Clarification of crack initiation mechanism under irradiation and fatigue and development of method for detecting and lengthening initiation life by nano-level analysis of surface morphology

阐明辐照和疲劳下裂纹萌生机制，开发通过表面形貌纳米级分析检测和延长裂纹萌生寿命的方法

• 批准号: 23760803
• 负责人: NOGAMI Shuhei
• 金额: $ 2.83万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2011
• 资助国家: 日本
• 起止时间: 2011 至 2013
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-23760803/
• 关键词: 低放射化フェライト鋼; 溶接部; 疲労; 照射損傷; 微小き裂発生; 表面構造

The objective of this study is to clarify the crack initiation mechanism under irradiation and fatigue damages in the reduced activation ferritic steel and its weld, and to develop the index for detecting the crack initiation and the method for lengthening the initiation life.It was clarified that the crack initiation occurred at the prior austenitic grain boundary, the packet boundary, the block boundary, and the inside of the block structure. Most of the crack initiation was observed in the matrix. The irradiation damage induced the shortening of the initiation life. No change of the initiation sites and their ratio occurred due to the irradiation damage.The suppression of the crack growth by the prior austenitic grain boundary was clarified regardless of the irradiation damage. Based on this result, the fatigue crack initiation under the irradiation damage would be suppressed by the optimization of the grain size and the probability of the existence of the grain boundary.

本研究的目的是阐明低活化铁素体钢及其焊缝在辐照和疲劳损伤下的裂纹萌生机理，开发检测裂纹萌生的指标和延长裂纹萌生寿命的方法。裂纹萌生发生在原奥氏体晶界、包边界、块边界和块结构内部。大部分裂纹萌生是在基体中观察到的。辐照损伤导致引发寿命缩短。由于辐照损伤，引发位点及其比例没有发生变化。无论辐照损伤如何，原奥氏体晶界对裂纹扩展的抑制作用都得到了阐明。基于这一结果，可以通过优化晶粒尺寸和晶界存在的概率来抑制辐照损伤下疲劳裂纹的萌生。

项目成果

低放射化フェライト鋼の疲労特性に及ぼすヘリウムの影響

氦气对低活化铁素体钢疲劳性能的影响

• 发表时间: 2012
• 作者: 中井亮介;野上修平;長谷川晃;谷川博康;濱口大
• 通讯作者: 濱口大

Effect of Irradiation on Micro-Crack Initiation in Fatigued Austenitic Stainless Steel

辐照对疲劳奥氏体不锈钢微裂纹萌生的影响

• 发表时间: 2011
• 作者: S. Nogami; Y. Sato; A. Hasegawa
• 通讯作者: A. Hasegawa

低放射化フェライト鋼溶接継手における疲労破損挙動の解析

低活化铁素体钢焊接接头疲劳失效行为分析

• 发表时间: 2013
• 作者: 野上修平;宇佐美博士;福田誠;藪内聖皓;長谷川晃;谷川博康
• 通讯作者: 谷川博康

低放射化フェライト鋼の疲労き裂発生挙動に及ぼす照射損傷の影響

辐照损伤对低活化铁素体钢疲劳裂纹萌生行为的影响

• 发表时间: 2012
• 作者: 山本雄也;中井亮介;野上修平;藪内聖皓;長谷川晃
• 通讯作者: 長谷川晃

Effect of Irradiation on Micro-Crack Initiation in Fatigued Austenitic Stainless Steel

辐照对疲劳奥氏体不锈钢微裂纹萌生的影响

• 作者: Shuhei Nogami; Yuki Sato; Akira Hasegawa
• 通讯作者: Akira Hasegawa