Diffusion behavior of Cr in gradient nanolaminated surface layer on an interstitial-free steel

被引：1

作者：

SLXie ^{[1
,2
]}

ZBWang ^{[1
]}

KLu ^{[1
]}

机构：

[1] Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences

[2] School of Materials Science and Engineering, University of Science and Technology of China

来源：

Journal of Materials Science & Technology | 2019年 / 35卷 / 03期

关键词：

Gradient nanolaminated structure; Interstitial-free steel; Diffusion; Low-angle grain boundary; Surface mechanical rolling treatment;

D O I：

暂无

中图分类号：

TG178 [各种金属及合金的腐蚀、防腐与表面处理];

学科分类号：

080503 ;

摘要：

Nanolaminated structures composed of low-angle grain boundaries(LAGBs) possess high thermal stability. In this paper, a gradient nanolaminated(GNL) surface layer with smooth finish was fabricated on an interstitial-free steel by means of surface mechanical rolling treatment. Microstructural observations demonstrated that the average lamellar thickness is about 80 nm in the topmost surface layer and increases with increasing depth. High thermal stability was confirmed in the GNL surface layer after annealing at 500℃. Diffusion measurements showed that effective diffusivity of Cr in GNL layer is 4–6 orders of magnitude higher than lattice diffusivity within the temperature range from 400 to 500℃. This might be attributed to numerous LAGBs or dislocation structures with a higher energy state in the GNL surface layer. This work demonstrates the possibility to advanced chromizing(or other surface alloying)processes of steels with formation of GNL surface layer, so that a thicker alloyed surface layer with a stable nanostructure is achieved.

引用

页码：460 / 464

页数：5