Cr对Zr-0.3Nb合金显微组织及在400℃/10.3 MPa过热蒸汽中腐蚀行为的影响  

Effect of Cr Addition on Microstructure and Corrosion Behavior of Zr-0.3Nb Alloy in 400℃/10.3 MPa Superheated Steam

作　　者：张弛 范周洋[1,2] 林晓冬 彭丽婷 梁雪 李毅丰[1,2] 陈文霞 彭剑超 李强[2] Zhang Chi;Fan Zhouyang;Lin Xiaodong;Peng Liting;Liang Xue;Li Yifeng;Chen Wenxia;Peng Jianchao;Li Qiang(Institute of Materials,Shanghai University,Shanghai 200072,China;Laboratory for Microstructures,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料研究所,上海200072 [2]上海大学微结构重点实验室,上海200444

出　　处：《稀有金属材料与工程》2023年第5期1915-1924,共10页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52001192,51901123)。

摘　　要：通过制备Zr-0.3Nb-xCr(x=0.2,0.5,1.0,%,质量分数)合金,并在高压釜中进行400℃/10.3 MPa过热蒸汽腐蚀实验,利用SEM和TEM表征和分析合金基体及氧化膜截面显微组织,研究了Cr对Zr-0.3Nb合金显微组织及在400℃/10.3MPa过热蒸汽中腐蚀行为的影响。结果表明,Zr-0.3Nb-xCr合金中的第二相主要为面心立方和密排六方的ZrCr_(2)相,尺寸在10~100 nm范围内,随Cr含量增加,第二相的数量增加,但尺寸无明显变化。添加适量的Cr能促进氧化膜中柱状晶的生长并延缓柱状晶向等轴晶的转变,从而改善Zr-0.3Nb合金的耐腐蚀性能。当Zr-0.3Nb合金中添加0.5%的Cr时,耐腐蚀性能较好,这可能是因为Zr-0.3Nb-0.5Cr合金的氧化膜较为致密,且在氧化膜/基体界面处存在亚氧化层,可以延缓氧化膜的显微组织演化,提高合金的耐腐蚀性能。Zr-0.3Nb-xCr(x=0.2,0.5,1.0,wt%)alloys were prepared and then corroded in 400℃/10.3 MPa superheated steam in an autoclave.The microstructures of the alloy matrix and oxide film were characterized using SEM and TEM in order to investigate the effect of Cr on the microstructure and corrosion behavior of Zr-0.3Nb alloy.Results show that the second phase particles in the Zr-0.3Nb-xCr alloys are face centered cubic and hexagonal close-packed ZrCr_(2) phase with a size in a range of 10~100 nm.With increasing the Cr content,the size of second phase particles is nearly unchanged,but their number is increased.Appropriate Cr addition to the Zr-0.3Nb alloy could promote the growth of columnar crystals in the oxide film and delay the transformation from columnar crystals to equiaxed crystals,thereby improving the corrosion resistance of the Zr-0.3Nb alloy.The corrosion resistance is relatively better when 0.5wt%Cr is added to the Zr-0.3Nb alloy.This may be due to the compact oxide film and the presence of a sub-oxide layer at the oxide/metal interface,which could delay the microstructure evolution of the oxide film and thus improve the corrosion resistance of the Zr-0.3Nb-0.5Cr alloy.

关 键 词：锆合金 Cr添加 过热蒸汽腐蚀 氧化膜 显微组织 

分 类 号：TG146.414[一般工业技术—材料科学与工程]