Controlling microstructure and texture development is a key approach to improving the formability of magnesium alloys. In this study, the effects of the strain rate and initial texture on the texture evolution of magnesium alloys during high-temperature processing are investigated. The plane strain compression of three types of AZ80 magnesium alloys with different initial textures was assessed at 723 K and a train rate of 0.0005 s⁻¹. Work softening was consistently observed in the stress–strain curves of all samples. However, the peak stress varied depending on the initial texture, with lower peak stress observed under conditions favoring prismatic slip. Under these conditions, the activation of non-basal slip suppressed the formation of basal texture. The texture shifted and developed parallel to the transverse direction when prismatic slip was dominant. In contrast, the activation of pyramidal slip led to the formation of a basal texture tilted by 25° from the $\left(0001\right)$ plane. The effects of recrystallization and grain boundary migration on texture development were minimal. This study contributes to understanding the texture development mechanisms in magnesium alloys and provides insights into improving their workability and ductility through texture modification.

The increasing demand for ultra-low carbon steel (Interstitial free steel of Ti-Nb composite stabilized type) has underscored the importance of the RH degassing process, which is critical to achieving stringent quality standards and high productivity. This study aimed to boost decarburization efficiency by expanding the lower volume of the RH degasser and adjusting the circulation gas flow rates (190 Nm³/h, 230 Nm³/h, 250 Nm³/h). The effects of these variations on decarburization time, carbon content, and mechanical properties were systematically evaluated. The Enlarged RH degasser (ERH) achieved a higher decarburization rate than the conventional RH degasser (CRH) at the same gas flow rate of 190 Nm³/h, identifying 230 Nm³/h as the optimal rate for ERH. The experimental decarburization times to reach a carbon content of 0.003 wt% in ultra-low carbon steel were 12.4 min for CRH and 10.8 min for ERH, thus reducing the time by 1.6 min. Conversely, the calculated decarburization times were 13.11 min for CRH and 10.75 min for ERH, with ERH showing a reduction of 2.36 min. Consequently, calculated times were 0.76 min longer than experimental times. No significant differences in inclusions were observed between the CRH and ERH at circulation times of 3, 4, and 5 min; however, the mechanical properties of the ERH showed improvements at 4 and 5 min. Therefore, from an economic perspective, 4 min was established as the optimum time. Ultimately, enhancing the lower volume of the RH degasser has increased productivity and decreased production costs.

The purpose of this study is to investigate the effectiveness of laser peening (LP) and shot peening (SP) on the fatigue strength and harmless crack size ( of 3D additively manufactured maraging steel. LP and SP was performed under random condition and pre-optimal condition, respectively. Compressive residual stresses of 510MPa and 1650MPa could be introduced on the surface by LP and SP, respectively. Bending fatigue tests were conducted using base metal (BM) specimen, LP specimen and SP specimen. The fatigue strength of the LP and SP specimens were about 57 and 47% higher than that of BM specimen, respectively. Fatigue fracture was initiated from internal by LP and SP. The semicircular cracks less than 0.3mm and 0.1mm in the depth could be rendered harmless by LP and SP, respectively. The estimated based on fracture mechanics were similar to experimental result. The fatigue strength and was affected by the distribution of the compressive residual stress induced by LP and SP. Thus, the LP and SP process can contribute to improving the reliability of 3D additively manufactured maraging steel. Compressive residual stress is the dominant factor in improving fatigue strength and rendering surface defects harmless.

The effect of initial texture on slip activity, dynamic recrystallization, and basal texture development was investigated in a Mg–9 wt.% Ag alloy during high-temperature plane strain compression. Three sets of specimens with different initial compression planes were machined from a hot-rolled plate and compressed at 723 K and a strain rate of 5.0 × 10⁻² s⁻¹ up to a true strain of −1.0. Microstructure and texture analyses revealed that the initial texture strongly affected the subsequent texture evolution and microstructural development. Sample A, which initially exhibited a strong basal texture, retained and intensified the basal component during deformation, whereas Sample B maintained a transverse direction texture component and showed the lowest flow stress, the highest kernel average misorientation, the lowest dynamically recrystallized fraction, and the retention of coarse unrecrystallized grains. These features suggest that prismatic slip was geometrically favored at the early stage of deformation, resulting in enhanced intragranular deformation and delayed rotation toward the stable basal texture. In contrast, Sample C initially exhibited a rolling direction texture component but rapidly evolved toward a strong basal texture, particularly between true strains of −0.7 and −1.0. Although dynamic recrystallization contributed to grain refinement and local orientation scattering, the final texture evolution was governed mainly by slip induced lattice rotation rather than recrystallization induced texture randomization. These results demonstrate that, although Ag addition can modify flow and recrystallization behavior, basal texture development remains dominant when slip-induced lattice rotation is strongly favored by the imposed plane strain compression geometry.

This study investigated the correlation between mechanical strengthening and electrochemical corrosion behavior in 18Ni300 maraging steel fabricated via laser powder bed fusion (LPBF). To evaluate the impact of post-processing, specimens were analyzed under four conditions: solution treated (S), solution peened (SP), solution aged (SA), and solution aged peened (SAP). The aging treatment (490 °C for 6 h) effectively enhanced the corrosion resistance by homogenizing the martensitic matrix and promoting the formation of a stable passive film, resulting in the lowest corrosion current density ($i_{corr}$ of 1.716 × 10⁻⁶ A/cm²). In contrast, the application of shot peening after aging (SAP) significantly degraded the corrosion resistance, characterized by the most negative corrosion potential ($E_{corr}$ of −0.374 V and a 2.4 times increase in $i_{corr}$ compared to the SA condition. Quantitative analysis revealed that the 1250 MPa of compressive residual stress induced by peening increased the thermodynamic instability of the surface through extreme lattice distortion, thereby lowering the activation energy for anodic dissolution. Furthermore, the increased surface roughness (60.68 µm) expanded the effective electrochemical reaction area, acting as a kinetic accelerator for corrosion. The results demonstrate that while the SA process provides an optimal balance between microstructural stability and corrosion resistance, additional shot peening (SAP) imposes a significant corrosion penalty despite its mechanical benefits. This study concludes that for 18Ni300 maraging steel, the trade-off between mechanical reinforcement and electrochemical stability must be carefully managed, emphasizing the need for surface stabilization when high-intensity peening is applied in corrosive environments.