To investigate the correlation between structure characteristics and wear resistance of CO2 corrosion product scales at high temperature and high pressure, an autoclave was used to prepare CO2 corrosion product scales on N80 steel in carbon dioxide corrosion environment. The correlation between wear resistance of the scales and many other factors, such as temperature, pressure, morphology, structure, velocity of fluid medium, sand grain size, and so on, was comparatively analyzed by a self assembled wear device, and the scale morphologies before or after being worn were observed by scanning electron microscope (SEM). And then the surface grain size and thickness of scale were measured. The results showed that the cross section of the corrosion scale was of a double layer structure, the outer layer of which was composed of regular crystals, whereas the inner layer was a thin scale of fine grains. The outer grain size and thickness of scale varied with temperature, and the initial wear loss was consistent with the surface grain size; at the same time, the total wear loss corresponded to the thickness of scale. Compared to wear resistance in different depths of the scale, it was found that the structure of scale was a double layer structure in cross section, and the wear resistance of inner layer was better than that of the outer layer; the closer the scale to the matrix, the greater was the wear resistance of scale; and the larger the size or the higher the rotary speed of solid grain in multiphase flowing medium, the more was the wear loss of scale. 相似文献
This paper reports on how the blend ratio and morphology influence the mechanical, thermal, thermomechanical, and rheological properties of poly(propylene) (PP)/low density polyethylene (LDPE) blends. The blend morphology is composed of the major matrix phase and the minor phase, with subinclusions of the major matrix existing within the minor phase. Blends containing low amounts (<20 wt%) of either phase exhibit partial miscibility but the phases are immiscible at higher contents. Partial miscibility of the blends is revealed by scanning electron microscopy studies showing fibril‐like structures and confirmed by rheology. The tensile modulus of the blends decreases with increasing amounts of LDPE, but low LDPE contents exhibit positive deviation from the mixing rule of mixture due to partial compatibility. The crystallinity of PP is affected less than that of LDPE in the blends. Thermomechanical and rheological properties of neat polymers are significantly influenced by blending. The blend ratio and morphology influence impact strength and elongation at break, and the result demonstrates that the 80/20 PP/LDPE blend offers a balance among the mechanical and material properties that are essential for flexible packaging applications.
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