Zr-0.8Sn-0.4Nb-0.4Fe-0.1Cr-xCu合金在360℃ LiOH水溶液中的耐腐蚀性能

Corrosion resistance of Zr-0. 8Sn-0. 4Nb-0. 4Fe-0. 1Cr-xCu alloys in LiOH aqueous solution at 360 ℃

采用静态高压釜腐蚀试验研究了在S5（Zr-0.8Sn-0.4Nb-0.4Fe-0.1Cr）锆合金基础上添加Cu的S5＋x Cu（x=0~0.5,质量分数,%）合金在360℃/18.6 MPa/0.01 M LiOH水溶液中的耐腐蚀性能,用TEM和SEM分别观察了合金和氧化膜的显微组织。结果表明,在S5合金中添加Cu对其在360℃/18.6 MPa/0.01 M LiOH水溶液中的耐腐蚀性能是有害的,特别是当S5合金中添加的Cu含量超过0.2%时,合金在360℃/18.6 MPa/0.01 M LiOH水溶液中的耐腐蚀性能会随Cu含量的增加而急剧恶化,这主要是因为此时合金中含有富铜的Zr_2Cu型相析出,这种Zr_2Cu型相对锆合金在360℃/18.6 MPa/0.01 M LiOH水溶液中的耐腐蚀性能非常有害。

The effect of addition Cu （ x = 0 - 0.5, mass fraction, % ） on corrosion resistance of S5 （ Zr-0.80Sn-0.4Nb-O. 4Fe-0. 10Cr） alloy was investigated in 0. 01M LiOH aqueous solution at 360℃ and 18.6 MPa by autoclave tests. The microstructure of the alloys and the oxide films on the corroded specimens were observed by TEM and SEM, respectively. The results show that the addition of Cu is harmful to the corrosion resistance of the S5 alloy in 0. 01M LiOH aqueous solution at 360 ℃ and 18.6 MPa. Especially when the addition of Cu content is above 0.2% , the corrosion resistance of the S5 ＋ xCu alloys will become worse sharply with the increase of Cu content. The second phase particles （SPPs） of Zr2Cu appear when the addition of Cu is above 0.2% , which is harmful to the corrosion resistance of the $5 ＋xCu alloys in 0.01M LiOH aqueous solution at 360 ℃ and 18.6 MPa.