Weld Research Papers - Academia.edu (original) (raw)

Top Papers
Most Cited Papers
Most Downloaded Papers
Newest Papers
People
- by
- •
- Materials Engineering, Mechanical Engineering, Microstructure, Materials
- by Dario de Blasiis
- •
- Engineering, Ultraviolet, Quality assessment, Infrared

Submerged Arc Welding (SAW) is a common arc welding process which is used to join thick and heavy sections. The basic characteristics of this process are high deposition rate, ability to weld thick sections with ease and longer weld runs. The study of weld bead geometry is important, as it determine the stress carrying capacity of a weld. For the same reason, this paper highlights the analysis and study of process parameters: arc Voltage, welding current, travel speed and electrode extension, on the bead geometry response such as, bead height, bead width and bead penetration. Design Expert 8.0 with 4 factors, 5 levels, rotatable Central Composite Design. was used to develop relationship for predicting weld bead geometry, which enables to quantify the direct and interaction effects. Mathematical models prepared for the submerged arc welding of 16mm thick mild steel by using response surface methodology which co relate the process variables with the bead geometry characteristics then ...

- by uma gautam
- •
- Materials Science, Response Surface Methodology, Weld, Central Composite Design
- by Radovan Kovacevic
- •
- Mechanical Engineering, Feasibility Study, Friction Welding, Porosity
- by Philippe A GILLES
- •
- Microstructure, Heterogeneity, Crack propagation, Weld
- by Jonathan Parker
- •
- Materials Engineering, Mechanical Engineering, Creep, Weld

This paper presents the failure analysis of AISI-304 stainless steel tank that was fabricated by welding and used for the storage of styrene monomers. After about 13 years of satisfactory operation, significant cracking was observed adjacent to the weld joints and in base plate near tank foundation. Weld repair was by shielded gas arc welding using AISI 308 stainless steel filler

- by Aashish Shah
- •
- Engineering, Computer Aided Design, Modeling, Finite element method

El presente articulo describe el desarrollo de un metodo experimental empleado para construir las curvas de Corriente de Soldadura Vs. Velocidad de Alimentacion de Alambre en proceso GMAW, con dos extensiones de electrodo en un modo de transferencia por corto circuito, utilizando un electrodo ER70S-6 y un gas 98%Ar-2%CO2. Se encontro que, manteniendo el voltaje constante, la corriente de soldadura se incremento de manera proporcional (aproximadamente lineal) a la velocidad de alimentacion de alambre e inversamente proporcional a la extension del electrodo. Se compararon las curvas construidas con las disponibles en la literatura y se encontro un desfase de aproximadamente 20 A respecto a la curva resultante para una distancia tubo de contacto-trabajo de 15 mm. Se determino indirectamente la extension del electrodo a partir de la estimacion de las longitudes de arco fotografiadas durante los ensayos.

- by Santiago Aristizábal
- •
- Modeling, Regression Analysis, GMAW, Weld
- by C. Meola
- •
- Nondestructive Evaluation, Collage, Laser Welding, Nondestructive testing
- by Rian Dippenaar
- •
- Atmospheric Science, Arc, Contamination, Weld

It is a trend to use high-strength steels in the automobile industry because of their good formability, weldability, and high strength—volume ratio. In order to achieve quality control, it is necessary to monitor the welding process online. In this paper, acoustic signals generated during the laser welding process of high-strength steel DP980 were recorded and analysed. A microphone was used to acquire the acoustic signals. A spectral subtraction method was used to reduce the noise in the acoustic signals, and a Welch—Bartlett power spectrum density estimation method was used to analyse the frequency characteristics of the acoustic signals. The results indicate that good welds with full penetration (FP) could be clearly distinguished from bad welds with partial penetration (PP). An algorithm based on the different sound pressures between FP and PP was developed to identify the penetration state in the time domain. Another algorithm based on the different frequency characteristics fr...

