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Welding Metallurgy of

01 Jan 1987-
About: The article was published on 1987-01-01 and is currently open access. It has received 991 citations till now. The article focuses on the topics: Welding.
Citations
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Journal ArticleDOI
TL;DR: In this article, the influence of processing on the microstructure and hardness of coatings of alloy Colmonoy-6® was assessed in both cases, the alloy was processed by plasma transferred arc and high-power diode laser on plates of AISI 304 with two levels of dilution.
Abstract: The processing technique is decisive for the characteristics of a coating. This is because the heat supply, which depends on the technique and on the parameters, has an influence on the dilution and the solidification rate. In alloys with low metallurgical complexity, the effect of processing with deposition techniques that give a higher cooling rate may be translated into refining of the microstructure. A more refined microstructure is expected to result in higher mechanical strength of the coating. However, in the deposition of alloys that are more complex metallurgically this does not always occur, because the high cooling rate may suppress formation/precipitation of phases responsible for strength. The influence of processing on the microstructure and hardness of coatings of alloy Colmonoy-6® was assessed in this study. The alloy was processed by plasma transferred arc and high-power diode laser on plates of AISI 304 with two levels of dilution. In both cases, good-quality, defect-free coating...

16 citations

Journal ArticleDOI
TL;DR: In this article, an automatic tungsten-inert gas welding (ATIGW) of AZ31 Mg alloys was performed using a six-axis robot, and the evolution of the microstructure and texture of the AZ31 auto-welded joints was studied by optical microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy, and electron backscatter diffraction.
Abstract: The automatic tungsten-inert gas welding (ATIGW) of AZ31 Mg alloys was performed using a six-axis robot. The evolution of the microstructure and texture of the AZ31 auto-welded joints was studied by optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electron backscatter diffraction. The ATIGW process resulted in coarse recrystallized grains in the heat affected zone (HAZ) and epitaxial growth of columnar grains in the fusion zone (FZ). Substantial changes of texture between the base material (BM) and the FZ were detected. The {0002} basal plane in the BM was largely parallel to the sheet rolling plane, whereas the c-axis of the crystal lattice in the FZ inclined approximately 25° with respect to the welding direction. The maximum pole density increased from 9.45 in the BM to 12.9 in the FZ. The microhardness distribution, tensile properties, and fracture features of the AZ31 auto-welded joints were also investigated.

16 citations


Cites background from "Welding Metallurgy of"

  • ...direction in hexagonal close-packed (HCP) materials, including Mg [16]....

    [...]

Journal ArticleDOI
TL;DR: In this paper, it was shown that liquid gold at 1000 degrees C penetrates the immersed stainless steel C-ring at grain boundaries, but only when tensile stresses are applied.

16 citations

Journal ArticleDOI
Abstract: In recent years, the usage of dual phase (DP) steels, transformation induced plasticity (TRIP) steels and boron steels in some auto body parts has become a necessity because of their strength and lightweight. Resistance spot welding (RSW) being a process were steel is heated and cooled in a very short period of time, the resulting weld nugget is generally fully martensitic, especially in the case of DP, TRIP and boron steels but that also holds for plain carbon steels as AISI 1010 grade which is extensively used in auto body inner parts. Martensite in is turn must be avoided as much as possible when welding steel because it is the principal source of brittleness. Thus, this work aims in finding a mean to reduce martensite fraction and increase phase diversity in weld nugget. The prediction of phase transformation during RSW has been done. Simulations have been performed for 2 mm AISI 1010 sheets and results show that the application of post weld heat treatment leads to the reduction of martensite fraction, and formation of ferrite and bainite in the nugget. Welding experiments have been done in parallel and experimental weld nugget geometry is in good agreement with simulation results.

16 citations

Journal ArticleDOI
Nohoon Kim1, Woong Gil, Heui-dae Lim, Chang-hyeon Choi, Hae Woo Lee1 
TL;DR: In this article, the effect of the Mo content on the mechanical and corrosion properties of hyper duplex stainless-steel welds that are subjected to flux cored arc welding (FCAW) was investigated.
Abstract: This study investigates the effect of the Mo content on the mechanical and corrosion properties of hyper duplex stainless-steel welds that are subjected to flux cored arc welding (FCAW). Conventional hyper duplex stainless steel has limited productivity owing to the welding position and welding equipment of gas tungsten arc welding (GTAW) and submerged arc welding (SAW). As such, the purpose of this study is to develop a weld material for FCAW, which is not subject to the limitations of GTAW and SAW, as well as to improve productivity and quality. FCAW was performed under the same conditions, except for the Mo content, which were varied to 3, 4.5, and 6 wt%. Tensile and impact tests were carried out to investigate the variation of the mechanical properties according to the Mo content. As the Mo content increased, the elongation decreased and the strength increased. It was confirmed that the δ-ferrite phase increased and the γ-austenite phase decreased as the Mo content increased. Secondary phase such as σ phase, χ phase were mainly distributed in ferrite grains or austenite–ferrite grain boundaries using EBSD. It was also increased as the Mo content increased. To evaluate the corrosion resistance, Potentiodynamic Polarization Tests and DL-EPR tests were conducted. As a result, all of specimens showed similar corrosion resistance.

16 citations

References
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Journal ArticleDOI
TL;DR: In this article, the state of the art in selective laser sintering/melting (SLS/SLM) processing of aluminium powders is reviewed from different perspectives, including powder metallurgy (P/M), pulsed electric current (PECS), and laser welding of aluminium alloys.

1,172 citations

Journal ArticleDOI
TL;DR: In this article, the authors show that the pre-existing dislocation network, which maintains its configuration during the entire plastic deformation, is an ideal modulator that is able to slow down but not entirely block the dislocation motion.

557 citations

Journal ArticleDOI
TL;DR: In this article, the fundamental understanding of structure-properties relationship in automotive steels resistance spot welds is discussed. And a brief review of friction stir spot welding, as an alternative to RSW, is also included.
Abstract: Spot welding, particularly resistance spot welding (RSW), is a critical joining process in automotive industry. The development of advanced high strength steels for applications in automotive industry is accompanied with a challenge to better understand the physical and mechanical metallurgy of these materials during RSW. The present paper critically reviews the fundamental understanding of structure–properties relationship in automotive steels resistance spot welds. The focus is on the metallurgical characteristics, hardness–microstructure correlation, interfacial to pullout failure mode transition and mechanical performance of steel resistance spot welds under quasi-static, fatigue and impact loading conditions. A brief review of friction stir spot welding, as an alternative to RSW, is also included.

369 citations

Journal ArticleDOI
TL;DR: In this article, a unified equation to compute the energy density is proposed to compare works performed with distinct equipment and experimental conditions, covering the major process parameters: power, travel speed, heat source dimension, hatch distance, deposited layer thickness and material grain size.

369 citations

Journal ArticleDOI
TL;DR: This study attempted to predict solidification defects by DNN regression with a small dataset that contains 487 data points and found that a pre-trained and fine-tuned DNN shows better generalization performance over shallow neural network, support vector machine, and DNN trained by conventional methods.

314 citations