Understanding initiation processes of stress corrosion cracking by means of real time imaging and development of anti-SCC materials

通过实时成像了解应力腐蚀开裂的引发过程和抗SCC材料的开发

• 批准号: 22246092
• 负责人: WATANABE Yutaka
• 金额: $ 21.8万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2010
• 资助国家: 日本
• 起止时间: 2010 至 2012
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-22246092/
• 关键词: 応力腐食割れ; 発生過程; 視覚化; すべり溶解機構; 発色反応; δフェライト; オーステナイト系ステンレス鋼; き裂停留; δ－フェライト; 電気化学的過渡信号; 介在物; すべり溶解; 低ひずみ速度試験; 応力腐食割れ; 発生過程; 視覚化; すべり溶解機構; 発色反応; δフェライト; オーステナイト系ステンレス鋼; き裂停留; δ－フェライト; 電気化学的過渡信号; 介在物; すべり溶解; 低ひずみ速度試験

A visualization method has been developed, where local and transient anodic events occurring in initiation processes of stress corrosion cracking can be observed in a wide window and in real time. The initiation process was found to be intermittent and very small-scale anodic events and their repassivation. Cracks tend to initiate at the location where a few anodic events occur in proximity to each other. In most cases, oxide inclusions containing Si, Mg, or Al, provided initiation sites. Stress corrosion cracks tend to retard when they reach δ-ferrite located on grain boundaries (especially on triple points). We may be able to effectively improve SCC initiation life of steels by locatingδ-ferrite on grain boundaries as much as up to a few % of volume fraction.

已经开发了一种可视化方法，其中可以在宽阔的窗口和实时观察到应力腐蚀破裂过程中发生的局部和瞬态阳极事件。发现触发过程是间歇性且非常小的阳极事件及其重新启动的。裂缝往往会在彼此接近发生一些阳极事件的位置启动。在大多数情况下，含有Si，Mg或Al的氧化物夹杂物提供了起始位点。当应力腐蚀裂纹达到位于晶界（尤其是在三个点上）的δ-有限时，它们往往会阻碍。我们可能能够通过在晶界上定位δ-有限量来有效地改善钢的SCC倡议寿命，最多只有几％的体积分数。