## 1 Introduction
These descriptions originated from the observations of metallography images and did not link to any physical parameters and intuitions about the welding process. Currently, the most commonly used model is MINA [9], which predicts the orientations based on the information from the welder's notebook. Representing the weld deposition process phenomenologically provided a mathematically simple framework with parameters directlylinked to weld manufacturing. However, MINA has its limitations, both with regard to welding methods it can cover and allowable weld complexity. The literature offers several approaches to modelling weld microstructures numerically, considering specific simplifying assumptions about grain geometry or orientation [14; 15; 16; 17; 18]. The finite element analysis (FEA) is suitable for solving various problems in solid mechanics, heat transport and other physical domains. However, FEA is primarily a continuum technique and, until recently, had limited uptake for simulating the microstructural mass transfer and evolution, both inherent in the welding process. Finite element modelling of welding encapsulates rather complex phenomena and involves considerable effort. On the other hand, the intuition is that only a portion of the information provided by such models is used in imaging. For instance, solidification simulations often focus on predicting residual stress in welds, an aspect of little benefit for supporting ultrasonic imaging. Further, such an FE model often requires numerous input parameters (bead shapes, location, source power, material properties and composition, etc.) and only a fraction of this can be recovered from the manufacturing procedure. A significant proportion needs to be inferred, calculated based on some assumptions or assumed based on limited detailed studies available. This manuscript reports on a case study shedding light on the much-desired pragmatic balance between the simulation cost and its accuracy when employed as a supporting tool for ultrasonic imaging. The aim of the paper is to assess different levels of complexity of the numerical weld formation model. We use a case study of a V-veld austenitic weld which was manufactured for the ADVISE project. However, the present study focuses on the impact of weld formation model parameters on corrected delay laws for imaging and hence, uses only numerical simulations to better expose the effect of the considered configurations. To the authors' knowledge, finite element modelling of welding has not been extensively used to support ultrasonic imaging. Computational cost and complexity are the main reasons for preferring simple descriptions; however, the versatility of finite elements enables the capturing of a broader range of configurations, geometries, welding methods, and contexts. This paper reports on the development of a simplified finite element procedure, considerably reducing the calculation time. With this tool, we performed a parametric study analysing the effect of several weld formation model parameters on imaging. We consider a specific use case--an austenitic stainless steel mock-up manufactured during this research. While this is an isolated example, the insight we offer will hopefully provide a better understanding of the importance of weld formation model parameters and guide further research on this topic. To our knowledge, this is the first comprehensive study devoted to the use of finite element welding simulation in supporting ultrasonic inspection. We adopt an ultrasonic imaging perspective and evaluate the effect of the welding simulation parameters by analysing TFM images computed using the delay laws based on weld formation simulation. This approach focuses on the end-user and generates insights directly relevant to the NDE community, striking a pragmatic balance between the approximations in welding simulation and the requirements of imaging algorithms. We show that coupled thermo-mechanical simulation is not necessary to deliver material information suitable for imaging.