中华人民共和国国家标准 粉末冶金用还原铁粉

本标准适用于粉末冶金制品用的还原铁粉。 1.名词术语还原铁粉——系指用还原法制得的铁粉。 2.品种和规格 2.1 还原铁粉按其使用要求,分成三种牌号。     

利用钢渣制备颜料型磁性氧化铁粉的试验研究

以磁选钢渣为原料,采用低温焙烧—磁选工艺,可以制备出颜料型磁性铁粉。借助化学分析、XRD分析和着色力分析等手段,研究了焙烧温度和时间对磁选钢渣制备的颜料型磁性铁粉的组成和性能的影响。结果表明:磁选转炉钢渣可以制备具有高着色力和遮盖力的颜料型磁性铁粉;随着反应温度的升高,磁性铁粉的w(Fe)和着色力均呈升高的趋势,而遮盖力呈降低的趋势;随着反应时间的延长,磁性铁粉的着色力呈升高趋势,而遮盖力呈先升高后降低的趋势,当反应时间为30min时,其遮盖力最大,为56g/m2。     

Recrystallization of electrolytic iron powders

Translated from Poroshkovaya Metallurgiya, No. 2, pp. 4–5, February, 1991.     

Pressing behavior of atomized iron powders

Conclusions The porous structure of the particles of an atomized iron powder depends on the chemical composition and sieve analysis of the starting powder and also, to a smaller extent, on its own sieve analysis, as determined by the conditions of milling of the sponge produced by annealing. In our study of various powder batches the best combination of degree of particle sponginess and agglomeration and hence pressing characteristics was found to be ensured by the use of a cast iron starting powder containing about 50% of a fine fraction, < 0.063 mm, with a comparatively low oxygen content (6.5%). With the atomized powders, the transition from the first stage of pressing to the second took place more gradually and at a higher pressing pressure (600 MPa) than with the reduced powder (450 MPa). It is shown that the compressibility of an iron powder is the better the greater the contribution from the first stage and hence the smaller the role of the volume plastic deformation of the particles in the attainment of a given density. The best compressibility with a low degree of contanimation with carbon and oxygen can be attained at minimum values of specific surface, degree of sponginess , and degree of agglomeration and also a maximum apparent density resulting from the use of powders of equiaxed particle shape close to spherical. The steady increase in compressibility with increasing apparent and tap densities that is characteristic of reduced iron powders is not always observed with powders pro-duced by atomization and annealing.Translated from Poroshkovaya Metallurgiya, No. 2(218), pp. 23–29, February, 1981.     

Electroless nickel plating of iron powders

Summary A new method, based on the reaction of reduction of nickel ions by hypophosphite in aqueous solutions, is proposed for the electroless nickel plating of iron powders. An electrolyte and a nickel plating procedure have been developed which yield deposits of high quality.Translated from Poroshkovaya Metallurgiya, No. 11 (47), pp. 7–8, November, 1966.     

Pressing behavior of atomized iron powders

Conclusions To facilitate prediction of optimum conditions of manufacture of atomized iron powders, a formula has been derived relating the compressibility of a powder to the properties of its particles at various stages of the process of atomization and annealing. Specific examples are quoted showing that, under conditions of adequate reduction (less than 0.8% O) and decarburization (less than 0.08% C), it is possible, by suitable regulation of the degrees of sponginess and agglomeration, to produce atomized iron powders possessing the required properties.Translated from Poroshkovaya Metallurgiya, No. 3(219), pp. 32–37, March, 1981.