scholarly journals THE IMPACT OF SELECTED PROCESSES AND TECHNOLOGICAL PARAMETERS ON THE GEOMETRY OF THE WELD POOL WHEN WELDING IN SHIELS GAS ATMOSPHERE

2017 ◽  
Vol 57 (2) ◽  
pp. 78
Author(s):  
Josef Bradáč ◽  
Jaromír Moravec
Keyword(s):  
Numerical Model ◽  
Weld Pool ◽  
Welding Process ◽  
Welding Current ◽  
Technological Parameters ◽  
Preheating Temperature ◽  
Gas Atmosphere ◽  
Simulation Results ◽  
Input Variables ◽  
The Impact

This paper is focused on welding with a consumable electrode in a gas shield atmosphere and its main aim is to show the influence of selected processes and technological parameters on the geometry of the weld pool in terms of theoretical and experimental views. For this purpose, the parametric areas defined by the change of the welding current and welding rate were determined. Apart from the influence of these parametric areas, the influence of other technological input variables, including the wire diameter and preheating temperature, was also studied. The experimentally obtained geometric data of the weld pool can be used for technological welding procedures WPS and especially for simulation calculations to obtain a more accurate numerical model of the heat source. This makes it possible to get accurate simulation results and to better understand the impact of other variables that influence the welding process. This all helps to the optimization of the welding process for several applications.

scholarly journals Study the Effect of Welding Heat Input on the Microstructure, Hardness, and Impact Toughness of AISI 1015 Steel

2018 ◽  
Vol 14 (1) ◽  
pp. 118-127 ◽  
Author(s):  
Emad Kh. Hamd ◽  
Abbas Sh. Alwan ◽  
Ihsan Khalaf Irthiea
Keyword(s):  
Corrosion Rate ◽  
Weld Joint ◽  
Heat Input ◽  
Plate Thickness ◽  
Welding Process ◽  
Welding Current ◽  
Low Carbon ◽  
Mig Welding ◽  
The Impact ◽  
Weld Heat

In the present study, MIG welding is carried out on low carbon steel type (AISI 1015) by using electrode ER308L of 1.5mm diameter with direct current straight polarity (DCSP). The joint geometry is of a single V-butt joint with one pass welding stroke for different plate thicknesses of 6, 8, and 10 mm. In welding experiments, AISI 1015 plates with dimensions of 200×100mm and edge angle of 60o from both sides are utilized. In this work, three main parameters related to MIG welding process are investigated, which are welding current, welding speed, heat input and plate thickness, and to achieve that three groups of plates are employed each one consists of three plates. The results indicate that increasing the weld heat input (through changing the current and voltage) leads to an increase in widmanstatten ferrite (WF), acicular ferrite (AF) and polygonal ferrite (PF) in FZ region, and a reduction in grain size. It is observed that the micro-hardness of welded AISI 1015 plate increases as the weld heat input decreases. As well as increasing the weld heat input results in an increase in the width of WM and HAZ and a reduction in the impact energy of the weld joint of AISI 1015 at WM region. Also, it is noted the corrosion rate of weld joint increases with increase of Icorr due to increasing in welding current (heat input), corrosion rate increased up to (0.126µm/yr.) with increasing of heat input up to (1.27 KJ/mm).  

The Impact of Adscititious Longitudinal Magnetic Field on CO2 Welding Process

2012 ◽  
Vol 538-541 ◽  
pp. 1447-1450 ◽  
Author(s):  
Shu Yuan Jiang ◽  
Xiao Wei Wang ◽  
Huan Ming Chen ◽  
Pin Liu
Keyword(s):  
Magnetic Field ◽  
High Speed ◽  
Longitudinal Magnetic Field ◽  
Short Circuit ◽  
Welding Process ◽  
Welding Current ◽  
High Speed Photography ◽  
Current Decay ◽  
Co2 Welding ◽  
The Impact

Aiming at the welding arc can act with the magnetic field, has electrical quasi-neutral and electrical conductivity. This paper introduced an adscititious longitudinal magnetic field to control the CO2 welding process and used the Hanover Welding Quality Analyzer to acquire the real-time welding signal. Meanwhile, the short circuit behavior of CO2 welding under the adscititious longitudinal magnetic field, was monitored with the High-speed Photography System. The results show that when the excitation current in an optimal range, the welding current decay and the frequency of short circuit transition is uniform and faster, smaller droplet size and the welding process is more stability than welding without adscititious magnetic field.

