A heat and fluid flow model has been developed to solve the gas tungsten arc (GTA) linear welding problem for austenitic stainless steel. The moving heat source problem associated with the electrode traverse has been simplified into an equivalent two-dimensional (2-D) transient problem. The torch residence time has been calculated from the arc diameter and torch speed. The mathematical formulation considers buoyancy, electromagnetic induction, and surface tension forces. The governing equations have been solved by the finite volume method. The temperature and velocity fields have been determined. The theoretical predictions for weld bead geometry are in good agreement with experimental measurements. © 2008 The Minerals, Metals & Materials Society and ASM International.

T Sundararajan

Department of Mechanical Engineering

Austenitic stainless steel

Austenitic steel

Cavity resonators

Electric welding

electromagnetic induction

Finite volume method

FLUID MECHANICS

Inert gas welding

Numerical analysis

Steel

Steel corrosion

Steel metallurgy

Surface chemistry

Surface tension

Tungsten

Two dimensional

Welding

AUSTENITIC

FLUID-FLOW MODELS

STAINLESS STEELS

SURFACE TENSION FORCES

Stainless steel

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science

A simplified heat and fluid flow model has been used to solve the Gas Tungsten Arc (GTA) linear welding problem for austenitic stainless steel. In this study, an equivalent 2-D (two-dimensional) transient heat and fluid flow model has been used to study the effect of controlled boundary conditions with free bottom surface and with bottom insulation. The governing equations have been solved by a finite volume method. The peak temperature, maximum velocity in the weld pool, weld bead width and depth get reduced when the bottom surface of the stainless steel plate is insulated. Copyright © 2010 Inderscience Enterprises Ltd.

International Journal of Materials and Product Technology

A simplified 2-D model for the linear GTA welding of stainless steel plates

In this work, experimental and numerical investigations of spheres burning in a convective environment have been carried out. In the numerical simulations, transient axi-symmetric Navier-Stokes equations along with species and energy conservation equations are solved using a finite volume technique based on non-orthogonal semi-collocated grids. A global single step reaction involving two reactants, two products and one inert species together with an Arrhenius rate equation has been used to model kinetics. For the sake of comparison, an infinite rate chemistry model has also been attempted. The density of the mixture has been evaluated from ideal gas equation of state. Thermo-physical properties like thermal conductivity and viscosity have been evaluated using the Chapman-Enskog description of binary gas mixtures. Specific heats and species enthalpies have been evaluated using piece-wise polynomials of temperature. The burning of isolated spherical particles in a mixed convective environment at atmospheric pressure has been simulated for various particle sizes, free-stream velocities and ambient temperatures. The numerical predictions have been compared with experimental results obtained using the porous sphere technique and the agreement is found to be good. Correlations have been developed for the critical Reynolds number at which transition from the envelope to wake flame occurs and also for the mass burning rates at sub-critical or super-critical Reynolds number regimes. It is observed that, at higher ambient temperatures, transition to wake flame is delayed to a higher critical Reynolds number value. The infinite rate chemistry model predicts flame shapes and mass burning rates with reasonable accuracy in the sub-critical Reynolds number regime, but it fails to predict transition to wake flame shape. For analyzing transition phenomena, a finite rate chemistry model is required. © 2005 Elsevier Ltd. All rights reserved.

International Journal of Heat and Mass Transfer

Flame shapes and burning rates of spherical fuel particles in a mixed convective environment

Computational Materials Science

Modeling and finite element analysis on GTAW arc and weld pool

Heat transfer and fluid flow in a partially or fully penetrated weld pool in gas tungsten arc welding

Welding is a reliable, cost effective, and efficient metal joining process. Manual metal arc welding (MMAW) is a widely used welding process in industry and multipass welding is very frequently used in the MMA W process. The temperature distribution that prevails during multipass welding affects the material microstructure and hardness of the regions near the weld, and the residual stresses that will be present in the material after cooling to room temperature. These changes will consequently affect the performance of the welded joint. In the present work, a computer model based on the control volume method has been developed to predict the temperature distribution during multipass welding of plates using the MMAW process. To validate the computer model, the temperature distribution was measured experimentally in a 12 mm thickness stainless steel weld pad during multipass welding. The welding parameters were used as input data for the computer model. The computer predictions and the experimentally measured temperature distributions agree well.

Science and Technology of Welding and Joining

Numerical modelling of temperature distribution during multipass welding of plates

Metallurgical and Materials Transactions B

Modeling macro-and microstructures of Gas-Metal-Arc Welded HSLA-100 steel

Modeling of linear gas tungsten arc welding of stainless steel

Journal	Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
ISSN	10735615
Open Access	No