Refrigerated ammonia storage tanks (RAST) are hazardous industrial facilities, where accidents with severe consequences occur. Defects of welded joints are one of the main reasons of RAST accident occurrence. Due to this, during the technical inspection, special attention is paid to quality control of welded joints. The use of non-destructive testing (NDT) for defect detection is essentially important

In the current study a method to determine the location of fracture initiation for non-load carrying fillet welds based on continuous geometry measurements is proposed. Measurements and weld quality evaluation were carried out on welded specimens using the Winteria® software qWeld. One hundred nineteen specimens were produced, scanned, and fatigue tested until failure. The fracture surfaces have been

In this study, brazing experiments were carried out on 6063 aluminum alloy using Al-20Cu-5Si-2Ni filler alloy. Microstructure, mechanical property, and removing behavior of oxide film of the brazed joints were analyzed. The results revealed that the 3% (CsF-AlF3) + 97% (KF-AlF3) non-corrosive flux showed high activity, especially effective removal of oxide films during the brazing process. For the

In this study, the residual stress simulations of the out-of-plane gusset welded joints examined by Leitner et al. (2016) in As-welded and HFMI-treated conditions which are performed by Ruiz (2018, 2019) are reviewed and verified. Based on the reviewed simulation’s results, the changes of residual stress under constant amplitude and compressive spike loads with various stress amplitudes are simulated

In order to produce three-dimensional components from metals, a wide variety of processes exist. Laser processes combined with metal powders are frequently used and developed. Restrictive factors are the machine-related small workspace, the machinery costs and the material portfolio, which place the technology in the area of high-performance components. Wire and arc additive manufacturing (WAAM), as

Graphite was successfully brazed to TZM alloy using the Ti-56Ni, Ti-8.5Si, Ti-33Cr and Ti-30V-3Mo brazing filler materials, respectively, and the corresponding brazing temperatures ranged from 1300 to 1700 °C. The results show that the microstructure of TZM/graphite braze metal was composed of NiTi and Ni3Ti compounds when using Ti-56Ni brazing filler, and the discontinuous TiC compounds were found

Stress distributions in the vicinity of type-b hot spot in the in-plane gusset welded joints and in the free edge of the stiffened cruciform welded joints were evaluated according to the solid model, the fine mesh shell model, and the coarse mesh shell model. The hot spot stress (HSS) of each FE model was evaluated by extrapolating the stresses at the read out point (ROP) to the hot spot position according

The electroslag welding process involves high heat inputs and high deposition rates. In this process, the weld region is surrounded by the base metal and/or devices; therefore, it is difficult to observe the phenomenon and understand the mechanism of weld formation. In this study, we directly observe the molten region formed during the process and construct a numerical model to discuss the phenomena

Conventional manufacturing processes for plastic products, such as injection molding or extrusion, often limit the achievable component geometries. Therefore, it is necessary to join components in order to generate highly complex geometries. Vibration welding is one way of joining components. This process is frequently used and is characterized by short cycle times, high energy efficiency, and the

For high-temperature joining of SiC ceramics, a multi-element AuPdCoMnNi alloy was designed and used as filler metal to join SiC ceramics to metal Mo. The brazing experiment was conducted under the condition of 1150 °C for 5 min and 10 min, respectively. The results show that numerous micro-cracks are visible in the directly brazed Mo/SiC joints, which are continuously distributed in bands of (Co,

An aluminium alloy (AA) cylinder measuring 145 mm diameter (∅) and 11 mm height was produced by wire and arc additive manufacturing (WAAM) using ER4043 filler wire and cold metal transfer (CMT) welding process. The macrostructure examination of the WAAM-processed cylinder revealed excellent bonding between the deposited layers without defects and exhibited superior structural integrity. The tensile

