安茂忠
,
杨哲龙
,
张景双
,
屠振密
中国腐蚀与防护学报
防护性锌基合金(Zn-Ni、Zn-Fe、Zn-Co)镀层钝化膜的耐蚀性比锌镀层钝化膜提高2～4倍。XPS及AES分析表明,合金镀层钝化膜与锌镀层钝化膜均由CrO_3、Cr_2O_3、Zn(OH)_2、ZnO及H_2O等组成,并且CrO_3/Cr_2O_3的相对含量和Zn(OH)_2/ZnO的相对含量也基本相同。它们的区别在于:合金镀层钝化膜中总铬量较高,膜层完整、致密,镀层/钝化膜界面存在铁系金属的富集层,这是锌基合金镀层钝化膜具有高耐蚀性的主要原因。
关键词:
锌基合金
,
Electroplating
,
Corrosion resistance
,
Passivation
B.X. Zhou
,
M.Y. Yao
,
Z.K. Li
,
X.M. Wang
,
J. Zhou
,
C.S. Long
,
Q. Liu
材料科学技术（英文）
In order to optimize the microstructure and composition of N18 zirconium alloy (Zr–1Sn–0.35Nb–0.35Fe–0.1Cr, in mass fraction, %), which was developed in China in 1990s, the effect of microstructure and composition variation on the corrosion resistance of the N18 alloy has been investigated. The autoclave corrosion tests were carried out in super heated steam at 400 °C/10.3 MPa, in deionized water or lithiated water with 0.01 mol/L LiOH at 360 °C/18.6 MPa. The exposure time lasted for 300–550 days according to the test temperature. The results show that the microstructure with a fine and uniform distribution of second phase particles (SPPs), and the decrease of Sn content from 1% (in mass fraction, the same as follows) to 0.8% are of benefit to improving the corrosion resistance; It is detrimental to the corrosion resistance if no Cr addition. The addition of Nb content with upper limit (0.35%) is beneficial to improving the corrosion resistance. The addition of Cu less than 0.1% shows no remarkable influence upon the corrosion resistance for N18 alloy. Comparing the corrosion resistance of the optimized N18 with other commercial zirconium alloys, such as Zircaloy-4, ZIRLO, E635 and E110, the former shows superior corrosion resistance in all autoclave testing conditions mentioned above. Although the data of the corrosion resistance as fuel cladding for high burn-up has not been obtained yet, it is believed that the optimized N18 alloy is promising for the candidate of fuel cladding materials as high burn-up fuel assemblies. Based on the theory that the microstructural evolution of oxide layer during corrosion process will affect the corrosion resistance of zirconium alloys, the improvement of corrosion resistance of the N18 alloy by obtaining the microstructure with nano-size and uniform distribution of SPPs, and by decreasing the content of Sn and maintaining the content of Cr is discussed.
关键词:
Zirconium alloys
,
null
,
null
,
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