| 摘要: |
| 1998年1月，采用极化曲线、慢应变速率及扫描电镜等试验技术，研究了奥氏体不锈钢的应力腐蚀开裂。结果表明，奥氏体不锈钢在酸性氯离子溶液中处于活性阳极溶解状态，但却发生应力腐蚀开裂（SCC），其断口形貌具有解理特征。这种SCC无法用钝化膜破裂一再钝化理论和氢脆理论解释。本文以阳极溶解和形变的相互作用、激光散斑干涉术对裂纹尖端应变行为的测量、断口形貌观察等实验结果为基础，结合韧性和脆性断裂概率竞争的观点，提出了SCC的一种概率竞争机制，以解释这种类型的SCC现象，得出了该SCC机制不仅可以解释阳极溶解型SCC裂纹的扩展，也可以解释SCC裂纹的萌生的结论。 |
| 关键词: 不锈钢 应力腐蚀开裂 氯离子 机理 |
| DOI： |
| 分类号: |
| 基金项目:中国科学院院长基金资助项目，1997号 |
|
| A FRACTURE PROBABILITY COMPETITION MECHANISM OF STRESS CORROSION CRACKING |
|
HUANG Yan-liang,HOU Bao-rong
|
|
Institute of Oceanology,The Chinese Academy of Sciences,Qingdao,266071
|
| Abstract: |
| The stress corrosion cracking of Austenitic stainless steel was studied using the polarization technique, slow strain rate and Scanning Electoral Microscopy (SEM) techniques. A number of SCC mechanisms have been proposed, in which the hydrogen embrittlement theory and passive film rupture-repassivation theory are generally accepted. However, they cannot sufficiently explain the SCC mechanism of Austenitic stainless steel in acidic chloride solution, because the steel is in an active dissolution state in the solution, and cathodic polarization can prevent the SCC from occurring. It was found that the SCC of Austenitic Stainless Steel occurred, although the steel was in the anodic dissolution state and the morphology of the fractured surface was characterized by brittle cleavage. This kind of SCC cannot be reasonably explained by the passive film rupture-repassivation theory and by the hydrogen embrittlement theory. In this paper, a fracture probability competition mechanism of SCC was presented, on the basis of: the experimental results of the relationships between anodic dissolution and deformation; strain distribution measurement by Speckle Interferometry; and fractured surface observation combined with the viewpoint of ductile-brittle fracture competition. This kind of SCC mechanisms not only explain the propagation of SCC cracks, but also the crack initiation. |
| Key words: Stainless steel, Stress corrosion cracking, Chloride ion, Mechanism |
