S.L. Zheng
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Y. Zhang
金属学报(英文版)
A new method for chromate cleaning production named chromite caustic fusion pro-cess, is advanced by Institute of Chemical Metallurgy, the Chinese Academy of Sci-ences. With sodium hydroxide as reaction medium, the new process is composed ofthree procedures: liquid phase oxidation of chromite - metastable phase separation -carbonation ammonium transition. Generally illustrating the new process and its fea-tures, this paper mainly studies the thermodynamics of chromite oxidation. The newprocess has much better practical results than the conventional chromate productionprocess in which sodium carbonate is used as reaction medium. The superiority is alsoshown through thermodynamic studies.``
关键词:
chromite
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A.Q. Lü
,
Y. Zhang
金属学报(英文版)
By means of surface mechanical attrition treatment (SMAT), the grain size with a diameter of about 60nm formed at about 20μm depth and numerous mechanical twins at about 50μm depth from the treated surface were synthesized in 316L stainless steel because of the different distributions of strain and strain rate along depth orientation. For instance the maximum strain rate reached 103-104s-1 on the top surface. The relationship between the microstructure and the corrosion property was studied in 0.05M H2SO4+ 0.25M Na2SO4 aqueous solution, and the results show an extreme improvement of corrosion resistance owing to the appearance of twin boundaries and the obvious reduction in corrosion resistance attributed to the presence of nanocrystaline boundaries.
KEY WORDS surface mechanical attrition trea
关键词:
surface mechanical attrition treatment
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腐蚀性能
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孪晶界
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纳米晶界