Integrative material and process model for the correlation of phase morphology and flow behavior of spheroidization annealed low-alloyed carbon steels

球化退火低合金碳钢相形态与流动行为相关的综合材料和工艺模型

• 批准号: 433641220
• 负责人: Professor Dr.-Ing. Rudolf Kawalla
• 金额: --
• 依托单位: MPA Stuttgart, Otto-Graf-Institut (FMPA)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/433641220?language=en
• 关键词: Integrative; material; process; model; correlation

The mechanical properties of multiphase steel materials such as strength, toughness and ductility do not depend solely on their chemical composition and the volume fraction of phase constituents. Rather, the microstructure morphology used in the course of semi-finished product manufacture and heat treatment, e.g. of spheroidization annealing, has a pronounced influence. For example, the influence of cementite morphology on the mechanical properties of spheroidizing annealed steels has already been demonstrated by various investigations. However, the current state of research lacks a fundamental understanding of the integrative relationship between heat treatment conditions and the resulting flow properties and deformation behaviour of a steel material via the morphology change of its microstructure. The solution to this problem is devoted to this project, in which the complex interactions are determined experimentally and building on that, a numerical model will be created. Various experimental techniques from the field of purely thermal and external stress assisted heat treatment, SEM-in situ-, -2D- and -3D-metallography, the determination of individual phase properties as well as multiaxial bulk forming represent the experimental approach. The numerical model should comprise several simulative tools such as the phase field theory for temporal and spatial development of phases, representative volume elements for determining the final properties of the material and artificial neural networks for transferring the results obtained to other materials. To validate the model, experimental investigations of the practical characterization of formability are required. The results from modelling should contribute to an improved understanding of the relationships between strength properties and deformation behaviour, microstructure development and soft annealing parameters. A practice-relevant advantage opens up by the possibility of being able to control the required flow properties inversely via the established relationships in a targeted manner in accordance with the respective downstream forming process, to save unnecessary hours of annealing and to ensure the interchangeability of steel materials.

多相钢材料的强度、韧性和延展性等机械性能不仅仅取决于其化学成分和相成分的体积分数。相反，在半成品制造和热处理过程中使用的微观结构形态，例如球化退火影响显着。例如，各种研究已经证明了渗碳体形态对球化退火钢机械性能的影响。然而，目前的研究现状缺乏对热处理条件与钢材通过其微观结构的形态变化所产生的流动性能和变形行为之间的综合关系的基本理解。这个项目致力于解决这个问题，其中复杂的相互作用是通过实验确定的，并在此基础上创建一个数值模型。纯热和外部应力辅助热处理、SEM 原位、-2D-和-3D-金相学、单个相特性的确定以及多轴块体成形领域的各种实验技术代表了实验方法。数值模型应包含多种模拟工具，例如用于相的时间和空间发展的相场理论、用于确定材料最终性能的代表性体积元素以及用于将获得的结果转移到其他材料的人工神经网络。为了验证该模型，需要对可成形性的实际表征进行实验研究。建模结果应有助于更好地理解强度特性和变形行为、微观结构发展和软退火参数之间的关系。与实践相关的优势在于，能够根据各自的下游成型工艺，通过已建立的关系以有针对性的方式反向控制所需的流动特性，从而节省不必要的退火时间并确保钢材的互换性材料。