- by Radovan Kovacevic
- •
- Engineering, Mechanical Engineering, Signal Processing, Modeling
- by Amlan Kar
- •
- Materials Engineering, Mechanical Engineering, Materials, Friction Welding
- by Kuen Ting
- •
- Stress corrosion cracking, Fatigue crack growth, Stainless Steel, PIPE
- by Chaowalit Limmaneevichitr
- •
- Convection, Welding, Electron beam welding, Weld
- by Martin Murray
- •
- Weld
- by Yannick Vincent
- •
- Mechanical Engineering, Applied Mathematics, Microstructure, Modeling
- by Patrizia Sforza
- •
- Engineering, Infrared, Infrared Radiation, Weld

Las fundiciones presentan poca soldabilidad, sin embargo, bajo ciertos cuidados, estos materiales pueden ser soldados y recuperados siguiendo procedimientos rigurosos y seleccionando electrodos de baja entrada de calor para aumentar la... more

- by Dairo Hernán Mesa Grajales
- •
- Recovery, Weldability, Weld, Heat Treatments
- by Chaowalit Limmaneevichitr
- •
- Convection, Visualization, Imaging, Laser Welding

Hundreds of kilometers of pipeline, especially the elbows and welded joints in nuclear power plants (NPPs), are susceptible to aging and other types of damage. Therefore, the condition of a piping system requires regular inspection. We propose an automatic damage visualization technique using a laser ultrasonic scanning system and an ultrasonic wave propagation imaging (UWPI) method for the regular inspection process. Ultrasonic wave propagation movies (UWPMs) in thick and complex NPP pipes could be successfully visualized in a straight pipe with a crack, a welded pipe with multiple open and inner cracks at the welds, and an elbow pipe with wall thinning. A UWPM with ultrasonic time information could enable the discrimination of damage-induced wavefields from the wavefield not related to damage by providing the appearance time, source location, wavefront curvature, and propagation direction of the damage-induced wavefield. For the specimens tested, a 1 mm long crack in a 9 mm thick pipe could be localized regardless of the relative orientation of a sensor to the crack direction; 4 mm long 1.5 mm deep inner crack in a 4 mm thick welding bead could be detected despite the presence of the welding bead; wall thinning with gradual property variations could also be detected. In addition, since this method did not require laser focusing or reference data from the undamaged condition, and allows a large laser beam incident angle, it was very advantageous for the automatic scanning of the curved pipe surfaces. This study demonstrated that the proposed laser ultrasonic system equipped with the UWPI method is a useful inspection tool for NPP piping system management.

- by Chen Ciang Chia
- •
- System Management, Welding, Reference Data, Wave propagation
- by Fabiana Nascimento
- •
- Nitriding, Weld
- by Thomas Bieler
- •
- Materials Engineering, Condensed Matter Physics, Microstructure, Creep

We construct a conformally invariant random family of closed curves in the plane by welding of random homeomorphisms of the unit circle given in terms of the exponential of Gaussian Free Field. We conjecture that our curves are locally... more

- by Antti Kupiainen
- •
- Mathematics, Physics, Pure Mathematics, Welding
- by Glenn Daehn
- •
- Materials Engineering, Mechanical Engineering, Materials Science, Microstructure
- by Christoph Markmann
- •
- Physics, Knowledge, Laser Welding, Geometry

A new simple asymptotic mistuning model, which constitutes an extension of the well known fundamental mistuning model for groups of modes belonging to a modal family exhibiting a large variation of the tuned vibration characteristics, is used to analyze the effect of mistuning on the stability properties of aerodynamically unstable rotors. The model assumes that both the aerodynamics and the structural dynamics of the assembly are linear, and retains the first-order terms of a fully consistent asymptotic expansion of the tuned system where the small parameter is the blade mistuning. The simplicity of the model allows the optimization of the blade mistuning pattern to achieve maximum rotor stability. The results of the application of this technique to realistic welded-in-pair and interlock low-pressure-turbine rotors are also presented.

