采用慢应变速率拉伸(SSRT)技术测试了LC4铝合金在空气和质量分数为3.5％的NaCl溶液中的应力腐蚀断裂(SCC)行为．研究了应变速率对铝合金SCC行为的影响和氢在LC4高强铝合金应力腐蚀断裂过程中的作用．试验结果表明，LC4合金具有SCC敏感性，在潮湿空气中发生应力腐蚀断裂，而在干燥空气中不发生应力腐蚀断裂．对于长横取向的LC4铝合金试样，在应变速率为1.331×10-6 s-1时，其SCC敏感性比应变速率为6.655×10-6s-1时的敏感性大．在潮湿空气和阳极极化条件下，铝合金的应力腐蚀断裂机理是以阳极溶解为主，氢几乎不起作用．在预渗氢或阴极极化条件下，氢脆起主要作用，预渗氢时间延长可加速LC4合金的应力腐蚀断裂．
The stress corrosion cracking (SCC) behavior of aluminum alloy 7075 in air and in 3.5wt% NaClwater solution has been tested using slow strain rate tension (SSRT) technique, and the effect of strain rateand hydrogen on the SCC behavior of the alloy has been studied. The experimental results show that the alloyis susceptible to SCC which can occur in humid air but can′t in dry air. Alloy 7075 with L-T direction is moresusceptible to SCC at a strain rate of 1. 331 × 10-6 s-1 than at that of 6. 655 × 10-6 s-1. In humid air, or by anod-ic polarization in 3.5wt% NaCl water solution, the mechanism of SCC is mainly anodic dissolution. Under thecondition of hydrogen pre-permeation or cathodic polarization, hydrogen embrittlement plays a key role duringthe SCC process. The results also indicate that the SCC resistance of ahoy 7075 decreases with increasing thetime of hydrogen pre-permeation.
参考文献
| [1] | Joyce M R;SYNGELLAKIS S;REED P A S.Microstructural influences on fatigue crack irritation and early growth behaviour in plain bearing Al-based linings[A].Switzerland:2000 Trans Tech Publications,2000:1445-1450. |
| [2] | NADKANI V S;SHARMA M C.Fatigue and heat transfer behaviour of shot penned aluminum alloy for automobile applications[A].Switzerland:2000 Trans Tech Publications,2000:1537-1542. |
| [3] | Speidel M O.The theory of stress corrosion cracking in alloys[M].Boston: NATO,1971 |
| [4] | PATHANIA R S;TROMANS D .Initiation of stress corrosion cracks in aluminum alloys[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1981,12(04):607-612. |
| [5] | Albrecht J;THOMPSON A W;BERNSTEIN I M .The role of microstructure in hydrogen-assisted fracture of 7075 aluminum alloy[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1979,10(11):1759-1766. |
| [6] | Scamans G M .Evidence for crack-arrest markings on intergranular stress corrosion fracture surfaces in Al-Zn-Mg alloys[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1980,11(05):846-850. |
| [7] | HOLROYD N J H;HARDIE D .The effect of microstructure on the hydrogen embrittlement of aluminum alloys[J].Corrosion Science,1981,21(01):129-134. |
| [8] | Albrecht J;BERNSTEIN I M;THOMPSON A W .Evidence for dislocation transport of hydrogen in aluminum[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1982,13(05):811-820. |
| [9] | HARDWICK D A;THOMPSON A W;BERNSTEIN IM .The effect of copper content and microstructrue on the hydrogen embrittlement of Al-6Zn-2Mg alloys[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1983,14(12):2517-2526. |
| [10] | HARDWICK D A;THOMPSON A W;BERNSTEIN IM .The effect of copper content and micrestructrue on the hydrogen embrittlement of 7050-type alloys[J].Corrosion Science,1988,28(12):1127-1137. |
| [11] | Lee Seong-Min;PYUN SU-Ⅱ;CHUN YOUNGGAB .A critical evaluation of the stress-corrosion cracking mechanism in high-strength aluminum alloys[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1991,22(10):2407-2414. |
| [12] | NAJJAR D;MAGNIN T;WARNER .Influence of critical surface defects and localized competition between anodic dissolution and hydrogen effects during stress cormsion cracking of a 7050 aluminum alloy[J].Materials Science and Engineering A,1997,238:293-302. |
| [13] | Scully J R;YOUNG JR G A;SMITH S W.Hydrogen solubility diffusion and trapping in high purity aluminum and selected Al-base alloys[A].Switzerland:2000 Trans Tech Publications,2000:1583-1600. |
| [14] | STANZL S E;MAYER H R;TSCHEGG E K .The infiuence of air humidity on near-threshold fatigue crack growth of 2024-T3 aluminum alloy[J].Materials Science and Engineering A,1991,147:45-54. |
| [15] | Sieradzki K;FRIEDEERSDORF F J .Notes on the surface mobility mechanism of stress-corrosion cracking[J].Corrosion Science,1994,36(04):669-675. |
| [16] | PREET M SINGH;JOHN J LEWANDOWSKI .Effects of treatment on stress corrosion cracking of a discontinuously reinforced aluminum (DRA) 7xxx alloy during slow strain rate testing[J].Scripta Metallurgica et Materialia,1995,33(09):1393-1399. |
| [17] | 乔利杰;王燕斌;楮武扬.应力腐蚀机理[M].北京:科学出版社,1993 |
| [18] | Tsai W-T;DUH J-B;LEE J-J et al.Effect of pH on stress corrosion cracking of 7050-T7451 aluminum ailoy in 3.5wt% NaC1 solusion[J].Corrosion,1990,46(06):444-449. |
| [19] | WEIR P;PAO PS;HARTR G et al.Fracture mechanics and surface chemistry studies of fatigue crack growth in an aluminum alloy[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1980,11(01):151-158. |
| [20] | 肖纪美 .氢于材料[J].稀有金属,1985,4(02):2-18. |
| [21] | Speidel M O .Stress corrosion cracking of aluminum alloys[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1975,6(04):631-651. |
| [22] | Gasem Zuhair M;GANGLOFF RICHARD P.Effect of temper on environmental fatigue crack propagation in 7000-series aluminum alloys[A].Switzerland:2000 Trans Tech Publications,2000:1479-1488. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%