A NEW HEAT SOURCE MODEL FOR KEYHOLE MODE LASER WELDING

2021 ◽  
pp. 1-14
Author(s):  
Samuel Lorin ◽  
Julia Madrid ◽  
Rikard Söderberg ◽  
Kristina Wärmefjord
Keyword(s):  
Heat Source ◽  
Laser Welding ◽  
Heat Input ◽  
Source Model ◽  
Fluid Simulation ◽  
Heat Sources ◽  
Heat Source Model ◽  
Mode Laser ◽  
Standard Heat

Abstract Laser welding is a common technique for joining metals in many manufacturing industries. Due to the heat input and the resulting melting and solidification, the parts deform causing residual distortion and residual stresses. To assure the geometrical and functional quality of the product, Computational Welding Mechanics (CWM) is often employed in the design phase to predict the outcome of different design proposals. Furthermore, CWM can be used to design the welding process with the objective of assuring the quality of the weld. However, welding is a complex multi-physical process and in a design process it is typically not feasible, for example, to employ fluid simulation of the weld pool in order to predict deformation, especially if a set of design proposals is under investigation. Instead, what is used is a heat source that emulates the heat input from the melt pool. However, standard heat sources are typically not flexible enough to capture the fusion zone for deep keyhole mode laser welding. In this paper, a new heat source model for keyhole mode laser welding is presented. In an industrial case study, a number of bead on plate welds have been employed to compare standard weld heat sources and develop the new heat source model. The proposed heat source is based on a combination of standard heat sources. From the study, it was concluded that the standard heat sources could not predict the observed melted zone for certain industrial application while the new heat source was able to do so.

scholarly journals Thermal Analysis Simulation for Laser Butt Welding of Inconel625 Using FEA

2018 ◽  
Vol 7 (4.10) ◽  
pp. 85 ◽  
Author(s):  
Harinadh Vemanaboina ◽  
G. Edison ◽  
Suresh Akella ◽  
Ramesh Kumar Buddu
Keyword(s):  
Heat Source ◽  
Residual Stresses ◽  
Laser Beam ◽  
Laser Welding ◽  
Process Parameters ◽  
Heat Input ◽  
Laser Beam Welding ◽  
Source Model ◽  
Heat Source Model ◽  
Welding Processes

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.  

scholarly journals A Study on Welding Deformation in Fiber Laser Welding of 9% Nickel Steel through Finite Element Analysis Part I: Implementation of Welding Heat Source Model

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2188
Author(s):  
Changmin Pyo ◽  
Jaewoong Kim ◽  
Du-Song Kim
Keyword(s):  
Natural Gas ◽  
Heat Source ◽  
Laser Welding ◽  
Fiber Laser ◽  
Source Model ◽  
Heat Transfer Analysis ◽  
Welding Deformation ◽  
Nickel Steel ◽  
Fiber Laser Welding ◽  
Heat Source Model

Due to various environmental regulations, the demand for natural gas, i.e., a clean energy, is expected to increase continuously. In terms of efficient storage and transportation of natural gas, liquefied natural gas has an advantageous volume of 1/600 compared to natural gas, but the materials that can be used at a cryogenic temperature of −163 °C are limited. A 9% nickel steel is a material recommended by IMO through IGC. It has excellent mechanical properties compared to other cryogenic materials, but its use has been limited due to its disadvantages in arc welding. Therefore, the main topic of this study is the automatic welding of 9% nickel steel using fiber laser and its purpose is to predict the welding deformation during fiber laser welding. First, an investigation was conducted to find the fiber laser welding heat source. A model that can cover all the models in prior studies such as curve, exponential, conical, conical-conical combination, and conical-cylinder combination models was proposed and the heat source model was constructed in a multi-layer format. Heat transfer analysis was performed using the ratio of a heat source radius and heat energy of each layer as a variable and the pass or failure of a heat source was determined by comparing the analysis results to the experimental results. By changing the variables in conjunction with the optimization algorithm, the main parameters of a passed heat source model were verified in a short period of time. In addition, the tendency of parameters according to the welding speed was checked.

