Thermal Analysis Simulation for Laser Butt Welding of Inconel625 Using FEA

Harinadh Vemanaboina,Suresh Akella,Ramesh Kumar Buddu,G Edison

doi:10.14419/ijet.v7i4.10.20711

Harinadh Vemanaboina, Suresh Akella + Show 2 more

Open Access

https://doi.org/10.14419/ijet.v7i4.10.20711

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Abstract

Laser welding process is employed in the manufacturing of critical components where the final assembly units necessitate strict tolerances like low distortions and residual stresses. Laser beam welding offers several advantages like low heat input, very narrow heat affected zone, low residual stresses, low distortions and good mechanical joint properties in the weld joints when compared to the conventional techniques like Tungsten Inert Gas Arc welding processes. However, the implementation of laser beam welding holds certain challenges like process parameters optimization, experimental set-up and handling and expensive costs. In order to minimize the complex experimental process, simulation techniques using Finite Element Methods (FEM) are employed in order to estimate the heat input and weld process optimization prior to the experiments. This greatly helps in the optimization and estimation of the incurred stresses and distortions with the adapted weld process with known input weld process parameters. The present work reports the Gaussian heat source model for the laser welding of Inconel 625 Alloy plates. The developed moving heat source model is presented and demonstrated with the thermal profiles in terms of the thermal histogram, temperature profiles in the joint cross sections through welded region, interface across the joints.

Highlights

Precision welding techniques have gained importance in the manufacturing sector where the components need to be joined with tight final joint tolerances like low distortions and low heat affected zone and good weld joint properties
Harinadh et al [3,4] had established the simulation of similar and dissimilar materials to estimate the distortions and residual stress by simulations using Finite Element Methods (FEM), the stress results are varied in the component due to the change of the heat input for fabricating of the component based on its material thickness and the type of joint [5]
In laser beam welding process the final welded joint forms fusion zone and heat affected zone will be less compared to an arc welding process

Summary

Introduction

Precision welding techniques have gained importance in the manufacturing sector where the components need to be joined with tight final joint tolerances like low distortions and low heat affected zone and good weld joint properties. The typical applications like in the nuclear sector, heat exchangers pressure vessels, space aircraft have explored the laser and electron beam welding techniques to cater the critical demands. Even though these power beam welding processes are very expensive to deal, the final benefits like narrow heat affected zone, low residual stresses and weld quality with good mechanical joint properties like tensile, toughness and fatigue strength kept them as special manufacturing tools for the requirements. In order to minimize these issue, the alternative way is to predict the weld joints state using simulation by using the boundary conditions of the weld process parameters in terms of heat input and process conditions This provides the 2D and 3D visualization the welded structures using FEM and analysis methods which are widely used. The combined effect of these two heat transfer processes is named as a dynamic boundary condition

Computational Formulation

FEM and Heat Source Model

Results and Discussion

Conclusions