This paper aims to study the effects of different brazing temperatures and holding time on the exposing height of the brazing diamond and wetting angle of the solder, and to analyze the morphology and composition of the reaction products at the interface between the diamond and the solder. Using the Ni-Cr-B-Si composite solder, the orderly arrangement method, the flame spraying process, and the remelting

Martensitic stainless steels are deposited during manufacturing or repair to prolong the service life of a workpiece in a wide variety of industries such as steelmaking. The post-weld heat treatment (PWHT) is necessary to provide appropriate mechanical properties. In this research, a four-layer clad including a buffer and three layers of 13Cr-4Ni-1Mo stainless steel was deposited on AISI 4140 low-alloy

Spontaneous phase transformation in local areas of the austenitic microstructure to martensite with the release of carbides may appear during the manufacturing or operation of engineering products made of two-phase austenitic-martensitic steel grades. When inspecting the quality of products made of these steels, the problem of detecting the local zones of the martensitic phase and carbide precipitation

The relation between the voltage and the arc length in gas metal arc welding (GMAW) is an important characteristic. It determines the power transfer to a large extent, and its knowledge allows the control of the process. However, the voltage depends on a complex distribution of the electric conductivity along the current path and does not depend on the arc length only. A simplified electrical model

In the CO2 welding process, a consumable wire electrode is used and metal transfer phenomena are involved. However, when the arc current is high, the molten wire behavior becomes unstable, and it leads to a large degree of spattering. In this study, a three-dimensional unified model comprising both the arc plasma and the molten wire was constructed, and the behavior of them was visualized using numerical

Laser cleaning technology for pre-weld and post-weld treatments is a promising market due to its high efficiency and consistency, easy operation, and eco-friendly features. The weld quality influence of laser cleaning pre-treatment for the succeeding laser welding of the widely used industrial HSLA steel plates has been investigated in this work. The experimental results show that the laser cleaning

For lateral powder injection, adjustments of defocusing distance, powder feeding angle, and molten pool width are set as input variables, and the powder transport vector, powder outflow position vector, and the injection offset vector are determined. The powder transport model involving above adjustment parameters is constructed based on operation of such vectors, which have been verified in experiments

Among the factors that influence welding defects, arc interruption is an important and unavoidable problem. When the welding torch swings during narrow gap pulsed gas metal arc welding (P-GMAW), arc interruption phenomenon always occurs at the same position along the torch trajectory and is therefore governed by some concrete conditions. Prior to arc interruption, the arc exhibits a distinct shape

Bead-on-plate welding of 6-mm thick AA6061-T6 aluminum alloy is used to characterize the high-frequency (HF) pulse-modulated square wave AC TIG (HFPM AC TIG) welding. The modulation HF pulse reduces the reignition voltage of negative half-wave arc. However, its effectiveness on increasing weld penetration is not evident until the penetration rate (penetration-to-workpiece thickness ratio) exceeds 45%

The eutectic high entropy alloy Nb0.73CoCrFeNi2.1 was manufactured by means of arc smelting and the obtained ingots were cut into 300-μm-thick foils, which were used as filler alloys to braze Crofer 22 APU to Hf-metallized yttria-stabilized zirconia (3YSZ). The brazing process was conducted in a vacuum furnace at 1200 °C for 5 min at a vacuum of 4.3·10–4 mbar. In order to minimize the intense diffusion

A thermo-mechanical simulation of the wire + arc additive manufacturing (WAAM) process is presented in this work. The simulation consists in the deposition of 5 successive layers of 316 L stainless steel on a 316 L base plate. The thermo-mechanical analysis is solved in two dimensions under plane stress assumption. Nonetheless, the metal addition is taking into account in this numerical analysis. An

This study discusses the effects of the addition of Sc and Zr on the microstructure, and mechanical and corrosion properties of an electron beam welded 5083-H15 alloy. The results show that the addition of Sc and Zr to a 5083 alloy exerted a remarkable effect on grain refinement resulting in an enhancement of the mechanical properties. Moreover, the addition of Sc and Zr prompted precipitation of Al3

