Figure 9
The figure presents paired scanning electron microscopy (S E M) images and energy-dispersive X-ray spectroscopy (E D S) spectra for four conditions, arranged in four rows. The left column shows S E M morphology images labeled (a), (b), (c), and (d), while the right column shows the corresponding E D S spectra labeled (a 1), (b 1), (c 1), and (d 1). Each S E M image includes a scale bar of 10 micrometers. Panel (a) shows rod-like and plate-like particles distributed unevenly across a lighter background, with several clustered regions of elongated rectangular grains. Individual particles appear relatively large and sparsely packed, with noticeable agglomeration in localized areas. Panel (a 1) displays the E D S spectrum for (a), plotted as counts per second per electron volt versus energy in kiloelectron volts. The horizontal axis is labeled “kiloelectron volts”, ranging from 0 to 15 with an interval of 5, and the vertical axis is labeled “c p s per electron volt”, ranging from 0 to 150 with an interval of 50. Strong peaks are labeled for O, V, and F e, with additional smaller peaks corresponding to elements such as M n, C r, S i, and C u. Iron and oxygen dominate the spectrum, indicating an F e-based oxide composition with minor alloying elements. Panel (b) shows a denser microstructure composed of smaller, more uniformly distributed blocky and angular particles. Compared with (a), the grains are more compact and closely packed, forming a continuous granular surface. Panel (b 1) has the horizontal axis labeled “kiloelectron volts”, ranging from 0 to 15 with an interval of 5, and the vertical axis labeled “c p s per electron volt”, ranging from 0 to 200 with an interval of 50. The E D S spectrum for (b), again, shows prominent O, V, and F e peaks, with detectable signals from M n, C r, S i, and C u. The relative intensities differ slightly from (a 1), but iron and oxygen remain the primary constituents. Panel (c) presents a microstructure of tightly packed, short prismatic, and cuboid-shaped particles with sharper edges. The surface appears more homogeneous than in (a) and (b), with reduced large agglomerates and a finer overall grain size. Panel (c 1) shows the corresponding E D S spectrum, featuring strong O, V, and F e peaks and smaller contributions from M n, C r, S i, and C u. The elemental profile is similar to (b 1), with iron and oxygen still predominant. The axes are the same as in b 1. Panel (d) displays the most compact morphology among the four, consisting of densely packed, irregular polygonal particles. The grains appear smaller and more uniformly distributed, producing a relatively continuous textured surface. Panel (d 1), the E D S spectrum for (d), again highlights O, V, and F e as the major elements, accompanied by minor peaks for M n, C r, S i, and C u. Compared with the other spectra, the relative peak heights show subtle variations, but the overall elemental composition remains consistent across all samples. The axes are the same as in b 1. Note: All the numerical data values are approximated.SEM images of Q235 steel samples at 298 K under different concentrations of acidic cleaning agents (a–d): (a) 5% cleaning agent, (b) 10% cleaning agent, (c) 15% cleaning agent,(d) 20% cleaning agent; EDS quantitative analysis images (a1-d1), (a1) 5% cleaning agent, (b1) 10% cleaning agent, (c1) 15% cleaning agent, (d1) 20% cleaning agent. Source(s): Authors’ own work