Microstructures and corrosion resistance of Zircaloy-4 after surface alloying with copper by high-current pulsed electron beam
Abstract
In present paper, Zircaloy-4 surface alloying with copper (Cu) using a high-current pulsed electron beam (HCPEB) device was firstly studied. For investigating the changes in microstructures and corrosion resistance prior and after surface alloying, a series of characterization methods were adopted. Results revealed that, after surface alloying by HCPEB, a Cu-riched alloying layer with a thickness of about 3 μm was formed within the melted layer, inside which martensitic transformation was largely inhibited and large numbers of ultra-fine equiaxed β grains were generated. Most of the Cu elements in the alloying layer were uniformly distributed in the β-Zr supersaturated solid solution, others were existed in the form of fine dispersed ZrCu SPPs. Besides, Zr(Fe,Cr)2 SPPs were dissolved into the Zr-matrix within the HCPEB affect area. Compared with initial and directly irradiated specimens, the specimen after surface alloying exhibited extremely excellent anti-corrosion performance at 500 °C/10.3 MPa superheated steam, which was mainly attributed to those supersaturated Cu elements.
- Publication:
-
Applied Surface Science
- Pub Date:
- January 2020
- DOI:
- 10.1016/j.apsusc.2019.144222
- Bibcode:
- 2020ApSS..50144222Y
- Keywords:
-
- Zircaloy-4;
- High-current pulsed electron beam (HCPEB);
- Alloying element Cu;
- Microstructure;
- Corrosion resistance