Electron beam welding is an autogenous welding process that leads to microstructural heterogeneities; crystallographic texture, elongated and larger grain size relative to the surrounding parent material. The goal of this study is to predict the changes in mechanical response of the weld fusion zone as a function of grain morphology and texture by using the parent material properties to avoid extensive and costly experimental campaigns. For this reason, a crystal plasticity solver, “University of BRIstol cryStal plasTicity sOLver” (BRISTOL), is implemented in a finite element framework with new constitutive laws to account for the length-scale dependence considering the size and shape of the grains. It is found that the crystallographic texture governs the orientation specific elastic stiffness and yield stress having the most dominant effect on the macroscopic response of the weldment at the grain size scales considered. Crucially the length-scale dependent model allows accurate prediction of the yield strength of the weldment over a range of microstructures, also highlighting the presence of other factors such as prior strain hardening during the welding process and residual stresses.

电子束焊接是一种自熔焊接工艺，会导致微观结构不均匀；晶体结构，相对于周围母体材料细长且晶粒尺寸较大。本研究的目的是通过使用母材特性来预测焊接熔合区的机械响应随晶粒形态和纹理的变化，以避免进行广泛且昂贵的实验活动。为此，晶体塑性求解器“University of BRI stol cry S tal plas T icity s OL ver”（BRISTOL)，在具有新本构定律的有限元框架中实施，以考虑晶粒的大小和形状来解释长度尺度依赖性。研究发现，晶体织构控制取向比弹性刚度和屈服应力，在所考虑的晶粒尺寸尺度上对焊接件的宏观响应具有最主要的影响。至关重要的是，长度尺度相关模型可以准确预测焊件在一系列微观结构上的屈服强度，还可以突出其他因素的存在，例如焊接过程中的预先应变硬化和残余应力。