Study on Behavior of Micro crack and Propagation Characteristic of Mild Steels in Corrosive Environment

腐蚀环境下低碳钢微裂纹行为及扩展特性研究

• 批准号: 06650529
• 负责人: KOTOGUCHI Hisao
• 金额: $ 1.09万
• 依托单位: Daido Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06650529/
• 关键词: Fatigue; Corrosive Fatigue; Microcrack; Occurrence of Crack; Fracture Mechanics; Stress Intensity Factor; Process Zone; Crack Propagation

1. Multiple initial cracks initiate and one of these cracks that has most developed process zone has microcrack. Microcrack propagated along the grain boundary.2. In the behavior of microcrack propagation, there were three steps. In the first step, process zones 1 the crack propagated along the grain boundary in zigzag direction, near the root of two process zones. microcrack stopped propagating until growing of new process zone. Microcrack propagated by the this behavior.It has been able to estimate relationship between microcrack growth rate and stress intensity factor has found to propagate when K is less than its lower limit of long crack that is general consideratic crack growth rate in microcrack decreased in accordance with an increase of stress intensity factor.4. Behavior of crack opening and closure was found to occur even in microcrack.Fractogragrapy of corrosive and atmospheric fatigue crack are permed by scanning electron microsc clear the difference in two types environments.

1.多个初始裂纹萌生，其中一个裂纹最发达的过程区有微裂纹。微裂纹沿着晶界扩展.微裂纹的扩展行为分为三个阶段。在第一步中，加工区1裂纹在两个加工区的根部附近沿晶界以Z字形方向沿着扩展。微裂纹停止扩展直至新的加工区生长。微裂纹的扩展是由这种行为引起的，已经能够估算出微裂纹扩展速率与应力强度因子之间的关系，发现当K小于其下限时，微裂纹扩展，即一般情况下，微裂纹中的裂纹扩展速率随着应力强度因子的增大而减小.用扫描电镜观察了腐蚀和大气疲劳裂纹的断口形貌，发现在两种环境下裂纹的张开和闭合行为有明显的差异。

项目成果

事口 壽男,他: "腐食環境下における微視き裂挙動に関する考察" 土木学会中部支部研究発表会講演概要集. I-11. 21-22 (1996)

Toshio Kotoguchi 等人：“腐蚀环境中微裂纹行为的研究”中部分会研究报告摘要，日本土木工程师学会 I-11 (1996)。

事口 壽男,他: "予き裂形状の差異による鋼の微視き裂進展挙動に関する研究" 土木学会中部支部研究発表会. I-33. 69-70 (1995)

Hisao Kotoguchi 等人：“由于预裂纹形状差异而导致的钢微观裂纹扩展行为的研究”日本土木工程师学会中部分会研究报告 I-33 (1995)。

事口 壽男: "鋼の微視き裂進展挙動の動的観察" 日本鋼構造協会構造年次論文報告集. Vol.2. 495-500 (1994)

Hisao Kotoguchi：“钢中微裂纹扩展行为的动态观察”日本钢结构协会年度结构论文报告第 2 卷 495-500 (1994)。

事口 壽男,他: "微視き裂における表面と内部のき裂進展挙動について" 土木学会中部支部研究発表会. I-32. 67-68 (1995)

Hisao Kotoguchi 等人：“微观裂纹的表面和内部裂纹扩展行为”日本土木工程师学会中部分会研究报告 I-32 (1995)。

H.Kotoguchi, T.Ito and T.Yamamori: "Fundamental Study on Occurrence Organization of Steel Microcrack" Annual Meeting of JSCE. I-293. 584-585 (1994)

H.Kotoguchi、T.Ito 和 T.Yamamori：“钢微裂纹发生组织的基础研究”JSCE 年会。