雾化法制备25Cr35NiNb合金粉末性能研究  

Study on properties of 25Cr35NiNb pre-alloyed powder prepared by atomization

作　　者：李继展 范志超 向抒林 LI Jizhan;FAN Zhichao;XIANG Shulin(Hefei General Machinery Research Institute Co.,LTD,National Technology Research Centre on Pressure Vessel and Pipeline Safety Engineering,Hefei 230031,China;Special Equipment Inspection Station of Hefei General Machinery Research Institute Co.,LTD,Hefei 230031,China)

机构地区：[1]合肥通用机械研究院有限公司国家压力容器与管道安全工程技术研究中心,安徽合肥230031 [2]合肥通用机械研究院特种设备检验站有限公司,安徽合肥230031

出　　处：《粉末冶金工业》2023年第5期10-16,共7页Powder Metallurgy Industry

基　　金：国家自然科学基金资助项目(51901064);安徽省重点研究与开发计划资助项目(202104a05020023);安徽省自然科学基金资助项目(2018085ME146);合肥通用机械研究院有限公司博士科技基金资助项目(2020011740)。

摘　　要：采用真空气雾化(VGA)和等离子旋转电极雾化(PREP)两种方法分别制备了粒径为53~150μm的25Cr35NiNb合金粉末,使用OM、SEM、XRD、激光粒度分析仪、霍尔流速计、松装密度计、ICP光谱仪、氧氮氢分析仪、碳硫测定仪等对两种粉末进行了系统的检测,对比研究两种雾化法制备粉末的性能,以及激光定向能量沉积件的物理性能。结果表明,两种粉末内部均为非平衡凝固形成的单相奥氏体柱状晶组织,VGA粉末(9.38%)的孔隙率明显高于PREP粉末(2.94%);VGA粉末的球形度明显低于PREP粉末,导致其流动性相对较差(VGA:16.04 s/50g,PREP:13.80 s/50g),松装和振实密度相对较低(VGA:4.41 g/cm^(3)和5.06 g/cm^(3),PREP:4.64 g/cm^(3)和5.31 g/cm^(3));而且PREP粉末的粒径分布更窄,氧和氮的含量也更低。因此,PREP粉末激光定向能量沉积件的致密度和高温持久性能明显更优。25Cr35NiNb pre-alloyed powder with the particle size ranging from 53μm to 150μm was prepared by vaccum gas atomization(VGA)and plasma rotating electrode process(PREP),respectively.Properties of two kinds of powder were systematically analyzed using optical microscope,scanning electron microscopy,X-ray diffraction,laser particle size analyzer,Hall current meter,loose densitometer,inductively coupled plasma spectrometer,oxygen-nitrogen-hydrogen analyzer and carbon-sulfur determinator.Meanwhile,physical properties of deposits fabricated by laser direct energy deposition with VGA and PREP powders were also investigated in detail.The results show that microstructures of VGA and PREP powders are basically single-phase austenite columnar crystals due to the rapid cooling of non-equilibrium solidification.The porosity of VGA powder(9.38%)is much more than that of PREP powder(2.94%).The sphericity of VGA powder is obviously inferior to that of PREP powder.In terms of VGA powder compared with PREP powder,the flowability is worse(the Hall velocity of VGA and PREP powders are 16.04 s/50g and 13.80 s/50g),the apparent or tap density is also lower(the apparent density of VGA and PREP powders is 4.41 g/cm~3 and 4.64 g/cm~3,the tap density of VGA and PREP powders is5.06 g/cm~3 and 5.31 g/cm~3),the particle size distribution is wider and the content of oxygen and nitrogen are higher.Therefore,density and stress-rupture properties of the deposit fabricated by laser direct energy deposition with PREP powder are clearly superior to that with VGA powder.

关 键 词：25Cr35NiNb合金粉末 等离子旋转电极雾化 真空气雾化 激光定向能量沉积 致密度 高温持久性能 

分 类 号：TF123.112[冶金工程—粉末冶金]