- by Roque Corral
- •
- Engineering, Mechanical Engineering, Aerospace Engineering, Modeling
- by Juan Alberto Pozo
- •
- Engineering, Heat Transfer, Finite element method, Finite Elements
- by Antti Kupiainen
- •
- Mathematics, Physics, Pure Mathematics, Welding

The measurement of weld penetration using a front-face sensor has been an important issue in welding automation. The fundamental problem is to find a measurable front-face parameter that can adequately represent the weld penetration. In this paper, both the front-face average weld depression depth (a novel weld geometrical parameter) and the weld width are selected as possible representations of full penetration in GTA welding. Two types of sensitivities of front-face weld geometry, with respect to variations in welding conditions and with respect to control variables, are proposed as criteria for determination of promising parameters. Sensitivity calculation of experimental data shows that the front-face weld width is not promising while the average front-face weld depression depth is. This conclusion is also confirmed by a specific experiment and statistic models.

- by Jose Luddey Marulanda Arevalo
- •
- Recovery, Weldability, Weld, Heat Treatments
- by Hirofumi Takeda
- •
- Storage system, Air Temperature, Container, Interdisciplinary Engineering
- by marjon kallewaard
- •
- Surgery, Treatment, Complication, Humans
- by Raafat Ibrahim
- •
- Mechanical Engineering, Design, Stress, Neutron Diffraction

Over the past decade, friction stir welding (FSW) has rapidly become an important industrial joining process, particularly in the aluminum industry. Included among the advantages of FSW are such important attributes as improved weld strength and the elimination of cracking and porosity. During the friction stir process, the metal undergoes a tortuous deformation path that is not yet fully understood. The crystallographic texture that evolves during FSW contains sharp spatial gradients that undoubtedly influence the integrity of the weld and surrounding region in subsequent performance. The locally measured textures are discussed in the context of the material flow required to produce such textures, ultimately resulting in an estimate of the flow field present during FSW.

- by Frank Barbaro
- •
- Materials Science, Control, Properties, Zone

As an unsupported structure, a berthing monopile is often expected to work under harsh conditions. Approaching vessels may introduce considerable berthing energy, resulting in substantial tensile stress on the pile. This vessel impact occurs frequently as a primary load over the service life of the berthing monopile. In this situation, the fatigue safety of circumferential butt welds on piles becomes a crucial aspect in monopile design. This paper evaluates linear elastic fracture mechanics (LEFM)-based fatigue reliability for circumferential splice welds on steel monopiles. Studied monopiles are those installed in inland waterways, for which the predominant fatigue loading is vessel berthing. Important factors involved in the fatigue reliability assessment are addressed. A geometry function for determining the range of stress intensity factor is identified, an approximate stress concentration factor for piles under bending moment is mathematically formulated, and the beta distribution is applied to characterize the doubly bound hot-spot stress range caused by operational water-level constraints. A detailed case study is presented for illustrative purposes. This paper provides a practical approach to assessing LEFM-based fatigue reliability for steel berthing monopiles. DOI: 10.1061/(ASCE)WW.1943-5460.0000063. © 2011 American Society of Civil Engineers. CE Database subject headings: Piles; Marine terminals; Welds; Cracking; Fatigue life; Joints; Reliability; Waterways. Author keywords: Steel piles; Marine terminals; Welds; Cracking; Fatigue life; Tube joints; Reliability; Inland waterways.