Effect of Process Parameters on Wavy Interfacial Morphology During Magnetic Pulse Welding

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Shunyi Zhang ◽  
Joern Lueg-Althoff ◽  
Marlon Hahn ◽  
A. Erman Tekkaya ◽  
Brad Kinsey
Keyword(s):  
Numerical Model ◽  
Impact Velocity ◽  
Thermal Analyses ◽  
Welding Process ◽  
Thick Target ◽  
Magnetic Pulse ◽  
Magnetic Pulse Welding ◽  
Interfacial Morphology ◽  
Pulse Welding ◽  
The Impact

Abstract Magnetic pulse welding (MPW) is a solid-state welding process that bonds similar and dissimilar metals using a high velocity collision. In this paper, effects of impact velocity, target tube thickness, and mandrel inclusion on the interfacial morphology were investigated through the welding of tubular parts, Al6060T4 (flyer) to Cu-ETP (target), by electromagnetic compression. The hypothesis tested in this research is that a “well-supported target,” i.e., either a thick target or the support of a mandrel, allows for vortices to be created at the interface during MPW provided that the impact velocity is sufficient. The mandrel used in the experiments was polyurethane with a Shore hardness of 92A, which was pre-stressed via a washer and nut. The impact velocity was measured via photon Doppler velocimetry (PDV) and used for the setup of numerical simulations. A 2D axisymmetric numerical model was implemented in LS-DYNA to predict the interfacial morphology. Thermal analyses in the numerical model were used to predict the local melting locations and compared with experimental observations. Both experimental and numerical results showed that the interfacial wavelength increased with an increase in the impact velocity and target thickness. Similarly, a thin target with mandrel support also caused an increase in the wavelength. Vortices were only generated with appropriate impact velocities and well-supported targets, i.e., again either a thick target or the support of a mandrel.

Numerical Dynamic Analysis of Moving GTA Weld Pool

1998 ◽  
Vol 120 (1) ◽  
pp. 173-178 ◽  
Author(s):  
Z. N. Cao ◽  
Y. M. Zhang ◽  
R. Kovacevic
Keyword(s):  
Weld Pool ◽  
Plate Thickness ◽  
Three Dimensional ◽  
Calculated Data ◽  
Welding Process ◽  
Welding Current ◽  
Three Dimensional Model ◽  
Full Penetration ◽  
Weld Pools ◽  
Describe Heat Transfer

A three dimensional model with a moving heat source is developed to describe heat transfer and fluid flow in transient weld pools. Full penetration and free top and bottom surfaces are incorporated in the model in order to simulate the welding process more practically. The influence of plate thickness and welding current on the dynamics of weld pools is analyzed using calculated data. It is shown that when the workpiece is nearly penetrated, the depth of weld pool increases quickly. Also, the elevation of the top surface decreases quickly once the full penetration status is established.

scholarly journals The impact of heat input on the mechanical properties and microstructure of High Strength Low Alloy steel welded joint by GMA welding process

2021 ◽  
Vol 9 (3) ◽  
pp. 299-310 ◽  
Author(s):  
Saadat Ali Rizvi ◽  
Rajnish Singh ◽  
Saurabh Kumar Gupta
Keyword(s):  
Mechanical Properties ◽  
Alloy Steel ◽  
Heat Input ◽  
Gma Welding ◽  
Hsla Steel ◽  
Welding Process ◽  
Welding Current ◽  
High Strength ◽  
Low Alloy Steel ◽  
The Impact

