The equiaxed compression test was used to study the microstructure evolution and the dynamic recrystallization behavior of 2205 duplex stainless steel during hot deformation under 850–1100 °C with strain rates of 0.01 s⁻¹, 0.1 s⁻¹, 1 s⁻¹ and 10 s⁻¹. The calculated values of thermal deformation activation energy Q and stress index n were 351.58 kJ mol⁻¹ and 3.8543, respectively. On this basis, the Arrhenius type constitutive equation was successfully established, the microstructure of the sample was studied by electron backscatter diffraction (EBSD), and the changes of the ferrite and austenite phase under different deformation parameters were analyzed. It was seen from the phase boundary and grain boundary diagrams that, at the same temperature, as the deformation rate increased, the austenite phase content slowly decreased, while the ferrite phase content increased. The deformation amount of the two phases under the same strain at different temperatures and strain rates were respectively obtained from the grain orientation scatter diagram and the changes of recrystallization, deformation and substructure under different deformation parameters were obtained from the recrystallization diagram.

The study aims to investigate the influence of environmental media on the friction and wear behavior of low-alloy wear-resistant steels and to provide practical references for their application. This article conducted sliding wear tests on NM500 wear-resistant steel under different loads under air atmosphere, deionized water, and 3.5 wt% NaCl solution conditions. Someone quantitatively measured the friction coefficient and wear amount of each friction pair. The present study employed scanning electron microscopy, energy dispersive spectroscopy, and a white light interference three-dimensional surface profiler to analyze the surface structure, cross-sectional morphology, element distribution, and wear mechanism of the wear scars under various experimental conditions. The results show that: In deionized water, NM500 has the best wear resistance, while the dry state is the worst. The lubricating and cooling effect of the liquid, as well as the corrosive effect of the NaCl solution, play an essential role in the wear behavior of NM500. Under dry friction conditions, the wear mechanism of NM500 is principally adhesive wear, fatigue wear, and oxidation wear. In the case of wear testing in deionized water, the researchers characterized the dominant wear mechanism as adhesive wear in conjunction with fatigue wear and abrasive wear. In contrast, when they carried out the wear testing in NaCl solution, the wear mechanism was primarily driven by corrosion wear and adhesive wear, with only a minor contribution from fatigue wear.

The Gleeble-3800 thermal simulator was used to perform hot compression experiments on Q345 steel at a temperature of 1123~1373 K, a strain rate of 0.01~10 s⁻¹, and 60% deformation. Analysis of the flow curves of Q345 steel revealed that flow stress decreases with the increase of deformation temperature and decrease of strain rate. According to the stress–strain curve of Q345 steel, three constitutive models of Johnson–Cook, Modified Johnson–Cook and strain-compensated Arrhenius were established. By comparison, it was found that the strain-compensated Arrhenius model has higher accuracy, and its correlation coefficient and average relative error are 0.995 and 4.93%, respectively. In addition, the thermal processing map of Q345 steel was established, and the optimal processing range was temperature 1253–1373 K, strain rate 0.5–10 s⁻¹.

The surface of Inconel 625, a nickel-base alloy, was strengthened by vacuum electron beam scanning technology. The evolution of its microstructure was analyzed by electron backscatter diffraction (EBSD) and the friction and wear tester (RETC). The results show that the FCC phase in the microstructure of Inconel 625 nickel-base alloy is stripped and islanded after electron beam scanning treatment. The austenite texture type changes and finally forms a typical cubic texture with a certain strength of S texture. With the increase in temperature of the focusing current, the wear resistance of nickel-base alloy plates first increases and then decreases. Under a 720 mA focusing current, the wear volume and wear rate are the lowest, which are 0.141525 mm³ and 1.41525 × ${10}^{-5}{ \mathrm{mm}}^3$/N∙m, respectively. The wear rate decreases by 26.64%, which may be related to the columnar crystals produced in the melting area. After electron beam surface modification, the oxidation wear and adhesive wear are relatively smaller than the original materials.