Thermal and Residual Stress Distributions in Inconel 625 Butt-Welded Plates: Simulation and Experimental Validation

Thermal and residual stress distributions induced by the gas tungsten arc welding (GTAW) process on Inconel 625 were studied using numerical simulation and experiments. A multi-pass welding model was developed that uses a volumetric heat source. Thermomechanical analysis is carried out to assess the Thermal and residual stress distributions. Experiments were carried out with 5 mm thick Inconel 625 plates. X-ray diffraction techniques were used to measure residual stresses, and IR thermometry was employed to capture the temperature values on the welded joints. Simulations were performed with ANSYS numerical code, and a close agreement was found between the predicted and experimentally measured residual stress. Thermal measurements were collected pass by pass from the analysis, and the agreement was 9.08%. The agreement between the measured and analysed residual stress was 11%

SIMULATION OF HYBRID LASER-TIG WELDING PROCESS USING FEA

Hybrid welding technology has wide advantages in welding to improve speed, weldability of special materials, increasing depth of weld. Less defects of the weld, less bead widths, less temperature, less distortion and less residual stresses are seen. In this study, a three-dimensional Finite Element Model is developed for butt joints for SS316L. The heat flux models of double ellipsoidal surface heat flux of TIG process and lateral heat to the thickness face of laser process are used to model combined TIG and Laser welding processes for simulating. Total heat is distributed as surface heat flux and lateral heat flux, which can be incorporated in modelling with the proportion for Hybrid laser-TIG welding process. The transient thermal analysis, with thermally dependent properties, is performed to achieve the temperature distribution during the process; later, it is used to apply for the mechanical analysis of distortion and stresses. Uniform distortion along the weld with edge deformations is found. Residual stresses will maintain structural integrity with minimum 1.3 factor of safety. In this study, to save computing time, symmetric conditions were used for analyzing only half the product

Residual Stress Distribution in Selective Laser Melting of SS316L Parts

Additive manufacturing is one of the fastest-growing fields in materials engineering. This is because there is a new trend for custom, high-precision, and on-demand manufacturing. The undesired residual stress induced in the components during layer-by-layer melting and solidification of the metal powder is an important issue related to the selective laser melting (SLM) process that needs to be studied deeply. These stresses may impair mechanical performance and potentially result in premature failure. As a result, a thorough knowledge of residual stress is crucial for improved component dependability. By keeping constant process parameters, samples were produced with a difference in the scanning method. Results indicate that the defect-free parts are manufactured in all the four patterns used, and the self-balanced residual stresses are within the safe limits of yield strength

Effect of Heat Input on Distortions and Residual Stresses Induced by Gas Tungsten Arc Welding in SS 316L to INCONEL625 Multipass Dissimilar Welded Joints

In the present study, distortion and residual stresses in the multipass welded joint were analyzed with respect to heat input. The welded joint was produced using the gas tungsten arc welding (GTAW) process with dissimilar Ni-based filler of ERNiCrMo-3. This dissimilar joint is essential in power generating nuclear and thermal plants operating at elevated temperatures. The distortion and residual stress measurements were taken using the Vernier height gauge and XRD method. To evaluate the mechanical properties, tensile testing was carried out at room temperature. The welded joint qualified the tensile test with an average value of 593 MPa. In the weld metal, a significant variation of residual stresses is measured on the top surface of the weldment along with the thickness with peak magnitude of 145 MPa to 180 MPa at the fusion zone

Optimisation process parameters for Multipass GTAW dissimilar materials of SS316L to INCONEL625

This study aims to learn how welds' bead width and tensile strength have changed throughout time. The research welded the multipass dissimilar of nickel-based superalloy Inconel 625 and stainless steel 316L using CCGTAW and ERNiCrMo-3. This experimental cycle made use of the L9 orthogonal array. Analysis of Variance (ANOVA) is used to zero in on and identify the most critical variables. Weld quality is evaluated throughout production using a non-destructive method. Weld quality and tensile strength were tested in Universal testing Machine X-Ray Radiography. Welding current and root gap were shown to be significant factors

Distortion control in CO2 Laser Beam dissimilar welds of SS316L to INCONEL625 plates

The paper attempts to join similar and dissimilar joints by employing CO2 laser beam welding. The SS316L and INCONEL625 plates of 5mm thick plates are used. The L4 orthogonal array was chosen for the experimentation. Three parameters are chosen in two levels, and four trials are optimized. Analysis of Variance (ANOVA) is used to optimize and determine the most critical parameters. The weldments have undergone visual, X-ray radiography, and macrostructure examination to verify the quality of the weldments verified with full penetration. Distortion in dissimilar weldments may be measured using a vernier height gauge. Simple inspection methods, No-way ANOVA, Linear Figures, and ANOVA were used, and two parameters were identified with 99% criticality. ANOVA shows 95% significance for distortion with welding speed at 51.9%, welding current at 13%, and shielding Flow rate at 12.3% contribution. The welding speed and laser power are significant, while shielding gas is not a critical parameter but essential for the quality of the joint

Mechanical and Metallurgical Properties of CO2 Laser Beam INCONEL 625 Welded Joints

In the frame of the circular economy, welding of Ni-based superalloys has gained increasing importance when applied, for instance, to repairing highly expensive components widely used in strategical sectors, such as the defense and aerospace industries. However, correct process parameters avoiding metallurgical defects and premature failures need to be known. To reach this goal, Inconel 625 butt-welded joints were produced by CO2 laser beam welding and different combinations of process parameters. The experimental investigation was carried out with three parameters in two levels with an L4 orthogonal array. Laser power, welding speed, and shielding gas flow rate were varied, and the results were reported in terms of mechanical properties, such as microhardness, tensile strength, distortion, residual stress, and weld bead geometry, and metallurgy. At a lower welding speed of 1 m/min, the full penetration was observed for 3.0 kW and 3.3 kW laser powers. However, sound welds (porosity-free) were produced with a laser power of 3.3 kW. Overall, the obtained full-penetration specimens showed a tensile strength comparable with that of the parent material with residual stresses and distortions increasing with the increase in heat input