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A strategy based on representative volume element (RVE) was proposed to investigate the mechanical behavior of cold-drawn pearlitic steels at multiscale. Firstly, a finite element model based on macroscale was used to simulate the cold drawing. The partial mesh of the model was refined to obtain a RVE-scale element, and the elastic-plastic strain of this element were extracted and mapped to the RVE model. For further research, a high-resolution RVE model based on the crystal plasticity finite element method (CPFEM) was established to investigate the mechanical behavior of the pearlite. In addition, a new method of hierarchical partition was used for geometric modeling. Crucially, the simulated pole figures were in high agreement with the experimental results, both prominently showing an α-fiber texture. The final results indicated that the plasticity and strength of the pearlitic steels were determined by the coordinated deformation between pearlite nodules and the interaction between ferrite and cementite.

With the rapid development of rail vehicles, 301L strip has become the main material of the rail vehicles, and its flatness quality has got much attention. Meanwhile, 20-roll mill becomes the most important cold rolling equipment for 301L strip forming, because of its high precision and wide application. To study the flatness control theory of cold rolling 301L strip in 20-roll mill, a finite element model is established based on elastoplastic theory. The stress–strain field is used to characterize the strip flatness under different rolling parameters. After analysis, the results show that the front and back tension have the most obvious effects on strip flatness. The friction coefficient and rolling speed are beneficial to the control of the strip flatness when they increase within a certain range.

To provide new possibilities for electrode materials, a new welding method of Al/Ni dissimilar metals was studied using molecular dynamics in this research. The effective bonding between aluminum and nickel was achieved by Al-Ni reactive nano-multilayers (RNMLs). The tensile strength of the bonded component was 57 % higher than that of diffusion-bonded Al/Ni nanowires. First, compared to the two single-crystal metals before bonding, the Young’s modulus of the bonded component was 48.88 GPa higher than that of single-crystal aluminum and 68.09 GPa lower than that of single-crystal nickel. Furthermore, a large number of stair-rod dislocations and nano-coherent twins were generated in the process of tensile loading, improving the mechanical performance of the bonded component. Second, as the atomic ratio of Al-Ni RNMLs increased, the tensile strength decreased first to 6.22 GPa and then continuously increased to 7.48 GPa, and the Young’s modulus increased from 113.73 to 141.73 GPa and remained stable. When the atomic ratio was 1.98, Shockley dislocations and stair-rod dislocations were more easily generated. Similarly, an ignition temperature of 830 K resulted in the highest tensile strength of the bonded components among all of the RNMLs ignition temperatures.