超音速气雾化制备316L不锈钢粉末的表征  

Characterization of 316 L stainless steel powders produced by supersonic gas atomization

作　　者：赵新明[1] 徐骏[1,2] 朱学新[1] 张少明[1] 朱盼星[1] 

机构地区：[1]北京有色金属研究总院国家有色金属复合材料工程技术研究中心,北京100088 [2]北京康普锡威焊料有限公司,北京100088

出　　处：《北京科技大学学报》2009年第10期1270-1276,共7页Journal of University of Science and Technology Beijing

基　　金：科技部科研院所技术开发研究专项基金资助项目(No.NCSTE-2007-JKZX-054)

摘　　要：利用自行研制的超音速雾化技术制备了316L不锈钢粉末,采用激光粒度仪、扫描电镜、金相显微镜和X射线衍射仪进行了表征.结果表明,316L不锈钢粉末的平均粒度约为24μm,粒度分布的几何标准偏差δ为1.75;粉末内部存在三种典型凝固组织,即具有发达二次枝晶的枝晶组织、胞晶组织以及枝状晶与胞状晶的混合组织;大粒径气雾化316L不锈钢粉末为单一的γ奥氏体相,小粒径粉末由γ奥氏体相+少量δ铁素体相共同组成;熔滴的冷速随着粒径的减小而提高,平均冷却速率为104～107K.s-1.316 L stainless steel powders were prepared by supersonic gas atomization.The characteristic of the powder particles was investigated by means of laser particle size analyzer,scanning electron microscopy（SEM）,optical microscopy（OM）and X-ray diffraction（XRD）technique.The result indicates that the mass median particle diameter is about 24 μm and the geometric standard deviation δ is 1.75.Three main types of solidification microstructures were observed in the powders：well-developed dendrite,cellular and a mixture of dendrite and cellular.XRD measurements show that γ-austenite phase is found in the big particle while small particle is a composite consisting of δ-ferrite and γ-austenite phases.The cooling rate is inversely related to the particle size,i.e.,it increases with decreasing particle size.The mean cooling rates of melt droplets range from 104 to 10^7 K·s^-1.

关 键 词：不锈钢粉末 气雾化 凝固组织 金属注射成形 

分 类 号：TF123.2[冶金工程—粉末冶金]