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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 paper, a scientific investigation on controlling the brittle phase formation during laser dissimilar welding of high-carbon steel to stainless steel was conducted, and a new heat treatment strategy was proposed and evaluated using a finite element analysis-based numerical simulation model.
Abstract: Laser welding is becoming an important joining technique for welding of stainless steel to carbon steel and is extensively used across various sectors, including aerospace, transportation, power plants, electronics and other industries. However, welding of stainless steel to high-carbon steel is still at its early stage, predominantly due to the formation of hard brittle phases, which undermine the mechanical strength of the joint. This study reports a scientific investigation on controlling the brittle phase formation during laser dissimilar welding of high-carbon steel to stainless steel. Attempts have been made to tailor the microstructure and phase composition of the fusion zone through influencing the alloying composition and the cooling rate. Results show that the heat-affected zone (HAZ) within the high-carbon steel has significantly higher hardness than the weld area, which severely undermines the weld quality. To reduce the hardness of the HAZ, a new heat treatment strategy was proposed and evaluated using a finite element analysis-based numerical simulation model. A series of experiments has been performed to verify the developed thermo-metallurgical finite element analysis (FEA) model, and a qualitative agreement of predicted martensitic phase distribution is shown to exist.

24 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of rapid heating and cooling rates associated with welding thermal cycles on the phase transformations and microstructures, specifically in the heat-affected zone, were determined using dilatometry, microhardness, and micro-structural characterization.
Abstract: 10 wt pct Ni steel is a high-strength steel that possesses good ballistic resistance from the deformation induced transformation of austenite to martensite, known as the transformation-induced-plasticity effect. The effects of rapid heating and cooling rates associated with welding thermal cycles on the phase transformations and microstructures, specifically in the heat-affected zone, were determined using dilatometry, microhardness, and microstructural characterization. Heating rate experiments demonstrate that the Ac3 temperature is dependent on heating rate, varying from 1094 K (821 °C) at a heating rate of 1 °C/s to 1324 K (1051 °C) at a heating rate of 1830 °C/s. A continuous cooling transformation diagram produced for 10 wt pct Ni steel reveals that martensite will form over a wide range of cooling rates, which reflects a very high hardenability of this alloy. These results were applied to a single pass, autogenous, gas tungsten arc weld. The diffusion of nickel from regions of austenite to martensite during the welding thermal cycle manifests itself in a muddled, rod-like lath martensitic microstructure. The results of these studies show that the nickel enrichment of the austenite in 10 wt pct Ni steel plays a critical role in phase transformations during welding.

24 citations


Additional excerpts

  • ...Typically, the regions of the HAZ would be identified according to standard HAZ terminology for steel welds that include the sub-critical (SCHAZ), ICHAZ, fine grain (FGHAZ), and coarse grain regions (CGHAZ),([4]) and these regions are quite easy to identify in carbon and low alloy steels.([51]) However, the HAZ microstructures in 10 pct Ni steel are slightly more complex due to the sluggish transformation kinetics, so despite the regions being present, only some of them can be distinguished purely by microstructure....

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Journal ArticleDOI
TL;DR: The solidification cracking susceptibility of aluminium alloys 2024, 2219, 6061 and 7075 was evaluated by the transverse motion weldability test as discussed by the authors, where the lower sheet moved in a transverse di...
Abstract: The solidification cracking susceptibility of aluminium alloys 2024, 2219, 6061 and 7075 was evaluated recently by the transverse motion weldability test (the lower sheet moved in the transverse di...

24 citations

Journal ArticleDOI
TL;DR: In this paper, the evolution of crystallographic orientations in a maraging stainless steel (commercially known as stainless steel CX) sample fabricated by the selective laser melting (SLM) process was studied through experimental and modelling approaches.
Abstract: Due to high local cooling rates and non-equilibrium directional solidification conditions, selective laser melting (SLM) processed metals exhibit microstructural and textural features significantly different from the conventionally processed ones. The evolution of crystallographic orientations in a maraging stainless steel (commercially known as stainless steel CX) sample fabricated by the SLM process was studied through experimental and modelling approaches Electron backscattering diffraction analysis showed that the dominant texture components in martensite and austenite phases are || building direction and || building direction, respectively. Texture simulation indicated that the formation of crystallographic orientations in the studied sample is the result of two consecutive phase transformations, from initially solidified delta ferrite phase with dominant cube fiber texture to austenite and austenite to martensite.

24 citations

Journal ArticleDOI
TL;DR: In this article, an attempt has been made to model the temperature distribution during submerged arc welding process using finite element modeling technique implemented in ANSYS v12 In the present analysis, heat source is assumed to be double-ellipsoidal with Gaussian volumetric heat generation Furthermore, variation of material properties with temperature and both convective and radiant heat loss boundary condition have been considered The predicted temperature distribution is then validated against the experimental results obtained by thermal imaging of the welded plate, and they are found to be in a good agreement
Abstract: Temperature distribution during any welding process holds the key for understanding and predicting several important welding attributes like heat affected zone, microstructure of the weld, residual stress, and distortion during welding The accuracy of the analytical approaches for modeling temperature distribution during welding has been constrained by oversimplified assumptions regarding boundary conditions and material properties In this paper, an attempt has been made to model the temperature distribution during submerged arc welding process using finite element modeling technique implemented in ANSYS v12 In the present analysis, heat source is assumed to be double-ellipsoidal with Gaussian volumetric heat generation Furthermore, variation of material properties with temperature and both convective and radiant heat loss boundary condition have been considered The predicted temperature distribution is then validated against the experimental results obtained by thermal imaging of the welded plate, and they are found to be in a good agreement

24 citations


Cites background from "Welding Metallurgy of"

  • ...However, at very high welding currents, AC is preferred in order to minimize arc blow [2]....

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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

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