Welding Metallurgy - Science topic

This study presents a comprehensive investigation into optimizing Tungsten Inert Gas (TIG) welding parameters to enhance the mechanical performance of the widely used Al-6061 T6 alloy, specifically in a double V joint configuration with a plate thickness of 6 mm, for aerospace applications. The Taguchi method was employed to design the experiments,...

This paper introduces a comprehensive framework aimed at ensuring quality assurance in welding procedures within the construction sector. The framework encompasses the adoption of standardized Welding Procedure Specifications (WPS), rigorous training and certification processes for welders, and the integration of state-of-the-art technologies such...

Micro plasma arc welding (MPaW) is frequently used for joining thin sheets of ferrous and nonferrous materials. In this study, austenitic stainless steel 316l of 0.5 mm thin sheets are joined by using MPaW. The weld metallurgy is characterized by field electron scanning microscopy (FESEM), Transmission electron microscopy (TEM), and X-ray diffracti...

Dissimilar welds between ferritic and austenitic steels represent a good solution for exploiting the best performance of stainless steels at high and low temperatures and in aggressive environments, while minimizing costs. Therefore, they are widely used in nuclear and petrochemical plants; however, due to the different properties of the steels inv...

Dear Dzevad Hadzihafizovic, We are happy to have received your submission, Welding Metallurgy Crystallization of Metals in Welded Joints Epitaxial Crystallization - Directed Crystallization, which is now posted as a preprint on SSRN. Hadzihafizovic, Dzevad, Welding Metallurgy Crystallization of Metals in Welded Joints Epitaxial Crystallization -...

Underwater Shielded Metal Arc Welding (SMAW) is highly affected by the welding depth. The arc and molten metal in contact with the surrounding environment cause operational and metallurgical challenges regarding arc stability, metal transfer, gas formation, high-cooling rates, and diffusible hydrogen uptake. The hydrostatic pressure causes losses i...

Dissimilar welds between ferritic and austenitic steels represent a good solution for exploiting the best performance of stainless steels at high and low temperatures and in aggressive environments, while minimizing costs. Therefore, they are widely used in nuclear and petrochemical plants, however, due to the different properties of the steels inv...

In the present study, dissimilar metals such as austenitic stainless steel (ASS) and duplex stainless steel (DSS) with a thickness of 2 mm are joined by resistance spot welding process to investigate the welding metallurgy and failure behavior under different heat inputs. Non-uniform electrode impressions are observed on ASS and DSS sides due to th...

The purpose of this study is to investigate the transfer behavior of oxygen during the submerged arc welding process using CaF2-SiO2-CaO fluxes. In contrast to previous research that only focused on the final oxygen content in the final weld metal, this study introduces two new parameters, ΔdO and ΔwO, to quantify the oxygen transfer in essential r...

In this study, friction stir welding was carried out with varying tool rotational speed from 300 to 750 rpm at a fixed tool traverse speed of 60 mm/min and 2° tool tilt angle. The main aim of this work is to investigate the influence of the tool rotational speed on the welding metallurgy, mechanical property, and electrochemical behavior of frictio...

Heterogeneous nucleation takes place at higher temperatures, because the maximum random fluctuation of 100 atoms gives a larger crystal radius if the atoms are arranged as a spherical cap. It is easy to estimate undercooling that we should get heterogeneous nucleation with a contact angle of 10°, this means that heterogeneous nucleation always "win...

Welding metallurgy Crystallization mechanisms in the welding process Constitutional liquation mechanism by Savage W. F. Epitaxial crystallization Epitaxial crystallization - epitaxial crystallization Regardless of the type of fusion welding process considered, some dilution always occurs in the weld area (Figure 2.5). In fact, it is extremely impo...

Crystallization of metals in welded joints Epitaxial crystallization

The hydrocarbon industry constantly requires a better understanding of stainless-steel welding metallurgy. Despite the fact that gas metal arc welding (GMAW) is one of the most commonly employed welding processes in the petrochemical industry, the process is characterized by the presence of a high number of variables to control in order to obtain c...

