应变速率对TC4-0.55%Fe合金在模拟海水中应力腐蚀行为的影响  

Effect of Strain Rate on Stress Corrosion Cracking of TC4-0.55%Fe Alloy in Simulated Seawater Solution

作　　者：段薇薇 淡振华 常辉[1] 师红旗[1] 朱晓弦 李广州 谷元玉 周廉[1] DUAN Weiwei;DAN Zhenhua;CHANG Hui;SHI Hongqi;ZHU Xiaoxian;LI Guangzhou;GU Yuanyu;Zhou Lian(Tech Institute of New Materials ＆ College of Materials Science and Technology,Nanjing Tech University,Nanjing 210009,China)

机构地区：[1]南京工业大学新材料研究院&材料科学与工程学院,南京210009

出　　处：《腐蚀与防护》2018年第9期689-693,697,共6页Corrosion & Protection

摘　　要：通过电化学测试、慢应变速率拉伸试验(SSRT)并结合扫描电镜(SEM)分析了TC4-0.55%Fe合金在模拟海水中的应力腐蚀开裂(SCC)行为,揭示了应变速率(3.3×10^(-6) s^(-1)~10.0×10^(-6) s^(-1))对合金SCC行为的影响。结果表明:合金在模拟海水中具有应力腐蚀开裂敏感性;当应变速率为5.0×10^(-6) s^(-1)时,合金在模拟海水中的断口中心区域形貌以细小扁平韧窝为主,塑形变形不充分,呈现出脆性特征,表现出最高的应力腐蚀敏感性。当应变速率大于6.6×10^(-6) s^(-1)时,合金的断口由小而浅的韧窝向大而深的韧窝过渡,由此说明,高应变速率下,拉应力作用使试样迅速断裂,合金应力腐蚀敏感性较小,断口处有明显韧窝,表现出典型的韧性断裂特征。The stress corrosion cracking（SCC）performance of TC4-0.55%Fe alloy in simulated seawater solution was investigated by electrochemical measurements,slow strain rate test（SSRT）and scanning electron microscopy（SEM）.The effect of strain rate（changed from 3.3×10^-6 s^-1-10.0×10^-6 s^-1）on SCC behavior of the alloy was revealed.The results showed that TC4-0.55%Fe alloy possessed the maximum SCC susceptibility at the strain rate of 5.0×10^-6 s^-1 in the simulated seawater solution,the fracture surface was dominated by flattened dimples,with obvious tearing edges between the dimples,and the quasi-cleavage fracture surface appeared in the middle region of the fracture.When the strain rate was higher than 6.6×10^-6 s^-1,the fracture surface was changed from small and shallow dimples to large and deep dimples.Therefore,tensile stress made the specimen fractured rapidly at high strain rates,and the SCC susceptibility of the alloy was very small,its fracture showed typical ductile fracture with appreciable dimples.

关 键 词：TC4-0.55%Fe合金 应力腐蚀开裂(SCC) 慢应变速率试验(SSRT) 应变速率 

分 类 号：TG146.23[一般工业技术—材料科学与工程]