- by Barbara Lence
- •
- Civil Engineering, Geology, Structural Analysis, Crack propagation
- by Peter Hammersberg
- •
- Six Sigma, Measurement, Information Transfer, Weld
- by Jose Luddey Marulanda Arevalo
- •
- Wear, Tribology, Chromium, Abrasion
- by Lawrence Murr
- •
- Materials Engineering, Mechanical Engineering, Materials, Friction Welding
- by Bryan Poulson
- •
- Materials Engineering, Mechanical Engineering, Civil Engineering, Corrosion Science
- by noritaka yusa
- •
- Signal Processing, Stress corrosion cracking, Numerical Simulation, Eddy Current

ABSTRACT. A transparent pool of NaNO3 (10 mm in diameter) was heated with a defocused CO2 laser beam to simulate Marangoni convection in arc weld pools without a surface-active agent. The flow patterns were revealed clearly by flow visualization with a laser light-cut technique, the surface temperature profiles were measured immediately below the pool surface, and a device for measuring the beam diameter was developed. The observed Marangoni convection was expected to resemble that in welding because the Marangoni ...

- by Chaowalit Limmaneevichitr
- •
- Convection, Visualization, Imaging, Laser Welding
- by Mike Viola
- •
- Physics, Plasma Physics, Welding, Stainless Steel

Residual stress are stresses that remains in an engineering material, especially metallic materials, after the original applied load has been removed. Its measurement will help reveal areas in fabricated materials highly stressed. This paper presents a design of a portable residual stress measuring device based on the magnetic barkhausen noise principle. This was achieved by using two permanent magnets, a pickup coil, amplifier and an analogue to digital converter to create the hardware. The software was designed using LabVIEW 2019. After fabrication, measuring experiments on mild steel materials were conducted and the results obtained from using the device for measurement were compared to simulated values (Simufact.Weld 6.0) CAD software. Comparing its results with that obtained from Simulation showed an R 2 value of 77.47% with a strong correlation of 0.831and a P-value of 0.0071 which was less than the 0.05 alpha level taken. This device can be adopted in weld residual stress measurement by artisans and roadside welders for effective minimization of residual stress and failures associated with it.

- by NIPES JOURNALS
- •
- LabVIEW, Residual Stress, Weld, Magnet
- by Jorge Barrada
- •
- Productivity, Specification, Weld, Short Circuit

By using optical microscope, the microstructures of 5083/6082 friction stir welding (FSW) weld and parent materials were analyzed. Meanwhile, at ambient temperature and in 0.2 mol/L NaHS03 and 0.6 mol/L NaCl solutionby gravimetric test, potentiodynamic polarization curve test, electrochemical impedance spectra (EIS) and scanning electron microscope (SEM) observation, the electrochemical behavior of 5083/6082 friction stir welding weld and parent materials were comparatively investigated by gravimetric test, potentiodynamic polarization curve test, electrochemical impedance spectra (EIS) and scanning electron microscope (SEM) observation. The results indicated that at given processing parameters, the anti-corrosion property of the dissimilar weld was superior to those of the 5083 and 6082 parent materials.

- by Jiayan Ge
- •
- Earth Sciences, Environmental Sciences, Friction Stir Welding, CHEMICAL SCIENCES

ABSTRACT Nano fillers reinforced polymer composites have been widely applied in microsystem technologies. As one popular micro fabrication technology, micro injection molding is playing the key role in manufacturing micro scale parts made of nano thermoplastics composites. As a defect in micro injection molding parts hard to avoid, the weld line causes detrimental mechanical and physical properties, particularly in case of nano filled composites. In this study, the hybrid carbon nanofibers (CNFs)/TiO2 nano particles (1:1) filled polypropylene (PP) was prepared by inner melts mixing process with various weight contents(10, 20, 30 and 35 wt%). Micro tensile samples with weld lines for all composites were formed by micro injection molding process at constant processing conditions. Mechanical properties of micro weld lines were tested by tensile test characterizing method. The results show that comparison with neat PP, the samples with weld lines made of hybrid nano PP composites are showing lower tensile strength and elongation percent, but higher E modulus. As increasing nano filler contents, the tensile strength and elongation of micro weld line samples are decreasing, while the E modulus is improved considerably.

- by Leif Steuernagel
- •
- Materials Science, Carbon, Nanoparticle, Nanotechnology