Heat source model for laser beam welding of steel-aluminum lap joints

Evdokimov, A. I.; Springer, Katrin; Doynov, Nikolay; Ossenbrink, Ralf; Michailov, Vesselin

doi:10.1007/s00170-017-0569-6

Cited by 19 publications

(9 citation statements)

References 14 publications

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“…Goldak [5] also describes a cone-shaped, radial normally distributed heat source with linearly increasing heat output over the depth for deep welding processes. Recent studies describe the adaptation of these sources to map complex welding tasks, such as multi-physical [6] or multi-material [7] laser beam welding problems. These recent models deepen the investigations of Xu [8], who proposes a comparable source type with parabolic and linear power distribution functions, so that the heat source function depends on radial varying parameters and which uses an increased calibration effort.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Temperature Fields in Laser Beam Welded Hollow-Cylindrical Cold Crack Samples from High Strength Steel 100Cr6

Wasilewski

Doynov

Ossenbrink

et al. 2021

Preprint

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This work presents a comparative study of thermal conditions that occur during laser beam welding of high strength steel 100Cr6 that often leads to a loss of technological strength and may conditionally produce cold cracks. The results from both experiments and thermal-metallurgical FE-simulations indicate that the type of heat coupling changes significantly when welding with different process parameters, e.g., in the transition between conduction and deep penetration welding. Further, the simulations show that as a result of the high welding speeds and reduced energy per unit length, extremely high heating rates of up to 2x104 K s-1 (set A) resp. 4x105 K s-1 (set B) occur in the material. Both welds thus concern a range of values for which conventional Time-Temperature-Austenitization (TTA) diagrams are not currently defined, so that the material models can only be calibrated using general assumptions. This noted change in energy per unit length and welding speeds causes significantly steep temperature gradients with a slope of approximately 5x103 K mm-1 and strong drops in the heating and cooling rates, particularly in the heat affected zone near the weld metal. This means that even short distances along the length present a staggering difference in relation to the temperature peaks. The temperature cycles also show very different cooling rates for the respective parameter sets, although in both cases they are well below a cooling time t8/5 of one second, so that the phase transformation always leads to the formation of martensite. The results from this study are intended to be used for further detailed experimental and numerical investigation of microstructure, hydrogen distribution, and stress-strain development at different restrain conditions.

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Section: Introductionmentioning

confidence: 99%

Characterization of Temperature Fields in Laser Beam Welded Hollow-Cylindrical Cold Crack Samples from High Strength Steel 100Cr6

Wasilewski

Doynov

Ossenbrink

et al. 2021

Preprint

Self Cite

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“…During discretization of the area where significant heat effect can occur, FE refinement is performed. Welding simulation requires defining heat-source dimensions and heat-energy volume related to welding parameters [28][29][30][31][32][33]. If we consider thermo-mechanical simulation, in addition to the results of temperature distribution, a stress-strain analysis can be obtained.…”

Section: Introductionmentioning

confidence: 99%

Steel Sheets Laser Lap Joint Welding—Process Analysis

Danielewski¹,

Skrzypczyk²

2020

Materials

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This article presents the results of steel-sheet lap-joint-welding using laser beam radiation. The use of a laser beam and keyhole effect for deep material penetration in lap joint welding was presented. Thermodynamic mechanism of laser welding is related to material properties and process parameters. Estimation of welding parameters and joint properties’ analysis was performed through numerical simulation. The article presents a possibility of modeling laser lap-joint welding by using Simufact Welding software based on Marc solver and thermo-mechanical solution. Numerical calculation was performed for surface and conical volumetric heat sources simulating laser absorption and keyhole effect during steel sheet welding. Thermo-mechanical results of fusion zone (FZ), heat-affected zone (HAZ) and phase transformations calculated in numerical simulation were analyzed. The welding parameters for partial sealed joint penetration dedicated for gas piping installations were estimated from the numerical analysis. Low-carbon constructional steel was used for numerical and experimental analyses. A trial joint based on the estimated parameters was prepared by using a CO2 laser. Numerical and experimental results in the form of hardness distributions and weld geometry were compared. Metallographic analysis of the obtained weld was presented, including crystallographic structures and inclusions in the cross section of the joint.

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“…The simulation of a lap joint is complex, and the complexity of the process increases when materials with different thermophysical material properties are to be joined. Realistic results can be obtained by developing an accurate heat source (HS) model andadequate boundary conditions [ 19 , 20 ].…”

Section: Introductionmentioning

confidence: 99%

Numerical and Metallurgical Analysis of Laser Welded, Sealed Lap Joints of S355J2 and 316L Steels under Different Configurations

et al. 2020

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This paper presents the results of laser welding of dissimilar joints, where low-carbon and stainless steels were welded inthe lap joint configuration. Performed welding of austenitic and ferritic-pearlitic steels included a sealed joint, where only partial penetration of lower material was obtained.The authors presented acomparative study of the joints under different configurations. The welding parameters for the assumed penetration were estimated via anumericalsimulation. Moreover, a stress–strain analysis was performed based on theestablished model. Numerical analysis showed significant differences in joint properties, therefore, further study was conducted. Investigation of the fusion mechanism in the obtained joints wascarried out using electron dispersive spectroscopy (EDS) and metallurgical analysis. The study of the lap joint under different configurations showed considerable dissimilarities in stress–strain distribution and relevant differences in the fusion zone structure. The results showed advantages of using stainless steel as the upper material of a microstructure, and uniform chemical element distribution and stress analysis is considered.

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Heat source model for laser beam welding of steel-aluminum lap joints

Cited by 19 publications

References 14 publications

Characterization of Temperature Fields in Laser Beam Welded Hollow-Cylindrical Cold Crack Samples from High Strength Steel 100Cr6

Characterization of Temperature Fields in Laser Beam Welded Hollow-Cylindrical Cold Crack Samples from High Strength Steel 100Cr6

Steel Sheets Laser Lap Joint Welding—Process Analysis

Numerical and Metallurgical Analysis of Laser Welded, Sealed Lap Joints of S355J2 and 316L Steels under Different Configurations

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