The quality of spot welds between galvanized dual phase steels of 590 MPa (DP590Z) and Al–Si coated press-hardening steels (PHS) of 22MnB5 (PHS1500AS) are determined by welding metallurgy of both base metal and the coating. In this study, extending the dwelling time between two pulses is proposed to suppress splash in the broad process window of we...

To develop in-depth understanding of metallurgical phenomena for completeness, mechanical heterogeneity is kinetically and thermodynamically explained by thorough microstructure characterization of engineering materials, e.g. polycrystalline nickel-based superalloy, for alleviation of weldability-related problems during laser-induced keyhole fabric...

From a thermodynamic perspective, the present study has been performed to investigate the effect of SiO2 level in agglomerated fluxes on the element transfer behavior of essential elements, by applying CaF2-Na2O-SiO2 agglomerated fluxes with varying SiO2 contents. Element transfer behavior is quantified by the Δ value. The impact of SiO2 and heat i...

Describe basic metallurgical principles including strengthening mechanisms Describe the basic concepts of welding metallurgy, microstructure influences on properties and weldability Understanding different types of carbon and low alloy steels, stainless steels, nickel alloys including microstructure development and weldability issues of each alloy...

Welding metallurgy - Mechanisms of crystallization in the welding process, Constitutional liquation mechanism by Savage W. F.

An overview of welding methods and process parameters and its effects on mechanical behaviour and structural integrity of magnesium and its alloys are discussed. These alloys are less dense and beneficial structural alloys for improved energy efficiency, eco-friendliness and driver of circular economic model for sustainable design and innovative ec...

Achieving a higher quality in wire arc additive manufacturing (WAAM) is a result of the development of welding metallurgy, the development of filler wires, and the control of the thermophysical properties of the electric arc. In this paper, the authors developed composite wires for WAAM with a Ni-LaF3, Ni-LaB6 coating. The addition of LaF3, LaB6, a...

Q345 steel is a low-alloy high-strength steel that is widely used in production. As the solid-state phase transition of Q345 steel is very sensitive to temperature, the microstructure and hardness of joints fabricated with this steel are difficult to predict. Therefore, studying the welding metallurgy, residual welding stress, and welding deformati...

The arc welding process is the main fusion welding process used in the offshore industry. This thesis attempts to understand the residual stress and distortion issues attributed to welding, and the study aims to bring a sense of value, purpose, and relevancy to academic scholarship and industrial application. Welding-induced residual stresses and d...

High-entropy alloys (HEAs) and compositionally complex alloys (CCAs) represent new classes of materials containing five or more alloying elements (concentration of each element ranging from 5 to 35 at. %). In the present study, HEAs are defined as single-phase solid solutions; CCAs contain at least two phases. The alloy concept of HEAs/CCAs is fund...

Evolution of microstructure and room-temperature strength of G115 deposited metal after different tempering at 760°C,800°C and 820°C have been experimentally investigated using metallographic microscope, field emission scanning electron microscopy (SEM) and tensile test, charpy impact test. The results show that after tempering at 800 °C, the G115...

Development of welding consumables with fluorides and borides of rare earth metals is a promising area for improving the weldability of low alloy steels. As lanthanum fluoride and boride dissociate, lanthanum and boron dissolve in the weld pool and the welding arc plasma is saturated with fluorine. As a result of FeO, MnO, SiO2 deoxidation and FeS,...

Welding Metallurgy

Hardening of welded joints occurs under nonequilibrium conditions and must be studied from both a macroscopic and a microscopic point of view. Macroscopic hardening will be considered at the rear edge of the welded pool and along the boundaries of the solidification grain (SGB - Solidifcation Grain Boundary). From the point of view of redistributio...

