喷丸处理对锆合金微动磨损及抗腐蚀性能的影响

Effect of Shot Peening on Fretting Wear and Corrosion Resistance of Zirconium Alloy

目的探索喷丸处理工艺对锆合金包壳管的微动磨损及抗腐蚀性能的影响。方法对锆合金包壳管进行喷丸处理,对原始试样及喷丸处理试样进行微动磨损试验,并测量磨损深度和磨损体积、表征微动磨损后的表面粗糙度和表面形貌。此外,对原始试样及喷丸处理试样进行腐蚀试验,测量喷丸前后锆合金的腐蚀增重。结果喷丸处理使ZIRLO锆合金的磨损体积相对于未处理试样减少了5.7%。喷丸处理能够提高ZIRLO锆合金包壳管的硬度,但是高硬度区域较薄,约为4~8μm。腐蚀介质为去离子水和Li OH溶液时,喷丸试样的腐蚀增重分别经过140 d和220 d后低于原始试样。Li OH溶液条件下,未喷丸的ZIRLO合金管氧化膜的厚度约为15μm,喷丸后ZIRLO合金管氧化膜的厚度约为1.21μm。结论喷丸处理在一定程度上可以提高ZIRLO锆合金抗微动磨损性能和抗腐蚀性能,其中抗微动磨损性能有提高,但幅度不大,这与硬化层较薄有关。喷丸后试样经过腐蚀试验,腐蚀增重减少,氧化膜厚度减小,说明抗腐蚀性能增强,但喷丸试样的抗腐蚀性能在腐蚀进行到一定阶段时才开始体现。

The work aims to study the influence of shot peening on fretting wear and corrosion resistance of zirconium alloy cladding tube.Shot peening was carried out to zirconium alloy cladding tube.Fretting wear tests were performed on the untreated and shot peened specimens.The wear depth and wear volume were measured.Meanwhile,the surface roughness and surface topography were characterized.Then,corrosion tests were conducted to the untreated and shot peened specimens and the corrosion gain before and after shot peening was measured.The wear volume of shot peened zirconium alloy was reduced by 5.7%compared to untreated specimens.Shot peening could improve the hardness of the zirconium alloy cladding tube.However,the thickness of the high hardness area was thinner,which was only about 4~8μm.When the medium of corrosion tests was deionized water and LiOH solution,the corrosion gain curves of shot peened specimens were lower than that of untreated specimens after 140 and 220 days,respectively.The thickness of oxide film of ZIRLO alloy without and with shot peening was about 15μm and 1.21μm in LiOH solution.Shot peening can improve the resistance of fretting wear and corrosion damage of ZIRLO alloy to some extent.The increased range of fretting wear resistance is small because of the thin hardening layer.Moreover,the corrosion gain and oxide film of shot peened specimens decrease,showing improvement of corrosion resistance,but the corrosion resistance by shot peening is only reflected after a certain stage.