AISI304表面Fe_3Si型过渡金属硅化物渗层结构缺陷初探

Study of Structure Defect in Fe_3Si Type Silicide Layer Deposited on AISI 304 Stainless Steel

利用NaCl∶KCl∶NaF=2∶2∶1(摩尔比)的碱金属卤化物混合体系为载体,Na2SiF6∶Si=8∶2粉末为渗硅剂,SiO2为助渗剂,800℃下渗硅5 h可实现在AISI 304不锈钢表面形成Fe3Si型硅化物渗层.采用万能材料试验机进行轴向拉伸试验,用附带能量色散谱仪的扫描电子显微镜进行断面分析.结果表明,渗层中的大空洞为包盐孔洞.

FeaSi type silicide layer on AISI 304 stainless steel were formed in molten salts at 800℃ for 5h by u- sing molten mixture of NaESiF6 ：Si = 8：2 as siliconizing agent and the molten halogenide of alkali metals of NaCI： KCI ： NaF = 2 ： 2 ： 1 as siliconizing agent carrier by adding SiO2 as another source. The tension behavior of the samples was tested on an universal tension apparatus. Meanwhile, the analysis of cross section of the silicide lay- er were studied by scanning electron microscope （SEM） attached with energy dispersive X-ray spectrometer （EDS）. The results show that the composition in the holes of the silicide layer is salt.