High strength low alloy steels are employed in structural elements and, despite presenting good weldability, the welded joint is always a critical issue and its evaluation is fundamental in guaranteeing structural integrity. The mechanical properties of weld beads can be significantly different from the base material’s properties due to metallurgic...

Epitaxial crystallization Regardless of the type of fusion welding process considered, some always occur in the weld area (Figure 2.5). In fact, it is extremely important that the dilution occurs, because it is the only way to ensure that the surface of the base metal in contact with the liquid metal for welding is clean, ie. free of oxide films or...

At present, most Mo2FeB2-based cermets are prepared by vacuum sintering. However, vacuum sintering is only suitable for ordinary cylinder and cuboid workpieces, and it is difficult to apply to large curved surface and large size workpieces. Therefore, in order to improve the flexibility of preparing Mo2FeB2 cermet, a flux cored wire with 70% fillin...

Long rails, welded by the Flash-Butt Welding process present desirable characteristics concerning the dynamic behavior of the track, however flash-butt-welded joints are regions of structural and mechanical discontinuity where high residual stresses originate, and, consequently, premature-fatigue failures may take place. This paper employs dilatome...

This paper presents high quality (2048 x 1532 pixels) Light Microscope steel images sampled from the welding fusion zone. The microstructure images were acquired from the Design of Experiments (22 full factorial design) planned to compare two different arc welding processes at two different arc welding energies. The 400 raw images appear as they we...

The purpose of this case study is to determine the cause of failure of DIN 1.4435 BN2 (AISI 316L with very low ferrite contents) clamp ferrules applied in pharmaceutical systems. Leakage was observed during operation in the clamp pipe connections of the ultra-pure fluid delivery systems. The surface of clamp ferrules showed remarkable discoloration...

Pores and cracks are known as the main defects in metal additive manufacturing (MAM), including directed energy deposition(DED). A gaseous fume is often produced by laser flash (instantaneous high temperature) during laser processing, which may cause various defects such as porosity, lack of fusion, inhomogeneity, low flowability and composition ch...

Fabrication and welding of structural superalloy components for aero-engines, land-based gas turbines as well as for the energy sector (i [...]

Dear all, I'm guest editing a special issue on Welding Metallurgy and Weldability of Superalloys. Looking forward to see many submissions. Best Joel

The objective of this review regarding the catastrophic failure of an important welded structure, the Alexander L. Kielland platform, was to indicate that the investigation team should have comprised and involved an experienced welding engineer. Lack of involvement of the welding engineer can lead to misinterpretation of the evidence which results...

The extensive use of galvanized interstitial-free (IF) steels in the automotive industry makes their resistance spot welding (RSW) metallurgy important. In this study, the relationships between microstructure, macrostructure, mechanical performance, and failure mode of resistance spot welds of galvanized IF steels were investigated. In order to cha...

Resumo Trilhos longos, soldados pelo processo Flash Butt Welding (FBW), são a realidade das ferrovias brasileiras de média e alta carga por eixo. Embora apresentem características desejáveis do ponto de vista do comportamento dinâmico da via, as soldas são regiões de descontinuidade estrutural e mecânica onde se originam tensões residuais, e que es...

Resumo A soldagem de alto aporte térmico é uma alternativa que tem sido empregada na indústria naval e de petróleo para reduzir o número de passes de soldagem em estruturas espessas por meio do aumento da taxa de deposição. Isso tem levado desenvolvimento de aços e de consumíveis que permitem a obtenção de juntas com aceitável nível de tenacidade n...

Any mechanical structure or system weather be it a bridge,dam,mechanized tools or any sort of machine that helps to reduce human efforts demands high quality materials which must impose strength,reliability and ductility for better construction.It must also possess adequate elasticity and plasticity properties and many several other properties whic...

Hot cracking often refers to the appearance of liquid films along grain boundaries or to another place in the weld metal structure. Despite hot cracking importance in alloy weldability, there is limited understanding of the influencing mechanisms. Theories and criteria worked out over the years to assess alloy weldability will be presented. The rev...

