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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 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


Cites background from "Welding Metallurgy of"

  • ...(......................................................3/)(16 33* VSL GSG ∆=∆ θπγ According to Kou [144] and Savage [145], growth of the solid in fusion welding is perceived as being initiated by epitaxial growth from the substrate and proceeds by competitive growth toward the center line of the weld....

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  • ...100 the predominant mechanism of solidification in fusion welding is the competitive growth in the weld fusion zone, Kou [144] identified and discussed the details of other mechanisms such as dendrite fragmentation, grain detachment, heterogeneous nucleation and surface nucl eatio that may tend can interrupt and/or dominate the solidification structure in fusion welding....

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  • ...According to Kou [144] and Savage [145], growth of the solid in fusion welding is...

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  • ...Whereas, the predominant mechanism of solidification in fusion welding is the competitive growth in the weld fusion zone, Kou [144] identified and discussed the details of other mechanisms such as dendrite fragmentation, grain detachment, heterogeneous nucleation and surface nucleatio that may tend can interrupt and/or dominate the solidification structure in fusion welding....

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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


Cites background from "Welding Metallurgy of"

  • ...Despite the fact that Schaeffler diagram predicts two phases (austenite plus ferrite) in the FZ of AISI 304 weld nugget microstructure, under rapid solidification conditions such as laser beam welding, a shift in solidification mode may occur.(90) It is generally believed that the change in solidification mode can often result in a fully austenitic microstructure compared to the two phase (ferrite plus austenite) microstructure that is commonly found after primary ferrite solidification....

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  • ...In coarse grained region, which is beside the FZ, both high cooling rate and large austenite grain size coupled with the formation of the carbon rich austenite promote the formation of the martensite.(90) Figure 15 shows the microstructure gradient in TRIP780 RSW....

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  • ...The HAZ in carbon steel weldments can be divided into three distinct subregions: (i) upper critical HAZ (UCHAZ): This region experiences peak temperatures above Ac3 transforming BM microstructure into austenite.(90) Depending on the peak temperature the supercritical HAZ can be divided to the following zones: coarse grained HAZ (CGHAZ) and fine grained HAZ....

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  • ...It is generally believed that the change in solidification mode can often result in a fully austenitic microstructure compared to the two phase (ferrite plus austenite) microstructure that is commonly found after primary ferrite solidification.(90,95,96) Although the change in solidification mode of stainless steel in RSW has not been studied yet, very high cooling rate in RSW process can explain the formation of a fully austenitic weld nugget, as it is the case for laser beam welding....

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  • ...If this temperature is above Mf, there can be untransformed austenite left in the FZ and it can redecompose to untempered martensite upon cooling to room temperature after tempering.(90) For a particular tempering time and tempering current, there is a minimum cooling time to achieve PF mode....

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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


Cites background from "Welding Metallurgy of"

  • ...Solidification crack is one of the most serious defects which occurs widely in welding [27,28], casting [29–31] and additive manufacturing (AM) [32,33], which occurs at the last stage of solidification when liquid films exist between dendrites boundaries where local strains cannot be accommodated by liquid feeding and solid deformation....

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References
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01 Jan 2013
TL;DR: In this paper, the influence of wire speed and current on tensile strength and optical investigation of welded stainless steel with gas metal arc welding (GMAW) was investigated.
Abstract: The objective of this research is to study the influence parameters affecting the mechanical property (tensile strength) and optical investigation (SEM & EDAX) of austenitic stainless steel grade (AISI-304L& AISI-310) with Gas Metal Arc Welding (GMAW). The research was applying the different values of wire speed and current for experiment, which have following interested parameters: welding current at (180, 250 and 320 Amps), welding wire speeds at (2, 3, 5 m/min), shield gas pure CO₂ and (24V)Welding Voltage. The study was done in following aspects: tensile strength and optical investigation. A research study investigate the tensile strength of welding joint is maximum 320.4 N/mm² at wire speed 3m/min and 250 Amps welding current. It has been observed from the SEM analysis that grain of the surface are ultra fine and EDAX analysis conforms the change of chemical composition is small at wire speed 3m/min and 250 Amps welding current.

1 citations

Journal ArticleDOI
Abstract: In manufacturing industry there are many applications for the permanent joint of components of different shapes, but they are also very different in terms of chemical composition and structure [1, 2]. This paper is trying to find technological solutions of assembling by welding of two steels with totally different chemical composition, i.e. carbon steel S235JR + AR and austenitic stainless 316L. The process used for making the heterogeneous joint was Metal Inert Gas (MIG) with flux cored wire, numerically coded 137. The paper presents the effects of welding technology, through heat input, such as hardness. Variations of hardness values determined in the joint areas are presented, as well as the chemical composition of the welded joint obtained using the flux cored wire T 23 12 LPM 1/C1, according to EN ISO 17633 - A.

1 citations

Journal Article
TL;DR: In this article, a structural health monitoring (SHM) technique based on the use of piezoelectric active-sensors, used to determine the structural integrity of stiffened aluminum plates.
Abstract: This paper presents a guided wave structural health monitoring (SHM) technique, based on the use of piezoelectric active-sensors, used to determine the structural integrity of stiffened aluminum plates. For damage detection, the transmitted power between piezoelectric transducers used for Lamb wave propagation is utilized to analyze the extent of damage in the structure. Damage initiation and propagation were successfully monitored with the guided wave technique. Overall, these methods yielded sufficient damage detection capability to warrant further investigation into field deployment. This paper summarizes considerations needed to design such SHM systems, experimental procedures and results, and recommendations that can be used as guidelines for future investigations.

1 citations

Journal Article
TL;DR: In this article, a finite element model was developed to simulate the butt joint, with a 3.2 mm diameter electrode E 7018, of two plates of low carbon and low alloy steel.
Abstract: A finite element model was developed to simulate the butt joint, with a 3.2 mm diameter electrode E 7018, of two plates of low carbon and low alloy steel. Also, the influence on the temperature distribution was studied considering temperature–dependent physical properties (thermal conductivity and specific heat).

1 citations

Dissertation
07 Sep 2017
TL;DR: In this paper, the authors present a table of contents and a list of FIGURES for each of the categories: Table of contents v-vii list of figures viii-ix
Abstract: iv TABLE OF CONTENT v-vii LIST OF FIGURES viii-ix

1 citations