Original language | English |
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Title of host publication | Encyclopedia of Thermal Stresses |

Editors | Richard B. Hetnarski |

Publisher | Springer |

Pages | 1633-1645 |

ISBN (Electronic) | 978-94-007-2739-7 |

ISBN (Print) | 978-94-007-2738-0 |

DOIs | |

Publication status | Published - 2014 |

## Abstract

Welding is a popular method of forming joints between metal components. The most common type is fusion welding, in which a heat source is applied to melt the material before it re-solidifies to form the joint. This procedure involves intense heat cycles, responsible for non-linear material behavior and usually inducing substantial thermal stresses. Following the process of welding, thermal stresses are mostly locked in the material, and therefore they are termed residual stresses. Residual stresses can often be detrimental to the structural integrity and mechanical performance of a welded component, in which case they ought to be mitigated by performing procedures such as post-weld heat treatment (PWHT). Both numerical and experimental techniques are used to quantify residual stresses in order to predict their effect on the mechanical behavior of the component. At present, one of the most effective methods of determining thermal stresses in welded components is the finite element (FE) numerical method.

The heat required to melt the material during fusion welding is commonly generated using an electric arc between an electrode and the materials being welded. The simulation of the heat source in the application of the FE method can be challenging and so can the determination and selection of appropriate data to represent the physical and mechanical behavior of the modeled materials. In the following sections, the FE method of numerically simulating the process of fusion welding of metal components is presented. A typical welding procedure, including PWHT, is briefly specified. The FE simulations of fusion welding and PWHT to determine thermal stresses and any resulting deformations are described. Examples are given of three-dimensional (3D) as well as two-dimensional (2D) axisymmetric simulations of the welding of high strength steel and nickel-base superalloy components, including how to simulate thermal and structural material behavior and solid-state phase transformations (i.e. martensite↔austenite).

The heat required to melt the material during fusion welding is commonly generated using an electric arc between an electrode and the materials being welded. The simulation of the heat source in the application of the FE method can be challenging and so can the determination and selection of appropriate data to represent the physical and mechanical behavior of the modeled materials. In the following sections, the FE method of numerically simulating the process of fusion welding of metal components is presented. A typical welding procedure, including PWHT, is briefly specified. The FE simulations of fusion welding and PWHT to determine thermal stresses and any resulting deformations are described. Examples are given of three-dimensional (3D) as well as two-dimensional (2D) axisymmetric simulations of the welding of high strength steel and nickel-base superalloy components, including how to simulate thermal and structural material behavior and solid-state phase transformations (i.e. martensite↔austenite).