Degradation of dissimilar metal welds in the piping systems of power plants is recognized as a significant ageing factor. Hence, close scientific attention is paid to various degradation mechanisms concerned with dissimilar metal welds, as well as to welding metallurgy. However, the process of dissimilar metal weld refurbishment consisting of the w...

Welding is a widely used process, in the fabrication industries. Different welding processes are use in the manufacturing of automobile bodies, construction industry, aviation industry, refineries, pipeline fabrication and general machine repair work. With considering importance of welding and its application, this present study helps to understand...

Heat input during welding metal fusion generates different transformations, such as grain growth, hydrogen cracking, and the formation of brittle structures, generally associated with the heat-affected zone (HAZ). For this reason, it is very important to know the behavior of this area before welding. This paper presents a study of the thermal behav...

This paper investigates the metallurgical and mechanical response of 2304 duplex stainless steel — as an interesting candidate for automotive body­in­white applications — to resistance spot welding. The results showed the high cooling rate associated with the resistance spot welding process suppressed the postsolidification ferrite­austenite transf...

The mass saving potential of lightweight materials , such as Al alloys, is beneficial for fuel economy and reducing CO 2 emissions. However, the widespread use of these alloys has been long hindered due to the difficulty in fusion joining as well as their high cost. Welding of Al alloys, which are considered to be difficult to weld through conventi...

Resumo Trilhos com perfil TR-57 do tipo intermediário foram soldados por centelhamento em um estaleiro brasileiro e passaram por detalhada caracterização mecânica e metalográfica. Os dados quantitativos da caracterização metalográfica e dos ensaios mecânicos foram submetidos a análises de variância (ANOVA). Na metalografia confirmou-se a presença m...

The increasing demand for ultra-high strength steels in vehicle manufacturing leads to the application of new alloys. This poses a challenge on joining especially by fusion welding. A stainless high manganese steel sheet with excellent strength and deformation properties stands in the centre of the development. Similar and dissimilar welds with a m...

The paper addresses the process–microstructure–performance relationships in resistance spot welding of a martensitic advanced high strength steel. Significant softening was observed in the heat affected zone (HAZ) due to allotriomorphic ferrite formation in the inter-critical HAZ and tempering of martensite in sub-critical HAZ (SCHAZ), with the lat...

Microsegregation occurs during solidification of fusion zone in alloy C-276. The concomitant precipitation of topologically close-packed phases P and μ has been reported to be responsible for the hot cracking observed in this alloy during welding. The clue to preventing hot cracking hence lies in suppressing microsegregation in the fusion zone. An...

A Virtual Machine has led to a fully automatic spot welding system. All necessary parameters are created by measuring systems and algorithms running in the Virtual Machine. A hybrid operating circuit allows the Virtual Machine to read the exact process voltage between the tips of the electrodes every 50 µs. Actual welding voltage and current allow...

In the study mercury displacement method was used for determination of diffusible hydrogen amount in deposited metal obtained during underwater wet welding with covered electrodes in laboratory conditions according to a two-level full factorial design for three factors. The factors and their levels were chosen among conditions and parameters of wel...

In these conference proceedings we present papers from the 6th International Scientific Practical Conference on Innovation Technology and Economics in Engineering held at the Yurga Institute of Technology branch of the National Research Tomsk Polytechnic University from 21st – 23rd May 2015. The proceedings contain the selected scientific reports s...

This paper addresses the microstructure and mechanical performance of dissimilar resistance spot welds between AISI 430 ferritic stainless steel and drawing quality special killed (DQSK) low-carbon steel. The mechanical properties of the welds are described by peak load, failure energy, and failure mode during the tensile-shear test. Phase transfor...