Wire Arc Additive Manufacturing (WAAM) technology provides opportunities for innovative product design and potential for a more cost effective to additive manufacture than alternative processes. The economics of the technology rely on the deposition rate of the process used. In the past the controlled short-circuit process, known as cold metal transfer (CMT), has been demonstrated to be an effective

In the past few decades, low-temperature metals such as SUS304L, nickel alloys, and high-manganese steels have been widely used for liquefied natural gas (LNG) storage tanks to satisfy the structural integrity requirements at low temperature. Many researchers have conducted studies to characterize the fatigue and fracture performance of low-temperature metals. However, only a limited number of studies

The formability of friction stir welded (FSW) AA7075-O aluminum alloy sheet specimens was tested under a range of warm uniaxial and biaxial loading conditions. To study the effect of FSW process conditions on formability, four groups of specimens were prepared using a range of FSW parameters. Two rotational speeds (500 and 1000 rpm), four travel speeds (4.2, 5.1, 8.5, 12.7 mm/s), and four axial force

In this study, Linear Elastic Fracture Mechanics (LEFM) approach is used to evaluate the fatigue strength of a box-shaped welded structure. A parametric study is also undertaken to study the effect of various weld parameters on the fatigue strength, such as lack of weld metal penetration, load position, and plate thicknesses. FRANC3D software was adopted to obtain the stress intensity factor values

This study aimed to investigate the design S-N curve on the basis of the hot spot stress (HSS) approach considering proper thickness effect for welded aluminum joints. The effect of the main plate thickness is examined by using the results of fatigue tests in this study and references of fatigue data of previous literature. The fatigue tests are performed on 5083-O welded joint specimens with four

The possibilities and challenges of using fiber optical sensors to monitor the laser-assisted joining of metal–polymer joints have been described in this article. Fundamental investigation proves the basic suitability of the measuring method for this application and studies the effect of essential influencing variables of the joining process—e.g., the clamping force—on the resulting sensor signals

This paper describes an investigation into the effect of insufficient homogenization of pigmented resin in polyethylene (PE) pipes on the integrity of the subsequent butt fusion joints and the development of a test to quantify the amount of windows in the pipe. Analysis was carried out on a number of PE pipes, made using both pre-compounded and in-line compounded resin on the same pipe extruder but

Mixed joints made of aluminium and copper are increasingly important in industrial applications. This type of mixed joint is of interest, e.g. when good electrical and thermal properties, as in power electronics cooling, are required. The joining requirements consist of the formation a metallurgical bond and planar joint between aluminium alloys and copper. The fluxfree vacuum brazing process is considered

Full-penetration butt welds are often specified to connect the beam flanges to the column flange in welded moment resisting connections. Partial-penetration butt welds are cheaper than full-penetration butt welds and also more cost effective when compared to large fillet welds. EN 1993-1-8 standard includes a definition of an “effective full penetration of T-butt welds” implying that it can be used

A recommendation for the application and fatigue assessment of the HFMI post-treatment was published by the IIW in 2016. Recently, the therein recommended HFMI design curves in case of constant amplitude loading (CAL) were validated involving test data with different base material yield strengths, increased plate thicknesses, and elevated load ratios. Continuative to this previous work, this paper

Large tensile strains acting on the solidifying weld metal can cause the formation of eutectic bands along grain boundaries. These eutectic bands can lead to severe liquation in the partially melted zone of a subsequent overlapping weld. This can increase the risk of heat-affected zone liquation cracking. In this paper, we present a solidification model for modeling eutectic bands. The model is based

This paper presents the evaluation of two promising non-destructive testing (NDT) methods for the inspection of additively manufactured (AM) parts: a resonant acoustics method (RAM) and a phased array ultrasonic testing (PAUT) method involving a full matrix capture (FMC) acquisition procedure and a total focused method (TFM) to post-process the data and reconstruct the images. The two methods were

