In this paper, the relationship between Kernel average misorientation (KAM), geometrically necessary dislocation (GND) density and dislocation structures of Nb-bearing austenitic stainless steel under low cycle fatigue (LCF) was studied at 600°C at the total strain amplitude ranged from 0.3% to 1.0%. The results based on EBSD analysis show that the GND density in fatigue specimens gradually increases with the increase of strain amplitude. Under LCF loading, the dislocation structures are mainly planar slip bands (PSBs) and the cell structures. With the increase of strain amplitude, the number of PSBs increases with decrease in width, and the average diameter of cells also decreases. The PSBs originate due to the dynamic strain aging (DSA) effect, and DSA is more significant under high strain amplitude. The average diameter of cell structures has a specific relationship with GND density.

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On the one hand, accordingly to remove the surface impurities, we purified the prepared Multi-walled carbon nanotubes (MWCNTs) in our advance experiment; ferrous ions and iron ions in lye through the action of micro-filtration membrane to form smaller size Fe3O4 magnetic particles on the other hand. The prepared magnetic Fe3O4 with small particle size was loaded on the adorption point of the multi-walled carban nanotubes(MWCNTs) to form magnetic carbon nanocomposites. In order to achieve the best adsorption effect, the preparation temperature was improved in the experiment, and the influence of the ratio of ferrous ions to iron ions on the properties of the material was adjusted. The best adsorption properties of the composites were confirmed by X-ray diffraction and Fourier infrared spectrometer phase analysis. In addition, the application of this experiment to water treatment has a good effect on the copper ion removal.

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A copper/Q235 steel/copper composite block with excellent bonding interfaces was prepared by explosive welding which was a promising technique to fabricate laminates. The microstructure and mechanical properties of the interfaces were investigated via the tensile-shear test, optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM), and electron back-scattered diffraction (EBSD). The results showed that the shear strength of the upper-interface and lower-interfaces of the welded copper/steel are higher than ~235 MPa and ~222 MPa, respectively. The specimens failed fully within the copper and not at the bonding interface. It was attributed to: (1) no cavities and cracks at the interface; (2) the interface formed a metallurgical bonding including numerous ultra-fine grains (UFGs) which can significantly improve the plastic deformation coordination at the interface and inhibit the generation of micro-cracks.