Investigation of hydrogen assisted crack growth mechanism in very long life regime based on the evaluation of local mechanical properties

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05686
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Aoyama Gakuin University
• Principal Investigator: Ogawa Takeshi 青山学院大学, 理工学部, 教授 (50167318)
• Co-Investigator(Kenkyū-buntansha): 蓮沼 将太 青山学院大学, 理工学部, 助教 (50709764)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 構造・機能材料 / 材料強度 / 局所力学特性 / 水素助長き裂進展機構 / 超長寿命域 / インデンテーション法

Outline of Final Research Achievements

The present study developed an improved method to estimate local mechanical properties by indentation tests and investigated the humid gas stress corrosion cracking (HG-SCC) characteristics of aluminum alloys for hydrogen containers and the effect of hydrogen on the fatigue strength of very high cycle regime. The developed indentation method enabled us to predict local stress-strain response in the plastic region in terms of the observation of dents impressed on the specimen surface. However, it was found that this method had size effect attributed to the geometrically necessary dislocation and that the behavior was essential phenomenon. Therefore, other methods were used to investigate the mechanisms of HG-SCC of aluminum alloys and the very high cycle fatigue of bearing steels.

Free Research Field

材料強度学