In Situ Observation of Solidification Process of AISI 304 Austenitic Stainless Steel

The solidification process of AISI 304 stainless steel during cooling at a rate of 0.05 K/s has been observed in situ using a confocal scanning laser microscope （CSLM）. The results show that the 8 phase appeared first in liquid steel, as the temperature decreased, the γ phase precipitated prior at δ-grain boundary at 1452. 2 ℃, the liquid steel disappeared at 1 431.3 ℃, and then the γ phase precipitated on the δ ferrite. Based on the Scheil-Gulliver solidification model, the solidification processes of AISI 304 stainless steel are simulated using the Scheil model in Thermo Calc, and the simulation results agree well with the results observed in the experiment.     

钕铁硼合金速凝薄带的微观结构

本文就采取速凝工艺制作的钕铁硼薄带中影响磁体性能的微观结构进行了研究。速凝薄带工艺可以得到较传统浇铸工艺更加精细的微观结构,母合金中基本消除了α－Fe。快速定向凝固得到了排列整齐的钕铁硼主相的片关晶结构,同时在贴辊面存在小于3μm的疏松的碎晶。氢破碎是速凝带思想的破碎方法。