不锈钢粉尘碳热还原产物金属颗粒形貌和尺寸

为促进不锈钢粉尘资源化利用,本文提出碳热还原不锈钢粉尘制备高附加值球形超细金属粉末的新思路.为此,本文系统研究了1350℃下不锈钢粉尘碳热还原产物金属颗粒的微观结构、形貌和尺寸,以及配碳比对其的影响.配碳比从0.9经1.0增加到1.1时,还原失重率变化不明显,Fe-Cr-C金属颗粒球形度有轻微提高,金属颗粒尺寸显著细化...

Morphology and size of the metallic particles generated via carbothermic reduction of stainless steel dust

To promote the utilization of stainless steel dust as resource, a new concept that producing high added-value ultra-fine spherical metallic powders via carbothermic reduction of SSD is proposed in this paper. Therefore, the microstructure, morphology and size of metallic particles generated via carbothermic reduction of stainless steel dust at 1 350 ℃ as well as the effect of carbon addition ratio was studied in this paper. Increasing carbon addition ratio from 0.9 via 1.0 to 1.1, the weight loss due to reduction changes non-significantly, the sphericity of the metallic particles improves slightly, and the size of the metallic particles is refined first and then coarsened again. Coarse metallic particles(the diameter is approximately above 20 μm) contain both primary and secondary M7C3 carbide with poor sphericity and roundness. Fine metallic particles(the diameter is approximately below 20 μm) contain only secondary M7C3 carbide with relatively good sphericity and roundness. Thermodynamic calculation shows that precipitation of primary M7C3 carbide occurs once carbon content in the metallic particles exceeds 4.85%. The primary M7C3 carbide together with the residual slag after stainless steel dust reduction with high melting point and poor deformability deteriorates the sphericity and roundness of the metallic particles.