Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： Effect of temperature on corrosion behavior of X70 pipeline steel in high pH solution (0.5 mol/L Na2CO3+0.5 mol/L NaHCO3) was studied by means of potentiodynamic polarization, electrochemical impedance spectroscopy and Mott- Schottky measurements. Results showed that the pitting potential, passive current density and the polarization resistance of X70 pipeline steel all decreased with the increase of temperature. In the experimental temperature range, the formed passive film consisted mainly of Fe2O3 and Fe3O4 with features of n-type semiconductor. With the rising temperature, the thickness and donor density of the passive film increased, correspondingly, corrosion tendency of the steel increased. Therefore, the stability of the passive film decreased with the increasing temperature, which weakened the corrosion resistance of the X70 steel.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： The pollution from bulk coal combustion was thought to be one of the main causes of haze weather in northern China, so governments everywhere tried to promote the search for an alternative to civil bulk coal. Specially, so-called “clean energy” was vigorously promoted and coal-to-electricity or natural gas conversion project was implemented in the Beijing-Tianjin-Hebei metropolitan area, while burning high-quality anthracite and semicoke was encouraged in the surrounding areas, though giving rise to unsatisfactory influence finally. Several typical decentralized civil heating technologies in China were comparatively analyzed in this article. It is suggested that the coal-to-electricity or natural gas conversion project must be on the premise of rich resources, suitable geographic conditions, and high-level economic development as well as conforming to living habits of the local people, among which the economic affordability is one of the key factors to success. In order to solve the pollution problem of bulk coal combustion in remote low-income rural areas thoroughly, a long-term plan should be made to realize clean heating by burning bituminous briquette in environment-friendly domestic furnaces such as decoupling combustion stoves.
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