Investigation of combined influence of skin pass rolling and roller straightening of a thin sheet made of materials with different crystal lattice on microstructure, texture, static and fatigue strength

平整轧制和辊式矫直是板材生产的最终工序，决定了产品的显微组织和机械性能。在初步调查中，它表明，这些形成操作的影响的强度取决于材料的晶格结构。需要进一步研究平整轧制单调成形（导致材料加工硬化）和辊矫直循环成形（可能导致加工硬化或加工软化）对板材性能的综合影响。由于钣金件在后续操作中不仅要承受静态机械应力，而且还要承受周期性机械应力，因此除了加工硬化或软化之外，残余应力状态也具有重要意义。因此，需要对静态和循环应力下的机械性能进行全面的材料表征。该计划项目的工作方案包括分析静态和周期性应力下的机械性能变化，以及研究各种平整轧制和轧辊矫直条件下（包括S形轧辊）的板材微观结构和织构。计划中的研究项目的科学目标是研究平整轧制过程中的单调成形和辊式矫直过程中的循环成形对不同晶格材料（DC 01，Cu，α-Ti）的微观结构、织构、残余应力水平和符号以及静态和循环实验框架内的机械性能的综合影响。该项目的实际目标是开发一种适当的技术，通过光整轧制的单调成形和辊矫直条件的循环成形的适当组合，生产具有负载调整的微观结构、纹理和高静态和疲劳强度的板材。

Skin pass rolling and roller straightening represent the final operations in sheet production and decisively determine the resulting microstructural and mechanical properties of the products. In preliminary investigations, it was shown that the intensity of the influence of these forming operations depends inter alia on material lattice structure. Further investigation is required on the combined influence on sheet properties as a result of monotonous forming by skin pass rolling which induces material work hardening and cyclical forming by roller straightening, which could induce either work hardening or work softening. Since sheet metal parts are subject to not only static but also cyclical mechanical stresses in later operations the residual stress state is of essential significance in addition to work hardening or softening. Thus, a comprehensive material characterization is required concerning mechanical properties during static and cyclical stresses. The work programme of the planned project includes the analysis of changes in mechanical properties during static and cyclical stresses as well as the investigation of microstructure and texture of sheets during various skin pass rolling and roller straightening conditions including the s-shape enclosing the rolls. The scientific aim of the planned research project is the investigation of combined influence of monotonous forming during skin pass rolling and cyclical forming during roller straightening of sheets made of materials with different crystal lattices (DC01, Cu, Alpha-Ti) on microstructure, texture, the level and sign of residual stresses, and the mechanical properties within the framework of static and cyclical experiments. The practical aim of the project is the development of an appropriate technology for production of sheets with load-adjusted microstructure, texture, and a high static and fatigue strength by a suitable combination of monotonous forming by skin pass rolling and cyclical forming by roller straightening conditions.