks concerning the mechanical properties of the joints.

Analysis of the structure and selected properties of welds obtained by the CMT and MAG method

The article presents an analysis of the Cold Metal Transfer (CMT) method, including the process, advantages and application of the method. The joints made with low energy CMT method and classic MAG method were also compared. The paper presents the results of non-destructive penetrant tests of welded joints made of steel in the S235JR grade. Microscopic observations were made using optical microscopy and the hardness was measured in accordance with PN-EN ISO 6507-1:2007. The test results confirmed that the CMT process allows for the production of high-quality joints and a narrow heat-affected zone compared to the classic MAG welding method, and also provides good mechanical properties and elimination of spatter.

Assessment of the quality of abrasion-resistant plates welded joint

The article presents the analysis of the structure and properties of joints made of abrasion-resistant plates having the structure of chromium cast iron and welded with filler metals, the use of which aimed to provide the high abrasion resistance of the surface layer and good mechanical properties of the base material. The face layer of the joint was made using the MMA (Manual Metal Arc) welding method and the Fe-Cr-Nb-B type nanocrystalline filler metal. The root weld was welded using an austenitic filler metal, whereas the filling layer was welded using the MAG method with a low-alloy filler metal. The joints were subjected to non-destructive tests (visual tests and penetrant tests) as well as to mechanical properties tests. The research involved macro and microscopic metallographic tests, the determination of the grain size using an Xpert PRO X-ray diffractometer, and the EDS analysis of the chemical composition of the precipitates. The assessment of the operational properties of the joints based on hardness measurements, static tensile tests, bend tests as well as identifying the metal-mineral abrasive wear resistance were performed in accordance with ASTM G65 ? 04 standards. The results of the abrasion resistance tests were referred to the HARDOX 400 steel reference specimen. Considering the tests results it was concluded that the used filler materials can assure the appropriate operational properties of welded abrasion-resistant plates.

Properties of weld overlays on regenerated wheel hub of a mining vehicle

The paper presents problems related to the regeneration of wheel hubs for mining machinery vehicles carried out with arc welding using the MAG method. Hubs made of medium-carbon cast steel, type LII500, were weld surfaced with filler metal grade of G4Si. The tests were aimed at determining welding imperfections and metallographic properties of the surfacing welds. The influence of heat treatment on the properties of surfacing was investigated. Hardness distributions in welded hubs after various heat treatment operations were determined. Recommendations for the technology of weld surfacing the wheel hubs were formulated.

The influence of the cooling method on shortening the cycle of multi-layer arc-surfacing of thin walls

The use of 3D printing methods in the industry is becoming more frequent and popular. It brings specific economic effects, enables quick and precise production of machine parts and devices. The article presents a fragment of research carried out in the Welding Engineering Department of the Warsaw University of Technology on the application of MAG arc welding for 3D printing. The MAG method was used to try to produce thin walls. The aim of the presented research was to determine the effect of the cooling method on shortening the time of manufacturing the 3D model of thin walls. The models were made using G3Si1 and 316LSi electrode wires. In the first part of the research,an interpass temperature of 50 °C, 100 °C and 150 °C, achieved by free cooling was adopted. In the second part, the interpass temperature was 100 °C and was achieved by forced cooling with a copper plate, a fan and a stream of compressed air. The greatest reduction in the time of manufacturing the 3D model of a thin wall was obtained for cooling using compressed air.

An Analysis of the Quality of the Thick-Walled S355J2+N Steel Joint Welded by the Mag Method

AbstractAn analysis of the quality of the thick-walled S355J2+N steel welded joint used most frequently in the general-building, power and other contemporary steel constructions is presented in the following article. A process of examining welding technologies was made on the tick-walled butt joints of plates by using the MAG – 135 welding method. The aim of the discussed topic was to optimize the process of welding thick-walled welded joints due to their mechanical strength properties and efficiency.

Fuzzy Risk Analysis Based on Ranking of Fuzzy Numbers Via New Magnitude Method

Ranking fuzzy numbers plays a main role in many applied models in real world and in particular decision-making procedures. In many proposed methods by other researchers may exist some shortcoming. The most com- monly used approaches for ranking fuzzy numbers is based on defuzzication method. Many ranking fuzzy numbers cannot discriminate between two sym- metric fuzzy numbers with identical core. In 2009, Abbasbandy and Hajjari proposed an approach for ranking normal trapezoidal fuzzy numbers, which computed the magnitude of fuzzy numbers namely \Mag method. Then Ha- jjari extended it for non-normal trapezoidal fuzzy numbers and also for all generalized fuzzy numbers. However, these methods have the weakness that we mentioned above. Moreover, the result is not consistent with human intu- ition in this case. Therefore, we are going to present a new method to overcome the mentioned weakness. In order to overcome the shortcoming, a new magni- tude approach for ranking trapezoidal fuzzy numbers based on minimum and maximum points and the value of fuzzy numbers is given. The new method is illustrated by some numerical examples and in particular, the results of ranking by the proposed method and some common and existing methods for ranking fuzzy numbers is compared to verify the advantages of presented method.