Wayne Thomas has worked in research and development since 1983. Formerly, principal research engineer, for TWI Ltd, up to 2007. Currently Managing director, of Co-tropic Ltd, from March, carrying out independent research and development into dispersible fibre and composite rebar reinforcement for composite and concrete matrix materials. He has a de...

The effect of heat input on microstructural zones, hardness and fracture of T-joints in EN S235JR carbon steel was evaluated using the Vickers hardness, SEM, and fractography on impact fractured specimens. The gas metal arc welding (GMAW) process with pulsed metal arc transfer and different welding speeds was performed by an industrial robot using...

Many applications for Ni-base alloys require the usage of a welding or joining process before the component can be placed into service or for a repair procedure after the component has already seen service. Fabrication or repair can be achieved with a wide variety of welding processes and alloys as long as the process, process parameters, and metal...

A new class of steels is going to be introduced into sheet manufacturing. Stainless ferritic and martensitic steels open up opportunities for sheet metal fabrication including hot stamping. Strengths of up to 2 GPa at fracture elongations of 15% can be attained through this. Welding of these materials, as a result, became a challenge. Energy-reduce...

Different Fe-X-Ti weld overlays were deposited using the controlled short-circuit gas metal arc welding (CSC-GMAW) process alone or in combination with the pulsed gas tungsten arc welding (GTAW-P) process. The overlays were characterized before and after postweld heat treatment (PWHT) using optical and scanning electron microscopy, electron probe m...

The widespread application of nickel-based alloys as structural materials in chemical, nuclear and power generation industries is often limited due to weldability issues. Technological and metallurgical problems such as lack of fusion or hot cracking require specific welding guidelines as well as knowledge of the welding metallurgy to produce welds...

Aluminium alloys are important alloys in industries today, due to their ductile, lightweight and malleable nature. Research into how to effectively weld such alloys is therefore becoming increasingly important because of the considerable advantages of the material. Utilizing the high strength-to-weight ratio of aluminium alloys in welded products r...

In welded pipe joints of austenitic stainless steel, the mismatch of residual stress distribution often occurs between a variety of measurement method and the numerical simulation. It is especially known that non-destructive measurement such as X-ray diffraction method makes remarkable different due to the microstructure evolution by the welding. M...

Weldability of ultra low carbon and nitrogen, low chromium ferrite stainless steel is analysed by using Thermol-cal software and welding metallurgy. Eembrittlement of welding joint is the failure reason during application of ultra low carbon and nitrogen 12% chromium FSS. Comparing welding joint performance of different welding process, Gas Metal A...

Purpose: Present work was aimed at developing welding technology applicable for hot and cold rolled strips made of high alloy martensitic steels. Electron beam (EB) and TIG welding processes parameters were worked out for strips of the 2N11K13H3M, N19M4T, H11N10M2T and PH13-8 steel grades (unconventional maraging and precipitation hardening stainle...

The trend of the welding technology of lightweight alloys such as aluminum alloy and magnesium alloy has been studied. The lightweight alloys in the automobile, high-speed light aircraft and modern aerospace industry can reduce vehicle weight, while stringently demanding the high quality and efficienct welding techniques, to produce the best weldme...

Over the past century, the principal method for estimating the sequence of microstructural events that produce the final weld microstructure has been postweld microstructure analysis, and it's the interpretation of these microstructures that sets welding metallurgy apart from other related endeavors. In conjunction with heat flow analysis and therm...

Duplex stainless steels (DSS) as alternatives to conventional austenitic stainless steels for the construction of pipelines is becoming more wide-spread, particularly for sour service applications where corrosion resistance / stress corrosion cracking resistance is required in aggressive chloride / sulphide environments. While these steels show man...

A fine-grained microstructure yields the optimum combination of strength and toughness of steel. Refinement of the ferrite microstructure by formation of fine intra-granular acicular ferrite nucleated on inclusion has been caused wide interesting in weld metallurgy and other metallurgy fields. It is also important to refine the as-cast microstructu...