Quality Control Of Water-atomized Pre-alloyed Steel Powder And Influence Of Alloying Methods On Its Properties

Water atomization is a technique that can commercially and high-efficiently manufacture iron & steel powders. The key in their production technique is the high-pressure water atomization and the green powder reduction at an elevated temperature. The properties of ferrous powder metallurgy materials can be improved by powder's alloying technique. In this paper, the effects of manufacture technique on water-atomized pre-alloyed steel powder and alloying method on the properties of ferrous Powder Metallurgy materials were studied systematically. Also, the influences of steel smelting ,atomization and reduction on the chemical composition and physical-technological properties of the steel powder were investigated in detail. The conclusions are as follows:(1) High-pressure water-atomization can be used to produce a pre-alloyed steel powder with high apparent density, high green strength, size-stability after sintering and low hydrogen-loss content;(2) The higher smelting temperature and/or water pressure, the finer particle size of steel powders;(3) When the atomization angle holds in a reasonable value's range the obtained powder will have a better particle size distribution;(4) An optimum atomization technological parameters: liquid steel flux, water pressure and water prick angle was obtained(5) Reduction variables ( temperature, holding time, material-bed'sthickness and reducing gas flux) have a significant effect on the particle agglomeration and properties of final powder was given(6) Different alloying methods were developed to modify properties of ferrous Powder materials and hence to broaden its applications in ferrous powder metallurgy industry.