Wire- and arc-based additive manufacturing (WAAM) is a promising technology for large-scale additive manufacturing of metallic components. However, due to the high heat input by the electric arc, interpass cooling time decelerates the average manufacturing speed. Since future applications aim to the production of large structural steel components, the manufacturing speed is a key parameter to make

We successfully used CoCrW alloy as the feedstock for directly shaping wear-resistant products by additive manufacturing. We present a guideline for forming substantive, high-density, crack-free CoCrW alloys via laser metal deposition (LMD) and evaluated the relationship between the microstructure and mechanical properties. CoCrW alloy with a scale of several tens of cubic centimeters has not been

The thermal efficiency of arc welding influences the cooling rate, peak temperature, and microstructures of a weld, which affects the material properties of the welded joint. This work quantifies the uncertainty of thermal efficiency measurements on gas metal arc welds using low (2.5 kW) and high (9.5 kW) arc powers. In order to understand the effect of calorimeter parameters on the measured efficiency

Induction brazing is widespread in many industries due to its ability for local contactless heating as well as its high heating rates and the associated short cycle times. As a result of these advantages, this brazing process is particularly widespread in the tool industry for mass products made of cemented carbide/steel, for example, in saw blades or milling tools. The state of the art is the use

The concept of brittle crack arrest has recently become an internationally focused issue for container ships. The International Association of Classification Society (IACS) also prescribed the unified requirement (UR) for brittle crack arrest design, and brittle crack arrest design has been internationally authorized. As one of the methods to evaluate brittle crack arrestability, the crack arrest temperature

In this study, A7204-T4 aluminum alloy sheet with a thickness of 6 mm was welded using fiber laser variable polarity tungsten inert gas (VPTIG) hybrid welding with ER5356 filler wire, during which Nb (niobium) foils with different thicknesses (10 μm, 25 μm, 35 μm, and 50 μm) were preset between the butt joint faces. The joint microstructure and properties with different Nb content were investigated

Currently used approaches for the modeling of the heat input in gas metal arc (GMA) welding process simulation usually assume an axisymmetrical Gaussian distribution of heat flux in the cathode region. However, as in GMA welding, cathodic electron emission of non-refractory metals is involved; the attachment region consists of multiple highly mobile cathode spots, which have a highly concentrated current

Refill friction stir spot welding (RFSSW) is a highly flexible and promising solid-state joining method for aluminium alloys. Alternatively, resistance spot welding (RSW) can be stated as an appropriate joining method which can be automated and used within a high-volume production due to short process times. Both processes do not need any additional elements and a flat surface on both sides of the

The ultrasonic joining process was recently introduced as an alternative concept to join through-the-thickness reinforced metal-composite hybrid structures. In this work, the investigation of joining process parameters effect on the joint mechanical performance of Ti-6Al-4V-glass-fiber-reinforced polyetherimide overlap joints was carried out by Box-Behnken design of experiments. The individual and

Wire and arc additive manufacturing (WAAM) technology is growing in interest in the last years. The technology enables the manufacturing of real geometries by overlapping weld beads and is well suited for metallic parts with high buy-to-fly ratio. Manufacturing costs and time are critical issues which determine the business case. Therefore, it is necessary to develop strategies that minimise the production

In the past, most approaches to reduce welding fume emissions were primarily based on welding consumables, whereas in the context of the present work, a new concept with direct reference to the welding process technology is pursued. Many other measures to improve occupational health and safety, such as use of extended personal protective equipment (e.g., forced air ventilated helmets) and extraction

Additive manufactured (AM) lattice structures have become very prominent in recent times especially in air and spacecraft industry for their lower weight and specific mechanical properties. Their stiffness and strength can be controlled by their geometrical properties, such as the shape and dimensions of the unit cell. Geometrical and dimensional accuracy of the AM lattices is therefore one of the

