Structural and Magnetic Properties of Duplex Stainless steel (UNS S31803) Powders Obtained by high Energy Milling of Chips with Additions of NbC

In this study, the high energy mechanical milling was utilized to the production of duplex stainless steel powders from the recycling chips with and without the addition niobium carbide. The effect of milling time and addition carbide on the morphology, particle size and magnetic properties of the powders was investigated. The utilization of the powder metallurgy constitute an important alternative for the reuse of waste in the industrial sector. The milling was realized using a planetary ball mill for 20 hours at a milling speed of 350 rpm and ball-to-powder weight ratio of 15:1were used, and the (0% and 3 wt. %) niobium carbide (NbC) addition. Scanning electron microscopy and particle distribution analysis were used for characterization of morphology and measure of particle size. Also, to analyze the transformations of phases were investigated using the magnetic characterization and x-ray diffraction. The results indicated that the addition of niobium carbide results in the reduction of the particle size of steel of the order of 20%, besides the reduces the transformation of austenite into strain induced martensitic phase.

本研究采用高能机械球磨工艺，以回收不锈钢切屑为原料，分别添加与不添加碳化铌（NbC），制备双相不锈钢粉末。本研究考察了球磨时间与碳化铌添加量对粉末形貌、粒径及磁性能的影响。粉末冶金技术为工业领域的废弃物资源化再利用提供了重要的替代方案。本次实验采用行星式球磨机，以15:1的球料质量比、350转每分钟的转速球磨20小时，分别添加0 wt.%与3 wt.%的碳化铌（NbC）。采用扫描电子显微镜与粒径分布分析对粉末形貌与粒径进行表征；同时通过磁性能测试与X射线衍射（X-ray diffraction）分析物相转变过程。结果表明，添加碳化铌可使钢粉末的粒径降低约20%，同时抑制奥氏体向应变诱导马氏体相的转变。