Methodological development of multi-scale characterization toward clarifying hydrogen embrittlement mechanism of multi-phase steels

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K18235
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Structural/Functional materials
• Research Institution: Kyushu University
• Principal Investigator: Koyama Motomichi 九州大学, 工学研究院, 助教 (20722705)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 水素脆化 / 複相鋼 / 損傷成長 / 水素可視化 / 電子チャネリング / ケルビンプローブ / 銀デコレーション

Outline of Final Research Achievements

Here, we focused on developments of characterization techniques for damage evolution and hydrogen visualization in multi-phase steels. Specifically, we obtained following achievements. 1) stable austenite strongly arrest damage growth. Namely, even when damage forms in hydrogen susceptible phase such as BCC martensite, the damage growth stops at austenite region, preventing failure. 2) Electron channeling contrast imaging that visualized twin and dislocations could demonstrate damage formation mechanisms in plate-like martensite. In addition, as the third achievement, we successfully established multi-scale spatially and kinetically resolved hydrogen mapping techniques by using Kelvin probe and silver decoration methods.

Free Research Field

鉄鋼材料強度学