This paper presents the influence of welding current, electrode-workpiece distance, electrode composition, electrode diameter, electrode tip angle, shielding gas composition, and pulsed current frequency over the arc stagnation pressure of gas tungsten arc welding (GTAW). In this study, arc application tests were carried out over a 1-mm diameter hole on a non-melting water-cooled copper plate. The

This study investigated the applicability of low transformation temperature (LTT) arc welding consumables to improve fatigue strength against weld root failure. Transverse attachment joints formed by single-sided welding, similar to rib-to-deck connections in orthotropic steel bridge decks, were fabricated using an LTT welding consumable and conventional welding consumable. Fatigue tests were performed

The aluminothermic welding (ATW) process is the most commonly used welding process for welding rails (track) in the field. The large amount of weld metal added in the ATW process may result in a wide uneven surface zone on the rail head, which may, in rare cases, lead to irregularities in wear and plastic deformation due to high dynamic wheel-rail forces as wheels pass. The present paper studies the

The publication of this article unfortunately contained a mistake. Table 8 of Appendix B was not correct; please see the updated table below.

In 2016, the International Institute of Welding (IIW) published a recommendation for high-frequency mechanical impact (HFMI) treatment for improving the fatigue strength of welded joints. Since the publication of the HFMI recommendations, numerous of studies have been published with a considerable amount of new fatigue test data focusing on various aspects of the improvement; influence of base material

Unlike other joining techniques, laser transmission welding offers unique advantages such as selective and contactless energy deposition. This enables the fabrication of flexible seam geometries at low mechanical and thermal stresses. However, the use of absorbing additives for the lower joining partner such as carbon black is crucial as most polymers are transparent in the spectral range of typical

In this paper, T-joint samples in a 1300 MPa yield strength steel were produced using conventional or low transformation temperature (LTT) type consumables. The welded samples were either subjected to high-frequency mechanical impact (HFMI) treatment or to shot-peening. Fatigue testing was performed under fully reversed, constant amplitude bending load. Shot-peening gave a significant increase in fatigue

A model was established for four-element material with HCP structure by EET. The filler of TiZrCuNi was analyzed by the model. It was found that Ni element is beneficial for the strength of the filler but Cu element is beneficial for the ductility of the filler. It showed that controlling the amount of Cu and Ni with the proper distribution of them was important. Compared with the filler Ti-13Zr-22Cu-9Ni

The purpose of this study was to evaluate the microstructural evolution of softened zones after cyclic plastic deformation (CPD) and the effect of CPD on the mechanical properties of X60 reeled-pipeline welded joints. The results showed that the existence of softened zone caused the deformation to be mainly concentrated in this area during CPD process. The minimum hardness of softened zone was 18 HV

This paper deals with the stress analysis of a cantilever box beam subjected to static or fluctuating torsional moment loading. Such beams may have multiple critical locations from the strength point of view; one interesting detail is the cross section where the loading is imposed. However, such details can be typically designed to possess smooth shapes, resulting in moderate stress concentrations

This paper proposes an estimation method for crack tip opening displacement (CTOD) in laser welds. The theoretical model for CTOD estimation developed by Dugdale and Bilby et al. (DBCS model) was used for laser-welded plates. The yield stress of the laser weld metal and narrow hard zone width affected the CTOD, and the correction of yield stress by using the DBCS model to obtain a suitable CTOD estimation

The objectives of this study are: (1) to verify whether using linear heat input alone is sufficient to predict the resulting microstructure of Ti6Al4V and (2) to demonstrate the potential of single-step process of functionally graded material using powder bed fusion. In laser powder bed fusion, linear heat input is defined as the ratio of laser power to scan speed. It is a key process variable that

The present investigations on generative manufacturing using metallic materials pursue the idea of transferring the microscopic structural morphology of a dual-phase steel in modified form to the macroscopic level. The aim is to be able to join materials of different lattice modifications and to combine their positive properties. This applies in particular to the combination of high tensile strength