The basic aim of this study was to find a relationship between heat input and mechanical properties of high strength low alloy steel (HSLA) welded joints and also elaborate its effect on microstructure. The combined effect of welding current, voltage and speed i.e. Heat Input on mechanical properties of High Strength Low Alloy Steel (ASTM A242 type-II) weldments have been studied in the present work. HSLA steel work pieces were welded by Gas metal arc welding (GMAW) process under varying welding current, arc voltage, and welding speed. Total nine samples were prepared at different heat input level i.e. 1.872 kJ/mm, 1.9333 kJ/mm, 2.0114 kJ/mm, 2.1 kJ/mm, 2.1956 kJ/mm, 2.296 kJ/mm, 2.4 kJ/mm, 2.5067 kJ/mm and 2.6154 kJ/mm It was observed that as heat input increases the ultimate tensile strength and microhardness of weldment decreased while impact strength increased and it was also observed that on increasing the heat input grain size of microstructure tends to coarsening it is only due to decreasing in cooling rate.

scholarly journals Analysis of the Covered Electrode Welding Process Stability on the Basis of Linear Regression Equation

2014 ◽  
Vol 59 (3) ◽  
pp. 905-909
Author(s):  
J. Słania ◽  
B. Ślązak
Keyword(s):  
Linear Regression ◽  
Welding Process ◽  
Welding Current ◽  
Process Stability ◽  
Arc Voltage ◽  
Welding Arc ◽  
Instantaneous Values ◽  
Welding Properties ◽  
The Impact ◽  
Coated Electrodes

Abstract The article presents the process of production of coated electrodes and their welding properties. The factors concerning the welding properties and the currently applied method of assessing are given. The methodology of the testing based on the measuring and recording of instantaneous values of welding current and welding arc voltage is discussed. Algorithm for creation of reference data base of the expert system is shown, aiding the assessment of covered electrodes welding properties. The stability of voltage–current characteristics was discussed. Statistical factors of instantaneous values of welding current and welding arc voltage waveforms used for determining of welding process stability are presented. The results of coated electrodes welding properties are compared. The article presents the results of linear regression as well as the impact of the independent variables on the welding process performance. Finally the conclusions drawn from the research are given.

scholarly journals Evasive Maneuvers in Space Debris Environment and Technological Parameters

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Antônio D. C. Jesus ◽  
Rafael S. Ribeiro ◽  
Alessandro Rossi ◽  
Ernesto Veira Neto
Keyword(s):  
Numerical Model ◽  
Impact Velocity ◽  
Space Debris ◽  
Initial Conditions ◽  
Relative Distance ◽  
Technological Parameters ◽  
Collisional Dynamics ◽  
Relative Dynamics ◽  
The Impact ◽  
Warning Time

We present a study of collisional dynamics between space debris and an operational vehicle in LEO. We adopted an approach based on the relative dynamics between the objects on a collisional course and with a short warning time and established a semianalytical solution for the final trajectories of these objects. Our results show that there are angular ranges in 3D, in addition to the initial conditions, that favor the collisions. These results allowed the investigation of a range of technological parameters for the spacecraft (e.g., fuel reserve) that allow a safe evasive maneuver (e.g., time available for the maneuver). The numerical model was tested for different values of the impact velocity and relative distance between the approaching objects.

scholarly journals The Effect of Technological Parameters on the Formation of Fillet Welds in Two-Electrode Submerged Arc Welding

2021 ◽  
Vol 346 ◽  
pp. 01025
Author(s):  
Mikhail Sholokhov ◽  
Daria Buzorina ◽  
Anton Melnikov ◽  
Andrey Fiveyskii ◽  
Alexey Mosin
Keyword(s):  
Weld Pool ◽  
Lower Boundary ◽  
Welding Process ◽  
Transport Infrastructure ◽  
Technological Parameters ◽  
Metal Solidification ◽  
Bridge Structures ◽  
The One ◽  
Submerged Arc ◽  
The Web

