稀土元素对气雾化高强不锈钢粉末性能的影响  

Effect of rare earth elements on properties of atomized high strength stainless steel powder

作　　者：刘畅[1,2] 张梦醒 刘雨 梁剑雄[1] 杨志勇[1] 褚韦涵[1] 王长军 LIU Chang;ZHANG Mengxing;LIU Yu;LIANG Jianxiong;YANG Zhiyong;CHU Weihan;WANG Changjun(Research Institute of Special Steels,Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China;Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]钢铁研究总院有限公司特殊钢研究院,北京100081 [2]北京科技大学新材料技术研究院,北京100083

出　　处：《钢铁》2024年第6期180-188,197,共10页Iron and Steel

基　　金：科技部重点研发资助项目(2021YFB3702501)。

摘　　要：通过增材制造技术成形高强不锈钢可以有效提高不锈钢材料的成形效率、减少原料浪费、适用于各类复杂形状制件,是未来高强不锈钢成形的重要方式。但是气雾化法制备得到的不锈钢粉末存在细粉收得率低、卫星粉含量高、杂质氧含量高等问题,严重影响了通过增材制造技术成形的高强不锈钢零件的致密度、力学性能等特性。为了提高零件的成形质量,需要对气雾化金属粉末进行有效地改性,减少粉末表面卫星粉、提高粉末流动性。制备了PH13-8Mo高强不锈钢粉末,并在气雾化制粉时向其中加入稀土La元素,后续的表征结果表明不锈钢粉末的颗粒形状、球形度和粉末流动性等粉末物性都在加入稀土后得到了改善。为了系统探究稀土元素的影响规律,制备了3批不同成分的含稀土粉末,稀土La的质量分数分别为0.11%、0.39%、0.59%。采用SEM、XPS、EPMA、3DAPT等分析手段,表征粉末形貌、粒度分布、流动性、相组成、化学成分等特性。结果表明,添加了稀土的PH13-8Mo不锈钢粉末各项物性都明显改善、粉末球形度增加、流动性明显提高,稀土加入对PH13-8Mo不锈钢的相转变温度和组织形貌也存在影响。通过对粉末成分的表征发现稀土元素在粉末颗粒中沿晶界分布,存在明显的偏析情况。研究结果证实了在气雾化制粉过程中向高强不锈钢中添加稀土元素来调控粉末物性,是一种高效可行的工艺路线。Forming high-strength stainless steel through additive manufacturing can effectively improve the forming efficiency of stainless steel materials,reduce raw material waste,and be suitable for various complex shaped parts.It is an important way for the future forming of high-strength stainless steel.However,the stainless steel powder prepared by atomization method has problems such as low fine powder yield,high satellite powder content,and high impurity oxygen content,which seriously affect the performance of selected laser melting formed parts.In order to ensure the forming quality of high-strength stainless steel parts melted by selective laser,it is necessary to effectively modify the atomized metal powder,reduce powder satellite powder,and improve powder flowability.PH13-8Mo stainless steel powder was prepared by vacuum atomization method,and rare earth La was added into the powder to improve the morphology,sphericity and fluidity of the powder,so that it can basically meet the requirements of 3D printing process.The mass fraction of La was 0.11%,0.39%and 0.59%respectively.The surface morphology,particle size distribution,fluidity,phase composition and chemical composition of the powders were characterized by SEM,XPS,EPMA and 3DAPT.The results show that the physical properties of PH13-8Mo stainless steel powder with rare earth addition are obviously improved,the sphericity and fluidity of the powder are increased,and the addition of rare earth also has an effect on the phase transition temperature and microstructure of PH13-8Mo stainless steel.Through the characterization of the powder composition,it is found that the rare earth elements are distributed along the grain boundary in the powder particles,and there is obvious segregation.At the same time,the feasibility of adding rare earth elements to the stainless steel by the process of atomization was also confirmed.

关 键 词：不锈钢粉末 气雾化 粉末改性 粉末流动性 元素分布表征 

分 类 号：TG142.71[一般工业技术—材料科学与工程]