Integrated Process Simulation of Non-Oriented Electrical Steel

[d=A]A tailor-made microstructure, especially regarding grain size and texture, improves the magnetic properties of non-oriented electrical steels. One way to adjust the microstructure is to control the production and processing in great detail. Simulation and modeling approaches can help to evaluate the impact of different process parameters and finally select them appropriately. We present individual model approaches for hot rolling, cold rolling, annealing and shear cutting and aim to connect the models to account for the complex interrelationships between the process steps. A layer model combined with a microstructure model describes the grain size evolution during hot rolling. The crystal plasticity finite-element method (CPFEM) predicts the cold-rolling texture. Grain size and texture evolution during annealing is captured by the level-set method and the heat treatment model GraGLeS2D+. The impact of different grain sizes across the sheet thickness on residual stress state is evaluated by the surface model. All models take heterogeneous microstructures across the sheet thickness into account. Furthermore, a relationship is established between process and material parameters and magnetic properties. The basic mathematical principles of the models are explained and demonstrated using laboratory experiments on a non-oriented electrical steel with 3.16 wt.% Si as an example. Improving the magnetic properties of non-oriented electrical steels are of high interest. In this context, improvement by a tailor-made microstructure, especially regarding grain size and texture, is one focus. One way to adjust the microstructure is to control the production and processing in great detail. Simulation and modeling approaches, emphasizing grain size and texture development, can help to evaluate and finally set process parameters. Here, we present individual model approaches for hot rolling, cold rolling, annealing and shear cutting and aim to connect the models to account for the complex interrelationships between the process steps. Furthermore, a connection between the process parameters and the magnetic properties is drawn. Grain size, grain size distribution, texture and dislocation density are the main transfer parameters in between the models. All models take heterogeneous microstructures across the sheet thickness into account. The basic mathematical principles of the models are explained, and a case study is presented in each case using FeSi3.2wt%Si as an example material.

Development and Characterization of Pectin Films with Salicornia ramosissima: Biodegradation in Soil and Seawater

Pectin films were developed by incorporating a halophyte plant Salicornia ramosissima (dry powder from stem parts) to modify the film’s properties. The films’ physicomechanical properties, Fourier-transform infrared spectroscopy (FTIR), and microstructure, as well as their biodegradation capacity in soil and seawater, were evaluated. The inclusion of S. ramosissima significantly increased the thickness (0.25 ± 0.01 mm; control 0.18 ± 0.01 mm), color parameters a* (4.96 ± 0.30; control 3.29 ± 0.16) and b* (28.62 ± 0.51; control 12.74 ± 0.75), water vapor permeability (1.62 × 10−9 ± 1.09 × 10−10 (g/m·s·Pa); control 1.24 × 10−9 ± 6.58 × 10−11 (g/m·s·Pa)), water solubility (50.50 ± 5.00%; control 11.56 ± 5.56%), and elongation at break (5.89 ± 0.29%; control 3.91 ± 0.62%). On the other hand, L* (48.84 ± 1.60), tensile strength (0.13 ± 0.02 MPa), and Young’s modulus (0.01 ± 0 MPa) presented lower values compared with the control (L* 81.20 ± 1.60; 4.19 ± 0.82 MPa; 0.93 ± 0.12 MPa), while the moisture content varied between 30% and 45%, for the film with S. ramosissima and the control film, respectively. The addition of S. ramosissima led to opaque films with relatively heterogeneous microstructures. The films showed also good biodegradation capacity—after 21 days in soil (around 90%), and after 30 days in seawater (fully fragmented). These results show that pectin films with S. ramosissima may have great potential to be used in the future as an eco-friendly food packaging material.

Cellular Automata-based computational library for development of digital material representation models of heterogenous microstructures

The development of an efficient numerical approach for the generation of a wide range of heterogeneous microstructures models with the application of the lean workflow concept is presented in the paper. First, the idea and implementation details of the developed cellular automata-based computational library allowing the development of digital material representation models within a workflow are presented in the paper. Such an approach provides the desired flexibility in the generation of various digital models of heterogenous microstructures. Therefore, the proposed library is mostly implemented within the object-oriented C + + programming language with the assumption of modularity. In this case, the main part of the application consists of classes and methods, which can be treated like base elements to be inherited and extended in other libraries. Each additional dynamic link library implements particular algorithms for the generation of specific microstructure features in the digital model within the unified data structures that allow the application of the workflow concept. The set of developed libraries and their assumptions are described as case studies to show the capabilities of the presented solution. Finally, examples of practical applications of the developed library in the full-field numerical simulations of complex material deformation are presented at the end of the paper.