Ag对抗菌不锈钢组织性能的影响及其析出行为

在304L不锈钢的成分基础上,添加不同质量分数(0.072%~0.132%)的Ag,并对其热轧板进行固溶处理和冷轧,发现材料的显微组织均为均匀的奥氏体组织,且随着Ag含量的增加,屈服强度及伸长率变化均不明显。利用OM、SEM和TEM观察不同变形条件下材料中Ag颗粒变化,发现Ag颗粒主要为材料冶炼时未熔入到基体内的Ag,其在基体中弥散分布,呈椭球形或球形;Ag颗粒有2种存在形式,即几纳米到几十纳米的富Ag相、由多个纳米级Ag相团簇聚集在一起形成的几百纳米到几微米的Ag颗粒聚集物。另外,热轧后,富Ag颗粒聚集物沿轧制方向变成带状、棒状,部分分裂为椭球状或球状;进一步冷轧变形后,富Ag颗粒的尺寸减小,且变形量越大,Ag颗粒尺寸越小。

Effects of Ag on microstructure and properties and its precipitation behavior in antibacterial stainless steel

Based on the chemical composition of 304L stainless steel, different mass fractions of Ag (0.072%-0.132%) were added in the steel. The experimental steels were successively hot-rolled, solution heat treatment and cold-rolled, and their microstructures were uniformly distributed austenite. The yield strength and elongation did not change obviously with the increase of Ag content. The Ag-containing phase was observed and comparatively analyzed under different deformation conditions using optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the Ag-containing phase is mainly composed of Ag that not melt into the matrix during smelting, and they are distributed evenly in the matrix, showing ellipsoid or spherical shape. There are two forms of Ag in the matrix, one is Ag-rich phases from several nanometers to tens of nanometers, and the other is Ag-particle aggregates of several hundred nanometers to several microns formed by multiple nanoscale Ag phase clusters. After hot-rolling, Ag-rich phases become banded and rod-shaped along the rolling direction, and some of them split into elliptic or spherical shape. After further cold rolling, the size of Ag-rich phases decreas with increase of the deformation.