scholarly journals Development of a Heat Source Model for Narrow-gap Hot-wire Laser Welding

2013 ◽  
Vol 31 (4) ◽  
pp. 82s-85s ◽  
Author(s):  
Rittichai Phaonaim ◽  
Masayuki Yamamoto ◽  
Kenji Shinozaki ◽  
Motomichi Yamamoto ◽  
Kota Kadoi
Keyword(s):  
Heat Source ◽  
Laser Welding ◽  
Source Model ◽  
Narrow Gap ◽  
Hot Wire ◽  
Heat Source Model

Thermal Aspects of the Split-Beam Laser Welding Concept

1991 ◽  
Vol 113 (2) ◽  
pp. 215-221 ◽  
Author(s):  
Elijah Kannatey-Asibu
Keyword(s):  
Heat Source ◽  
Laser Welding ◽  
Cooling Rate ◽  
Weld Pool ◽  
Heat Input ◽  
Total Heat ◽  
Source Process ◽  
Heat Sources ◽  
Single Source ◽  
Beam Laser

The high cooling rates normally encountered in the application of high intensity welding processes such as laser beam welding is often detrimental to the weldment, especially for high hardenability steels. To minimize this effect, the split-beam laser welding concept is proposed and analyzed. The analysis shows that even when the intensity of the single heat source is the same as the intensity of each of the dual heat sources, the resulting cooling rate at any specific temperature is lower for the dual source process than the single source process. For example, for mild steel, the cooling rate at a point 25 mm behind the heat source (where the temperature is 1364°C) was determined to be 382°C/s for the single source system, while that for a point 40 mm behind the major source (where the temperature is 1377°C) was determined to be 206°C/s for the dual heat source system. When the heat inputs for the dual system are reduced such that the total heat input is equal to that of the single source system, the resulting temperature rise is lower at all points of the weldment for the dual system. That also means a smaller weld pool size and heat affected zone. To maintain the same weld pool size and penetration as for the single heat source system then requires an increased total heat input for the dual heat source system, with the additional input depending on the spacing between the two heat sources.

Comparison on welding mode characteristics of arc heat source for heat input control in hybrid welding of aluminum alloy

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540016
Author(s):  
Moo-Keun Song ◽  
Jong-Do Kim ◽  
Jae-Hwan Oh
Keyword(s):  
Experimental Study ◽  
Aluminum Alloy ◽  
Heat Source ◽  
Laser Welding ◽  
Heat Input ◽  
Heat Sources ◽  
Hybrid Welding ◽  
Input Control ◽  
Mode Characteristics ◽  
Pulsed Arc

Presently in shipbuilding, transportation and aerospace industries, the potential to apply welding using laser and laser-arc hybrid heat sources is widely under research. This study has the purpose of comparing the weldability depending on the arc mode by varying the welding modes of arc heat sources in applying laser-arc hybrid welding to aluminum alloy and of implementing efficient hybrid welding while controlling heat input. In the experimental study, we found that hybrid welding using CMT mode produced deeper penetration and sounder bead surface than those characteristics produced during only laser welding, with less heat input compared to that required in pulsed arc mode.

scholarly journals Research on Heat Source Model and Weld Profile for Fiber Laser Welding of A304 Stainless Steel Thin Sheet

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Peizhi Li ◽  
Yu Fan ◽  
Chonghao Zhang ◽  
Zhiyuan Zhu ◽  
Wenteng Tian ◽  
...  
Keyword(s):  
Heat Source ◽  
Laser Welding ◽  
Fiber Laser ◽  
Source Model ◽  
Depth Of Penetration ◽  
Fiber Laser Welding ◽  
Heat Source Model ◽  
Bead Width ◽  
Weld Profile ◽  
Simulation Results

