Alloy 690TT samples with four kinds of surface states were prepared: 1) ground to 400 grit; 2) ground to 1500 grit; 3) mechanically polished (MP) and 4) electro-polished (EP). The surface morphologies and the surface skin layers' microstructures of these samples were characterized systematically using various methods and the effects of surface states on the oxidation behaviours of Alloy 690TT were also discussed. The results showed that surface roughness and micro-hardness decreased gradually from the ground to EP surfaces. The grains in the near-surface layers of the ground and MP surfaces had been refined and the residual strains were also very high. The dislocations on the ground surfaces were mainly parallel dislocation lines. The thickness of the superficial cold-worked layers decreased gradually from the ground surfaces to polished surfaces. The oxide morphologies and oxidation rate depended greatly on the surface states of samples. Cold-working by grinding treatments could benefit the outward diffusion of metallic atoms and the nucleation of surface oxides and then accelerate the growth of surface oxide films.
参考文献
| [1] | S. Wang;Y. Takeda;K. Sakaguchi .Role of Work-Hardened Surface Layer in initiation of Environmentally Assisted Cracking in High-Temperature Water[J].Corrosion: The Journal of Science and Engineering,2006(8):651-656. |
| [2] | S. Wang;T. Shoji;N. Kawaguchi .Initiation of Environmentally Assisted Cracking in High-Temperature Water[J].Corrosion: The Journal of Science and Engineering,2005(2):137-144. |
| [3] | F. Scenini;R.C. Newman;R.A. Cottis .Effect of Surface Preparation on Intergranular Stress Corrosion Cracking of Alloy 600 in Hydrogenated Steam[J].Corrosion: The Journal of Science and Engineering,2008(11):824-835. |
| [4] | L. Tan;X. Ren;K. Sridharan;T.R. Allen .Effect of shot-peening on the oxidation of alloy 800H exposed to supercritical water and cyclic oxidation[J].Corrosion Science: The Journal on Environmental Degradation of Materials and its Control,2008(7):2040-2046. |
| [5] | S. CARLSSON;P. -L. LARSSON .ON THE DETERMINATION OF RESIDUAL STRESS AND STRAIN FIELDS BY SHARP INDENTATION TESTING[J].Acta materialia,2001(12):2179-2191. |
| [6] | N. R. Tao;Z. B. Wang;W. P. Tong;M. L. Sui;J. Lu;K. Lu .An investigation of surface nanocrystallization mechanism in Fe induced by surface mechanical attrition treatment[J].Acta materialia,2002(18):4603-4616. |
| [7] | W. Li;D.Y. Li .Influence of surface morphology on corrosion and electronic behavior[J].Acta materialia,2006(2):445-452. |
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