气固两相流雾化法制备微细不锈钢粉末

Fabrication of fine stainless steel powder by gas andsolid dual-phase atomization

采用含有固体食盐颗粒的气固两相流雾化工艺制备不锈钢粉末,并讨论了金属液流量、固体介质流量、气体介质流量以及气压等工艺参数对粉末粒度和形貌的影响。研究结果表明:在同等气体压力和流量的条件下,与普通气体雾化相比,气固两相流雾化所得不锈钢粉末具有更小的粒度和更好的球形度;随着气体介质流量及压力的增加,所制备的不锈钢粉末粒度越小,粉末的分布更集中;随固体介质盐流量的增大,所得粉末的粒度呈现先减小后增大的趋势。在熔体温度为1550℃～1600℃,气体压力为019MPa,气体介质流量为6m3/min,金属液流量为42g/s,盐流量为58g/s条件下,制备出平均粒径为20μm和球形度良好的不锈钢粉末。

A novel gas and solid dual-phase atomization technology with solid salt (NaCl) particles was used to fabricate the stainless steel powders. The effects of the liquid metal flow rate, the solid medium mass flow rate, the gas medium mass flow rate and gas pressure on granularity and morphology of the as-prepared stainless steel powders were discussed. The results show that the finer stainless steel powders with higher sphericity are produced by the gas and solid dual-phase atomization than those produced by the conventional gas atomization technology under the same gas pressure and flowing rate. The stainless steel powder becomes finer and the size distribution is narrower with the mass flow rate and pressure of gas medium increasing. With the increase of the solid medium mass flow rate, the mean size of the as-atomized stainless steel powder tends to decrease firstly and then increase. When the liquid metal temperature is( 1550)(1600℃,) the pressure of gas with flow rate of 6m^3/min is 0.9MPa, the molten metal flow rate is 42g/s and the salt flow rate is 58g/s, the smooth and spherical stainless steel powders with the grain size of 20μm are prepared.