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The great fluidity of titanium metal in the molten condition lends itself to fusion welding without the addition of filler metal. The resulting welds are flush with the base metal and have high ductility, comparable to the ductility of the base metal. The welded joints can be made by hand or automatic methods. A critical requirement of this type of weld is fit‐up of the parts to be joined. The back‐up and hold‐down fixtures also have a decided effect on the resulting weld. A sheared surface resulting in a joint without gaps is required for a satisfactory weld. Fused welds have been principally used, to date, for longitudinal tight butt joints in material up to .062 in. thick. Further testing and experience should extend the limits of application. Bend tests made on welded samples have bent 180 deg. over a 2T bend radius exhibiting equal or greater ductility than the base metal. Welds tested in tension have exhibited over 100 per cent efficiency in all cases. The elimination of welding rod has reduced the amount of contamination in the weld and the weld area.

The purpose of this paper is to investigate interface characterization of CO₂ laser welded AISI 304 austenitic stainless steel and AISI 1010 low carbon steel couple. Laser welding experiments were carried under argon and helium atmospheres at 2000, 2250 and 2500 W heat inputs and 200‐300 cm/min welding speeds.

The microstructures of the welded joints and the heat affected zones (HAZ) were examined by optical microscopy, SEM, EDS and X‐Ray analysis. The tensile strength of the welded joints was measured.

The result of this study indicated that the width of welding zone and HAZ became much thinner depending on the increased welding speed. On the other hand, this width widened depending on the increased heat input. Tensile strength values also confirmed this result. The best properties were observed at the specimens welded under helium atmosphere, at 2500 W heat input and at 200 cm/min welding speed.

There are many reports which deal with the shape and solidification structure of the fusion zone of laser beam welds in relation to different laser parameters. However, the effect of all influencing factors of laser welding has up to now not been extensively researched. Much work is required for understanding the combined effect of laser parameters on the shape and microstructure of the fusion zone. This paper, therefore, is concerned with laser power, welding speed, defocusing distance and type of shielding gas and their effects on the fusion zone shape and final solidification structure of some stainless steels.

The essence of a successful weld is that the joint should possess similar properties to the parent material. In the welding of stainless materials it is essential that the corrosion resistance be preserved in the weld metal and adjacent areas. In this article the author discusses the difficulties involved and the means whereby corrosion resistance is maintained.

Military and unmanned aerial vehicles (UAV) applications like rocket motor casings, missile covers and ship hulls use components that are made of maraging steel. Maraging steel has properties that are superior to other metals, making it more suitable for the fabrication of such components. A grey relational analysis (GRA) that is based on the Taguchi method has been utilised in the current study to optimise a laser beam welding (LBW) process. Further aspects such as GRA's optimum ranges and percentage contributions were also estimated.

A Taguchi L16 orthogonal array is utilised to design and conduct the experiments. Laser power (LP), welding speed (WS) and focal position (FP) are the three parameters are chosen for the process of welding. The output responses are the upper width of the heat-affected zone (HAZup), the upper width of the fusion zone (FZup) and the depth of penetration (DOP). The effect of the above key parameters on the responses was examined using an analysis of variance (ANOVA).

The results of ANOVA reveal that the parameter that has the most influence on the overall grey relational grade (GRG) is the FP. Finally, metallographic characterisation and a microstructural analysis are conducted on the weld bead geometry to demarcate the zone of HAZ and fusion zone (FZ).

As the most important criteria for LBW of maraging steels is the provision of higher DOP, higher FZ width and lower heat-affected zone, the study intended to prove the applicability of GRA technique in solving multi-objective optimisation problems in applications like defence and unmanned systems.

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.

The purpose of this paper is to present the results of a metallurgical, mechanical and tribological characterization of the weld and heat-affected zone (HAZ) of aluminothermic welding of premium rails used in heavy haul, looking into the origins of the squat defects associated with rail wear.

A full factorial design of experiment was carried out for 24 welds of premium and super premium rails. The factors studied were chemical composition, welding gap and preheating time. The welds were inspected visually and by ultrasound to detect superficial and internal defects and characterized by macrographic analysis, hardness profile, tensile tests and microstructural characterization in scanning electronic microscopy. Pin-on-disk test were carried out to compare the tribological behavior of the different regions of the weld rail.

Squat formation was shown to be associated with spheroidized pearlite regions formed on the HAZ of the welds, presenting near half the hardness of the weld metal. Thermal analysis showed that spheroidized pearlite is a result of partial austenitization at these positions. Tribological tests showed that low hardness regions presented smaller wear resistance than both the weld metal and the parent rail. Tensile test of the whole region resulted in brittle fracture along the weld metal.

The results showed that it is essential to reduce the dimensions of the HAZ and the width of the hardness drop area to mitigate squat formation in the HAZ edges.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0020/

The purpose of this paper is to evaluate the welding quality of the friction stir joints of Al-SiC with diverse shape of pin geometry tools.

Aluminum matrix composites are gaining unlimited interest and special position in aeronautical industry because of their properties enhanced by the presence of ceramic reinforcement, such as lower density, dimensional stability, exceptional wear and abrasion resistance. Friction stir welding arises as a promising welding process with more advantages than traditional fusion process in the joining of aeronautical components with the utilization of a non-consumable rotational tool shaped by a shoulder and a pin, which can be designed in as many possible geometries. However, the welding quality is not always achieved when varying these pin configurations.

The fabrication and implementation of different pin geometry tools to weld the plates of the material allows to study the behavior of the joints assessing some discontinuities produced in the welds.

To examine the microstructural evolution and its behavior in the different zones of the joint, the practical implication consists in the use of different characterization techniques like the optic microscopy and scanning microscopy, furthermore mechanical test such as the measurement of hardness.

The study of the joints uses different welding tool geometries that were fabricated at prototype scale contribute in the microstructural analysis as well as in the evaluation of the possible discontinuities that are presented.

THE need for the conservation of materials has stimulated interest in the various methods of salvaging components which have become worn in service or inadvertently machined under‐size. The practical methods now employed include electro‐deposition, “fescolizing”, bronze welding and metal spraying. There remains a good deal to be learnt on the subject from the technical point of view, and it can safely be said to have touched only the fringe of the vast wastage of scrap components which could be recovered, with considerable saving in material, labour and money.

The purpose of this paper is to present and implement an algorithm to prioritize welding quality deterioration factors for improving welding personnel performance. A case study is carried out in a piping components fabrication process which supplies these components to oil and gas production and processing facilities on the Norwegian continental shelf (NCS).

The quality deterioration factors' prioritization is carried out using statistical methods in conjunction with the data recorded in the welding inspection database (WIDB) of the case study company. Data cleaning and rearrangements were performed to reflect final objective. Based on the welding procedure specifications (WPSs) and quality imperfection groups classified in NS‐EN ISO 6520‐1, the analysis is performed to prioritize the welding quality deterioration factors.

Based on the WPSs and quality imperfection groups classified in NS‐EN ISO 6520‐1, it is possible to prioritize the welding quality deterioration factors. These factors are possible to use for improving the performance of welding personnel to assure the quality of welds in steel fabrications.

The factors prioritized are possible to use for improving the performance of welding personnel to assure the quality and reliability of welds in a steel fabrication.

Assuring quality as proposed in the manuscript, the catastrophic failures that are potential in production and process plants can be mitigated. This enhances health, safety and environmental performance of welds in steel fabrications.

The value of this paper is to illustrate an innovative approach to a real life quality problem; it demonstrates how the application of qualitative and quantitative quality instruments in accordance with technical specification can help in increasing and maintaining product compliance and in optimizing the management of resources.