Productivity assessment of the low-energy SpeedRoot welding process in PG position

The article presents the results of experimental studies aimed at comparing the welding conditions and technological properties of butt joint welding in the PG position using the innovative low-energy variant of the MAG method – SpeedRoot, with conventional TIG welding in the PF position. The productivity of both welding processes has been evaluated, as well as the dynamic characteristics of power sources and the macrostructure of obtained joints.

THE INFLUENCE OF WELDING ON THE HARDNESS AND WELDABILITY OF THERMALLY HARDENED S620Q STEEL SHEETS

The thermally hardened 12 mm sheets of S620Q steel underwent research. The sheets weldability was examined during semi-automatic welding by MAG method, at the welding conditions usually applied in industry for welding normalized sheets of this steel. The technology of welding was presented. The achievement of metallically continuous joints was confirmed by X-ray examination. For the purpose of usefulness assessment, samples were taken from test joints then the joints hardness distribution measurements were performed. The microstructure was examined and the static tensile tests as well as technological bend tests were carried out. Hardness measurements were performed in three measurement lines for each joint according to PN-EN 1043-1:2000 requirements. Joints microstructures were examined in the joints axis, in SWC and in native materials. Steel microstructures were classified as low carbon tempered martensite of layered construction. Mean values of the selected joints strengths were also presented. The tensile tests values of native materials of metallurgic certificates were given for the sake of comparison. The research results presented in the paper made it possible to determine the weldability of S620Q steel.

THE WELDABILITY ASSESSMENT OF THERMALLY HARDENED S540Q STEEL SHEETS

High strength thermally hardened steels are more difficult to weld than low carbon construction steels. There is a danger of cold cracking caused by the presence of martensite in welded joints. The thermally hardened 12 mm sheets of S540Q steel underwent research. The sheets were welded semi-automatically by MAG method, in the welding conditions usually applied in industry for welding normalized sheets of this steel. The welding technology was presented. The X-ray tests were performer, which confirmed the achievement of metallically continuous joints. Samples were taken from the joints and the joints hardness distribution measurements were conducted. The microstructure was examined and the static tensile tests as well as technological bend tests were carried out. Hardness measurements were performed in three measurement lines for each joint according to PN-EN 1043-1:2000 requirements. Joints microstructures were examined in the joints axis, in HAZ and in native materials. Steel microstructures were classified as low carbon tempered matrensite of layered construction. Mean values of the selected joints tensile strengths were also presented. The tensile tests values of native materials of metallurgic certificates were given for the sake of comparison. The research results presented in the paper made it possible to determine the weldability of S540Q steel.

Protection of welded joints against corrosion degradation

Welded joints form an integral part of steel constructions. Welded joints are undetachable joints, which are however subjects of corrosion processes. The internal energy increases during the fusion welding especially in the heat affected places around the welded joint, which become initiating spot of corrosion degradation.The aim of the experiment is to put a welded joint produced by the MAG method to a test of corrosion degradation under the conditions of the norm ČSN ISO 9227 (salt-spray test). Organic and inorganic anticorrosion protections were applied on welded beads. First of all, there were prepared welded beads using the method MAG; secondly, metallographical analyses of welded metal, heat affected places and base material were processed. Further, microhardness as well as analysis of chemical composition using the EDS microscope were analysed. Based on a current trend in anticorrosion protections, there were chosen three types of protective coatings. First protective system was a double-layer synthetic system, where the base layer is formed by paint Pragroprimer S2000 and the upper layer by finishing paint Industrol S 2013. Second protective system is a duplex system formed by a combination of a base zinc coating with Zinorex paint. The last protective system was formed by zinc dipping only. Corrosion resistance of the individual tested samples was evaluated based on degradation of protective coating. The corrosion origin as well as the corrosion process were observed, the main criteria was the observation of welded bead.

Duplex steel welding in the construction of railway vehicles

The range of application of stainless steel in the railway industry is discussed. The results of testing of butt welded joints made in dissimilar materials are presented: 1.4462 and S500MC steel. The joints were made in two variants, namely with the use of solid wire and with the use of flux-cored wire. The test results show that the properties of joints made by the MAG method with the use of flux-cored wire are similar to those made with solid wire.