A heat source model is the key issue for laser welding simulation. The Gaussian heat source model is not suitable to match the actual laser weld profile accurately. Furthermore, fiber lasers are widely recognized to result in good-quality laser beam output, a narrower weld zone, less distortion, and high process efficiency, compared with other types of lasers (such as CO2, Nd : YAG, and diode lasers). At present, there are few heat source models for fiber laser welding. Most of researchers evaluate the weld profile only by the bead width and depth of penetration, which is not suitable for the laser keyhole welding nail-like profile. This paper reports an experimental study and FEA simulation of fiber laser butt welding on 1 mm thick A304 stainless steel. A new heat source model (cylindrical and cylindrical) is established to match the actual weld profile using Marc and Fortran software. Four bead geometry parameters (penetration depth, bead width, waist width, and depth of the waist) are used to compare between the experimental and simulation results. The results show that the heat source model of cylindrical and cylindrical can match the actual shape of the fiber laser welding feasibly. The error range of the penetration depth, bead width, waist width, and depth of the waist between experimental and simulation results is about 4.1 ± 1.6%, 2.9 ± 2.0%, 13.6 ± 7.4/%, and 18.3 ± 8.0%, respectively. In addition, it is found that the depth of penetration is more sensitive to laser power rather than bead width, waist width, and depth of the waist. Welding speed has a similar influence on the depth of penetration, weld width, waist width, and depth of the waist.

Numerical and Experimental Study of Temperature Field for Double Electrode Gas Metal Arc Welding

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Yu Shi ◽  
Rihong Han ◽  
Jiankang Huang ◽  
Shao Yan
Keyword(s):  
Temperature Field ◽  
Heat Source ◽  
Base Metal ◽  
Heat Input ◽  
Gas Metal Arc Welding ◽  
Source Model ◽  
Welding Parameters ◽  
Heat Source Model ◽  
Double Electrode ◽  
Simulation Results

Based on the features of double electrode gas metal arc welding (DE-GMAW), a new hybrid heat-source model for DE-GMAW was proposed. Using this heat-source model, the temperature fields of DE-GMAW with different welding parameters were simulated. According to the simulation results with different welding parameters, the influence of welding parameters to the heat input to base metal in DE-GMAW were analyzed. To verify the rationality of the hybrid heat-source model of DE-GMAW, the simulation results of the temperature field were compared with the experimental results with same welding parameters. The research results indicate that under the same total current, the heat input to base metal decrease gradually with the increase of by-pass current. In addition, the closer to the welding line from the measured point the greater decrease rate of the heat input to base metal. By the study and comparison of the thermal cycle curve of measured points, the simulation results were in good agreement with the experimental results. These results indicate that the calculated temperature field is accurate and the hybrid heat-source model is rational.

Heat Source Model of Lap Laser Welding of Stainless Steel Vehicle

2011 ◽  
Vol 121-126 ◽  
pp. 3347-3351 ◽  
Author(s):  
Hong Xiao Wang ◽  
Chun Sheng Wang ◽  
Chun Yuan Shi ◽  
Zhi Yi Huang
Keyword(s):  
Stainless Steel ◽  
Heat Source ◽  
Laser Welding ◽  
Process Parameters ◽  
Production Efficiency ◽  
Three Dimensional ◽  
Source Model ◽  
Heat Source Model ◽  
Element Analysis ◽  
Welding Temperature

Resistance spot welding (RSW) is being taken place by partial lap laser welding for the poor surface quality and bad airtight due to the pressure of electrodes. The shape of partial lap laser welding is similar to the vase. When the penetration of the joint is in a certain range, there is no welding trace on the outer surface. Laser welding temperature field numerical analysis based on Abaqus finite element analysis software is committed to obtain a suitable range of process parameters to improve production efficiency and automation by determining the joint penetration. To master the laser lap welding of stainless steel weld penetration state, the combination of three-dimensional positive cone + three-dimensional inverted cone + half-ellipsoid heat source model was established simulating stainless steel lap laser weld pool shape and forecasting the range of process parameters .

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