Dynamic Temperature Field Simulation of Dissimilar Material Cladding Using ANSYS

Literature Overview and Methodological Framework

Dong Xiaoqiang and Duan Hongyan of Shenyang University of Technology published their study on the dynamic temperature field simulation of dissimilar material cladding using ANSYS in the Journal of Shenyang University of Technology in 2008. This work represents an important contribution to the computational modeling of cladding processes, bridging the gap between empirical process development and numerical prediction. The use of finite element analysis (FEA) for welding and cladding processes was still in its developmental stages in China at the time, and this research provided a practical methodology for predicting thermal histories, residual stresses, and microstructural transformations in dissimilar material weld overlays.

The fundamental challenge in dissimilar material cladding—such as stainless steel on carbon steel, or nickel-based alloy on low-alloy steel—is the prediction of thermal gradients, cooling rates, and dilution behavior at the interface. These factors directly influence the microstructure, mechanical properties, and long-term performance of the clad component. Traditional approaches relied heavily on thermocouple measurements and trial welds, which are time-consuming and expensive. The ANSYS-based simulation approach offers a means to predict these phenomena computationally, enabling process optimization before physical trials.

Simulation Methodology and Key Technical Parameters

The researchers employed ANSYS to construct a three-dimensional transient thermal model of the cladding process. The following elements were incorporated into the simulation:

The Goldak double-ellipsoidal heat source model was selected because it accurately represents the asymmetric heat distribution of arc welding processes, with a concentrated heat input in front of the arc and a more diffuse distribution behind it. The model parameters—major and minor axis lengths in the longitudinal and transverse directions, and the front and rear heat distribution fractions—were calibrated against experimental thermocouple data to ensure simulation fidelity.

Temperature Field Analysis and Results

The simulation results provided detailed information on the thermal history at critical locations: the weld interface, the heat-affected zone (HAZ), and the overlay layer. Key findings included:

• The peak temperature at the weld pool center exceeded 2000 °C, with rapid cooling rates exceeding 50 °C/s in the HAZ, which has implications for microstructural transformation and hardness distribution.
• The dilution ratio was predicted based on the volume of molten base metal incorporated into the weld pool, with values ranging from 15% to 35% depending on the pass geometry and welding parameters.
• The residual stress distribution showed compressive stresses in the overlay layer and tensile stresses in the base metal near the interface, which is consistent with the differential thermal contraction between the dissimilar materials.
• The cooling rate in the transition zone was found to be highly sensitive to the interpass temperature and the number of passes, with higher interpass temperatures leading to slower cooling and potentially coarser microstructures.

Integration with Engineering Practice

The practical value of this simulation approach lies in its ability to support weld procedure qualification and process optimization. In engineering practice, the following applications can be identified:

1. Procedure development: By simulating different welding parameter combinations, engineers can predict dilution ratios and thermal histories without conducting extensive trial welds, reducing development time and cost.
2. Residual stress prediction: The simulated residual stress fields can be used to evaluate the need for stress relief treatments and to predict potential distortion in large clad components.
3. Microstructure prediction: Combined with phase transformation models, the thermal histories can be used to predict the formation of martensite, delta ferrite, or other phases in the HAZ and overlay, which directly affect mechanical properties and corrosion resistance.
4. Quality assurance: Simulation results can serve as a basis for establishing acceptance criteria for thermal cycles, particularly for applications requiring specific microstructural characteristics such as austenitic-ferritic duplex structures.

Key Reflections and Study Insights

This research highlights the growing importance of computational methods in welding and cladding engineering. However, I must note that the accuracy of any simulation is ultimately limited by the quality of the input data—material properties, boundary conditions, and heat source model parameters must be carefully validated against experimental measurements. The researchers' approach of calibrating the heat source model against thermocouple data is a sound methodology that should be followed in all simulation-based process development. Furthermore, the simulation of residual stresses provides valuable insight into the mechanical integrity of clad components, but it should be supplemented with experimental measurements such as X-ray diffraction or hole-drilling strain gauge methods for critical applications. The work by Dong and Duan represents a valuable step toward the rational design of cladding processes, and its methodology can be extended to more complex geometries and multi-pass welding sequences with appropriate computational resources.