Materials Engineering - Metals and alloys - Multiscale deformation modelling of small scale mechanical tests

繁荣伙伴关系项目的目标之一是通过小规模试验准确评估大量钢材的机械性能。炼钢过程中力学行为的一个重要方面是由轧制过程引起的各向异性屈服和加工硬化。冷轧和热轧都会产生冶金织构，影响机械性能和随后的成形过程。这是一个特殊的问题，用于金属成型薄板钢，如深拉深等级。随着变形材料尺寸的减小，微观结构的影响越来越大，连续体建模方法的精度越来越低。利用晶体塑性有限元模型（CPFEM）对微观结构进行变形建模，可以对各向异性变形和损伤进行预测。繁荣伙伴关系已经采用了连续体建模方法；然而，将CPFEM与连续变形模型结合起来进行小型机械试验，如小冲孔和剪切压缩，将允许更准确地评估微观力学行为。然后，这些模型可以应用于更大规模的变形过程，例如使用多尺度方法进行轧制，然后可以应用于更大规模的变形。该项目的主要目标是为特定等级的钢开发CPFEM模型。该模型将使用基于具有微观结构数据（如晶粒和相形态）的代表性体积元素（RVEs）的多尺度方法，针对小规模测试数据进行验证。该方法将用于预测小规模试验中的损伤，以及用于评估单阶段和多阶段变形过程中各向异性的演变。目标是最终将该模型应用于不同尺寸的轧制几何形状，从而预测扩大轧制过程的影响。最初，该模型将应用于环境温度下的变形，稍后将扩展到更高的温度。多尺度方法将补充作为繁荣伙伴关系一部分正在开发的连续模式。

One of the aims of the Prosperity Partnership project is to accurately evaluate the mechanical properties of a large number of steels from small scale tests. An important aspect of mechanical behaviour during steel making is anisotropic yield and work-hardening caused by rolling processes. Both hot and cold rolling result in metallurgical texture which effects mechanical properties and subsequent forming processes. This is a particular issue for thin sheet steels used for metal forming such as deep drawing grades.As the size of the deforming material becomes smaller, the influence of microstructure becomes greater and continuum modelling approaches become less accurate. Modelling deformation of the microstructure using crystal plasticity finite element modelling (CPFEM) allows predictions of anisotropic deformation and damage to be made.A continuum modelling approach is already being used in the Prosperity Partnership; however, combining CPFEM with continuum deformation models for small scale mechanical tests such as small punch and shear compression will allow a more accurate evaluation of micromechanical behaviour. These models can then be applied to larger scale deformation processes such as rolling using a multiscale approach which can then be applied to larger scale deformationThe primary aim of the project is to develop a CPFEM model for specific grades of steel. The model will be validated against small scale test data, using a multiscale approach based on representative volume elements (RVEs) with microstructural data such as grain and phase morphology. This approach will be used to predict damage in small scale tests as well as being used to evaluate the evolution of anisotropy during single and multi-stage deformation. The aim will be to ultimately apply the model to different sized rolling geometries, allowing predictions of the effects of scaling up the rolling processes. Initially the model will be applied to deformation at ambient temperature, with scope to extend to higher temperatures later. The multiscale approach will complement continuum models being developed as part of the Prosperity Partnership.