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An experimental investigation for developing structure-property correlations of hot-rolled E410 steels with different carbon contents, i.e. 0.04wt.%C and 0.17wt.%C metal active gas (MAG) and cold metal transfer (CMT)-MAG weldments was undertaken.

Mechanical properties and microstructure of MAG and CMT-MAG weldments of two E410 steels with varying content of carbon were compared using standardized mechanical testing procedures, and conventional microscopy.

0.04wt.%C steel had strained ferritic and cementite sub-structures in blocky shape and large dislocation density, while 0.17wt.%C steel consisted of pearlite and polygonal ductile ferrite. This effected yield strength (YS), and microhardness being larger in 0.04wt.%C steel, %elongation being larger in 0.17wt.%C steel. Weldments of both E410 steels obtained with CMT-MAG performed better than MAG in terms of YS, ultimate tensile strength (UTS), %elongation, and toughness. It was due to low heat input of CMT-MAG that resulted in refinement of weld metal, and subzones of heat affected zone (HAZ).

A substantial improvement in YS (∼9%), %elongation (∼38%), and room temperature impact toughness (∼29%) of 0.04wt.%C E410 steel is achieved with CMT-MAG over MAG welding. Almost ∼10, ∼12.5, and ∼16% increment in YS, %elongation, and toughness of 0.17wt.%C E410 steel is observed with CMT-MAG. Relatively low heat input of CMT-MAG leads to development of fine Widmanstätten and acicular ferrite in weld metal and microstructural refinement in HAZ subzones with nearly similar characteristics of base metal.

The purpose of this paper is to provide a modified welding image feature extraction algorithm for rotating arc narrow gap metal active-gas welding (MAG) welding, which is significant for improving the accuracy and reliability of the welding process.

An infrared charge-coupled device (CCD) camera was utilized to obtain the welding image by passive vision. The left/right arc position was used as a triggering signal to capture the image when the arc is approaching left/right sidewall. Comparing with the conventional method, the authors’ sidewall detection method reduces the interference from arc; the median filter removes the welding spatter; and the size of the arc area was verified to reduce the reflection from welding pool. In addition, the frame loss was also considered in the authors’ method.

The modified welding image feature extraction method improves the accuracy and reliability of sidewall edge and arc position detection.

The algorithm can be applied to welding seam tracking and penetration control in rotating or swing arc narrow gap welding.

The modified welding image feature extraction method is robust to typical interference and, thus, can improve the accuracy and reliability of the detection of sidewall edge and arc position.

Evaluates the applicability of ultrasonic sensors in a welding environment and reports on experimental measurements carried out with a sensory head containing ultrasonic transducers with different frequencies. Analyses the effects on the sensors of factors such as noise, temperature and shielding gas flow and concludes by suggesting appropriate protective measures for the sensors for them to operate effectively in a welding environment.

Associating robot manipulators with industrial welding operations is common and maybe one of the most successful applications of industrial robots. Nevertheless, it is far from being a solved technological process, mainly because the welding process is not fully understood but also because robots are still at an early satge of development, being difficult to use and program by regular operators. This is also true for Human Machine Interfaces (HMI), which are not intuitive to use and are therefore unsatisfactory. In this paper we discuss these problems and present a system designed with the double objective of serving our R&D efforts on welding applications, but also our need to assist industrial partners working with welding setups. Frequently industrial partners are not happy with available commercial systems, requiring tailored solutions that could be adapted to several robots and robot controllers. The developed system is explained in some detail, and demonstrated using two test cases which reproduce two situations very common in industry: multi‐layer butt welding (used on big structures requiring very strong welds) and multi‐point fillet welding (used for example on structural pieces for the construction industry).

This paper aims to develop a method to extract the weld seam from the welding image.

The initial step is to set the window for the region of the weld seam. Filter and edge‐operator are then applied to acquire edges of images. Based on the prior knowledge about characteristics of the weld seam, a series of routines is proposed to recognize the seam edges and calculate the seam representation.

The proposed method can be used to extract seams of different deviations from noise‐polluted images efficiently. Besides, the method is low time‐consuming and quick enough for real time processing.

Weld seam extraction is the key problem in passive vision based seam tracking technology. The proposed method can extract the weld seam even when the image is noisy, and it is quick enough to be applied in seam tracking technology. The method is expected to improve seam tracking results.

A useful method is developed for weld seam extraction from the noise‐polluted image based on prior knowledge of weld seam. The method is robust and quick enough for real time processing.

Reviews the Essen Schweissen und Schneiden cutting and welding trade show, identifies mounting trend for electric servo guns to replace pneumatic welding guns, reports on growing interest in aluminium welding and outlines the different solutions proposed, assesses the latest developments in remote laser welding technology.

This paper presents the architecture of a system for robotic welding of complex tasks. The system integrates off‐line programming, control of redundant robots, collision‐free motion planning and sensor‐based control. An implementation for pipe structure welding made at Odense Steel Shipyard Ltd., Denmark, demonstrates the system can be used for automatic welding of complex products in one‐of‐a‐kind production.

To provide information about technical data; wear behaviour of worn rotor parts in mining industry and for the other application of ferrous alloys.

Wear behaviour of the various filler wires were tested (tensile, hardness, and wear) and compared with each other in the light of microstructure, chemical, and mechanical properties.

The results showed that the wear rates were significantly increased with the increasing load, welding current, wear distance and poor mechanical properties. A larger amount of C, Cr, and Mn specimen showed the best wear resistance since it contained a number of hard MC‐type carbides and coarse grains. Furthermore, for all materials the weight loss increases linearly with the increasing of welding arc current, load and wear distance.

It would be interesting to search about the toughness values and fatigue behaviour of these materials. It could be the good idea for future work could be concentrated fracture surface analysis of these materials.

For these materials choosing the right chemical composition of the filler material, certain arc current and ideal microstructure is crutial for the wear response.

The main value of this paper is to contribute and fulfil the mechanical properties of welding wires that is being studied so far in the literature such as the effects of chemical composition, applied road range, and arc current on the tensile, hardness and wear behaviours of the welding wires.

Joining, while first and foremost a pragmatic undertaking, concerned more with needs and results than with theory, will likely have to change with the dawn of the twenty‐first century to a true science. As materials become ever‐more sophisticated in their chemical composition, molecular morphology, micro‐ and nano‐structure, and macro‐structural arrangement 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 joining will surely evolve – sometimes to provide unimagined capabilities. But, 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. This paper takes a glance at the past and a hard look at the present in the hope of catching a glimpse of the future.

Describes the materials and methods used in the building of two multipurpose icebreaker vessels by a Finnish shipyard. Details the different welding processes used for each vessel and the welding consumables chosen for each of the vessels' hulls.