The development of transport infrastructure contributes to an increase in the demand for bridge structures, which leads to the need to increase the productivity of their manufacture. The overall increase in welding productivity is facilitated by an increase in the volume of welds performed in a single pass. It is proposed to use two-electrode welding. Computer analysis of such process has shown that an acceptable fillet weld formation can be ensured by rational parameters of the welding process, including the positioning of the electrodes relative to the weld. The distance between the electrodes should be approximately equal to the required leg size, and the electrodes shall be turned by an angle of 45 ° so that the electrode on the web lags behind the one on the flange, and the axis of this electrode is located at a distance equal to half of the required leg, the tilt angle of the torch should be 30 ° from vertical. With the indicated positioning of the electrodes, an asymmetrical weld pool is formed, the end of which is strongly displaced to the web. The melt runoff from the web to the flange is limited by the lower boundary of the weld pool, consequently, the finishing of the runoff and solidification of the metal is shifted towards the web. This fact improves the formation of weld surface, reducing the meniscus at the web and the influx on the flange. Thus, the decrease of the meniscus at the web and the influx on the flange when the arc is placed on the web can be explained by the asymmetric process of metal solidification, which proceeds predominantly from the flange to the web.

scholarly journals Impact of the Welding Parameters on the Width of the Welding beat in TIG Carbon Steel Welding

2021 ◽  
Vol 10 (3) ◽  
pp. 24-29
Author(s):  
Mohammed S ◽  
Ali A. Majeed ◽  
Sobhi Kheirallah
Keyword(s):  
Carbon Steel ◽  
Steel Plate ◽  
Distance Geometry ◽  
Welding Process ◽  
Welding Current ◽  
Tig Welding ◽  
Inert Gas ◽  
Welding Parameters ◽  
Gtaw Process ◽  
The Impact

Tungsten Inert Gas (TIG) welding is otherwise known as the Gas Tungsten Arc soldering (GTAW) process which when significant levels of weld quality or high precision welding are required, is known to represent an advanced arc welding process. However the impact of the welding factors on this form of welding is important for its welding produced in single-pass welding. In this investigation, the autogenous Tungsten Inert Gas (TIG) welding was performed on a carbon mild steel plate with four parametric welding variables. High and low values of material thickness, welding current, welding speed and filler rod diameter have been measured in order to have an impact on an observable parametric response i.e. welding distance. Geometry of the weld bead has been investigated. An expert statistical software design expert has created a mathematical model, The experimental design is central composite design (CCD) and the sold width is the response measured by the Surface Response Methodology (RSM). It has been shown that the maintenance of a suitable parametric welding factor for a carbon steel plate gives substantial values of welding width.

scholarly journals Effect of Preheating on Martensitic Transformation in the Laser Beam Welded AH36 Steel Joint: A Numerical Study

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 127
Author(s):  
Lei Wang ◽  
He Li ◽  
Yong Huang ◽  
Kehong Wang ◽  
Ming Zhou
Keyword(s):  
Martensitic Transformation ◽  
Numerical Model ◽  
Laser Beam ◽  
Fusion Zone ◽  
Numerical Study ◽  
Martensitic Transformations ◽  
Steel Joint ◽  
Preheating Temperature ◽  
Simulation Results ◽  
Continuous Cooling Transformation Diagram

In this work, the effects of preheating temperatures on martensitic transformations in a laser beam-welded AH36 steel joint were observed using a numerical study. In the same weld, the martensitic contents increased slightly from the upper area, the middle area to the lower area, and simulated martensite contents in the fusion zone were slightly lower than that in the HAZ (Heat Affected Zone). Under different preheating temperatures, simulated martensitic contents decrease with the increase of the preheating temperature. According to the simulated results, the average cooling rate and the CCT (Continuous Cooling Transformation) diagram were drawn to analyze the relationships between preheating temperatures and martensitic transformations. Simulated martensitic contents agreed well with the experimental metallographic microstructures. Moreover, the measured microhardness was reduced with the increasing preheating temperature, and measured microhardness in HAZ was higher than that in the fusion zone. The accuracy of the simulation results was further confirmed. The main significance of this work is to provide a numerical model to design martensitic contents in order to control the performances of the weld, avoiding many tests.

Sign in / Sign up

Export Citation Format

Share Document