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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
24 Feb 2021
TL;DR: The bimetallic welds are frequently utilized for pipeline transport system of the nuclear power plants of the United States and the occurrences of welding defects generally depend on the filler electrode as well as the el...
Abstract: The bimetallic welds are frequently utilized for pipeline transport system of the nuclear power plants. The occurrences of welding defects generally depend on the filler electrode as well as the el...

2 citations


Cites background from "Welding Metallurgy of"

  • ...SiO2 gets dissociated into silicon and oxygen during slag-metal reactions and thereby raises the silicon content in the weld.(43) Al2O3 tends to decrease Table 4....

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Journal ArticleDOI
TL;DR: In this paper, the microstructure and mechanical properties of 2205 duplex stainless steel/A517 quench and tempered low alloy steel dissimilar joint were investigated by optical microscopy, scanning electron microscopy equipped with an energy dispersive spectroscopy and X-ray diffraction.
Abstract: In the present research, microstructure and mechanical properties of 2205 duplex stainless steel/A517 quench and tempered low alloy steel dissimilar joint were investigated. For this purpose, gas tungsten arc welding was used with ER2209 filler metal. Characterizations were conducted by optical microscopy, scanning electron microscopy equipped with an energy dispersive spectroscopy and X-ray diffraction. Mechanical properties were evaluated in micro-hardness, tensile and impact tests. Microstructure in the weld zone included an austenitic continuous network in the matrix of primary ferrite. No brittle phases were formed in the weld metal and stainless steel heat affected zone (HAZ). The weld metal/A517 interface showed higher hardness than other regions. Tensile tests indicated that the values of the yield and tensile strength were 663 and 796 MPa, respectively. Impact tests indicated that the weld zone had almost the same impact energy as base metals. The minimum impact energy of 12 J was related to A517 HAZ. The results of scanning electron microscopy for fracture surfaces indicated that weld zone, 2205 HAZ and A517 HAZ had ductile, ductile–brittle and brittle fracture mode, respectively.

2 citations


Cites background from "Welding Metallurgy of"

  • ...Because of high temperature of the welding, the steel structure of the base state (tempered martensite) is changed; and after cooling, due to lack of sufficient time for auto-tempering, the structure changes into not tempered martensite during rapid cooling [17]....

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Journal ArticleDOI
TL;DR: In this paper, the microstructures and toughness of simulated coarse grain heat-affected zone of hot continuously rolled copper-bearing steel were investigated using physical simulation, and the results showed that brittlement is easy to happen in the region of CGHAZ with slower thermal cycles (t8/5/45s) Granular bainite transformed from austenite led to brittlement.
Abstract: Microstructures and toughness of simulated coarse grain heat-affected zone of hot continuously rolled copper-bearing steel were investigated using physical simulation The results showed that brittlement is easy to happen in the region of CGHAZ with slower thermal cycles (t8/5≥45s) Granular bainite transformed from austenite led to brittlement The dimensions of granular martensite and austenite (M-A) constituents are main factors influencing the impact toughness There is no visible effect on the toughness when the dimensions of M-A constituents are less than 1μ m However, the toughness decreases greatly once the dimensions exceed 1μ m Therefore, decreasing the dimensions of M-A constituents by controlling weld heat input will do good to improve the impact toughness of copper-bearing steel

2 citations


Cites background from "Welding Metallurgy of"

  • ...In general, coarse grain heat-affected zone (CGHAZ) of welding joint is the region that has the greatest potential for weldability problems [6]....

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Journal ArticleDOI
TL;DR: In this article, a study has been done to explore the effects of parameters of laser welding process, namely, welding speed, laser lamping current, and pulse duration, on the coercivity of laser welded AISI 430 stainless steel.
Abstract: The AISI 430 stainless steel with ferritic structure is a low cost material for replacing austenitic stainless steel because of its higher yield strength, higher ductility and also better polarisation resistance in harsh environments. The applications of AISI 430 stainless steel are limited due to insignificant ductility and some undesirable changes of magnetic properties of its weld area with different microstructures. In this research, a study has been done to explore the effects of parameters of laser welding process, namely, welding speed, laser lamping current, and pulse duration, on the coercivity of laser welded AISI 430 stainless steel. Vibrating sample magnetometery has been used used to measure the values of magnetic properties. Observation of microstructural changes and also texture analysis were implemented in order to elucidate the change mechanism of magnetic properties in the welded sections. The results indicated that the laser welded samples undergo a considerable change in magnetic properties. These changes were attributed to the significant grain growth which these grains are ideally oriented in the easiest direction of magnetization and also formation of some non-magnetic phases. The main effects of the above-mentioned factors and the interaction effects with other factors were evaluated quantitatively. The analysis considered the effect of lamping current (175-200 A), pulse duration (10-20 ms) and travel speed (2-10 mm/min) on the coercivity of laser welded samples.

2 citations

Journal ArticleDOI
TL;DR: In this paper, an experimental methodology for determining the surface emissivity curve of a low carbon steel (0.07% C) with 0.21 mm thickness obtained from the productive stock of a continuous annealing line in the steel plant of the Companhia Siderurgica Nacional (CSN).
Abstract: The thermography is an attractive technique to record the real-time temperature during the continuous welding processes. The temperature distribution during the weld zone is essential for understanding and evaluating the metallurgical properties of the joints. The knowledge of the material emissivity curve is necessary for the precise acquisition of thermography data. This emissivity value is usually assumed constant in the thermography software data acquisition, resulting in inaccurate thermographic data. The surface emissivity usually depends on the temperature. Thus, the values obtained in the literature may not be valid for materials of interest under the process’s conditions. Especially in the case of the low carbon steels, the emissivity data available are scarce and frequently obtained at low temperatures (below 200oC). Therefore, we proposed a methodological procedure to measure the effective surface emissivity, which considers the effect of temperatures and surface conditions. This research was focused on the development of an experimental methodology for determining the emissivity curve, using as the sample, a low carbon steel (0.07% C) with 0.21 mm thickness obtained from the productive stock of a continuous annealing line in the steel plant of the Companhia Siderurgica Nacional (CSN). The normal sample emissivity was evaluated in the temperature range from 100oC to 800oC. It was proposed a model based on a sigmoid function to represent the effective emissivity during temperature rise. The sigmoid model parameters were obtained by a fitting procedure using temperature measurements obtained by thermocouples. The results showed an effective emissivity variation as a function of temperature, where emissivity values raged in the interval of 0.09 to 0.83. Thus, the useful emissivity curve was used to correct the thermography data obtained in electrical resistance seam welding (RSEW) with three levels of heats inputs. The correlation for the emissivity curve incorporated in the thermography software was applied to the thermal profiles of the welds analyzed from 441oC to 713oC. These values are consistent with the welding process used. The developed methodology can be applied, in a similar way, in the correction of profiles in other types of welding processes.

2 citations


Cites background from "Welding Metallurgy of"

  • ...Low carbon steels include both carbon sheets of steel with up to 0.15% carbon, so-called low carbon steels, such as those with 0.15% to 0.30% carbon, the so-called mild steels (Kou, 2003)....

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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

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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

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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

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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

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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