This paper presents a methodology for predicting the mechanical properties of welded joints by simulating the heat affected zone (HAZ) using COMSOL Multiphysics. The study includes a comparison between simulated microstructures and those produced through a real welding process, concluding that the simulator can effectively determine mechanical properties of welds. The results align with existing literature on the mechanical properties of API 5L X80 steel.

1. Prediction of the Mechanical Properties in Welded Joints
Using Comsol Multiphysics
R. Alécio1*, N. Bouchonneau1, J. Gama2, T. Antonino3, E. Rocha1; J. Sousa1, P. Guimarães3, J. Barbosa1, Y.
Yadava1, R. Ferreira1.
1Universidade Federal de Pernambuco, 2Instituto Federal de Alagoas, 3Instituto Federal de Pernambuco.
*UFPE/CTG/UFPE. Av. Prof. Moraes Rego, 1235 - Cidade Universitária, CEP: 50670-901 Recife – PE.
Introduction: This paper develops a
theoretical-experimental methodology that
enables the reproduction of the conditions
of thermodynamic points of a HAZ,
generating homogeneous microstructure in
a specimen with dimensions normalized to
carry out tests to determine the mechanical
properties of discretized form of different
points of a heat affected zone ( HAZ ).
Computational Methods: The COMSOL
Multiphysics was used to simulate the flow
temperature from the melting of the metal
on the plate with cooling at room
temperature and get the resistance in
various parts of HAZ.
A model of a three-dimensional metal plate
to simulate the heat input through the weld
puddle and cooling at room temperature
with convection and conduction was
generated by simulating the thermical
contribution to analyze the resistance of
several points compared to reported
values through experimental tests.
Symmetry
Convective
Heat Source
Results: To compare the results
produced by the simulator, a real
welding procedure was performed by
MAG process in the studied material,
where the type of transfer will be
mainly influenced by the current
intensity. So the microstructures of the
HAZ of the weld were compared with
the microstructures of the material
produced in the simulator.
Temp. (°C) Grain size (mm) Stress
1100 0,048 443,1
1000 0,028 473,0
900 0,024 518,2
CR 0,016 543,9
Conclusions: The observed results
demonstrate the feasibility of using the
simulator for the discretization of the
points of the HAZ of a welded joint
allowing the mechanical properties to be
determined in a conventional tensile test.
The calculated values, confirm the
definition of the recent literature on API
5L X80 steel on the mechanical
properties.
References:
1. Ginzburg, V. B., Basic Principles of
Modeling in Metallurgical Design of
Fat-Rolled Steel Products. AISE
Annual Convention. Proceedings.
Pittsburgh, (2003)
2. Silva Jr, at all, Simulação das
transformações de fase em pontos da
ZTA de juntas soldadas do aço API
5L X70, VI Congresso Nacional de
Engenharia Mecânica (2010)
Figure 2. 3D model used
Table 1. Results of samples produced
in thermomechanical simulator
Excerpt from the Proceedings of the 2014 COMSOL Conference in Curitiba
Figure 1. Schematic drawing of the three bodies of
evidence produced in thermomechanical simulator
and the material as received