号数	ばね論文集 62 号（ 2017 年）
ページ数	pp.9-14
種類	論文
論文名	酸性溶液中での腐食摩耗による高強度鋼への水素侵入
Title	Hydrogen Entry into a High Strength Steel with Tribocorrosion in Acidic Solution
著者	土井康太郎1)，秋山英二2)
Author	Kotaro DOI1), Eiji AKIYAMA2)
抄録	本研究では，酸性溶液中での腐食摩耗試験による強高度鋼への水素侵入挙動を検討し，中性溶液中での試験結果と比較した。供試体はSCM435鋼とし，腐食摩耗試験では試料を試験溶液に浸漬させながらピン・オン・ディスク型摩耗試験機を用いて試料表面を腐食摩耗させ，浸漬試験では試料を試験溶液に浸漬し腐食させた。試験溶液は酸性〜中性に調整した塩化物イオンを含む溶液とした。鋼材中に侵入した水素量を昇温脱離分析により測定した。中性溶液中では，磨耗腐食により鋼材中に侵入した水素量の方が浸漬試験により侵入した水素量よりも多かった。一方で，pH2.7の酸性溶液中では，試験時間6および12 hでは磨耗腐食による水素量の方が多かったものの，試験時間18時間以降では浸漬試験による侵入量の方が多かった。試験時間48 hの腐食摩耗試験および浸漬試験中の溶液のpH変化に着目すると， pH2.7の溶液では浸漬試験では溶液のpHに変化がほぼなかったにも関わらず，腐食摩耗試験では約6.0まで上昇した。これは，酸性溶液において腐食摩耗試験時にカソード反応によるH+の消費が生じたためであり，その結果，pHが上昇し鋼材の腐食およびカソード反応による水素の発生が抑制されたため，鋼材への水素侵入が軽減されたものと考えられる。
Abstract	Hydrogen entry into a high strength steel with tribocorrosion in acidic solutions was studied in the present study and it was compared with that in a neutral solution. The samples of SCM 435 high strength steel were subjected to tribocorrosion using a pin-on-disk type wear equipment and to static corrosion in neutral and acidic solutions containing Cl-. The hydrogen content entered into the steel was measured using hydrogen thermal desorption analysis. In a neutral solution, the hydrogen content in the tribocorroded sample was larger than that in the corroded sample without wear. In the acidic solution of pH 2.7, the hydrogen content in the tribocorroded sample was also larger than that in the corroded sample without wear in the case of 6 and 12 h duration time. On the other hand, the hydrogen content in the corroded sample without wear became larger than that in the tribocorroded sample after 18 h duration time. In the measurement of pH changes of the solution for the duration of 48 h tribocorrosion test and static corrosion test, it is revealed that the pH of acidic solution during tribocorrosion increased from about 2.7 to 6.0, though the pH of the acidic solution during static corrosion test revealed little variation. Because H+ consumption by hydrogen generation in cathodic reaction was enhanced with tribocorrosion in acidic solution. The concentration of H+ decreased gradually and pH became higher. As a result, corrosion of the steel and hydrogen generation were suppressed and hydrogen entry into the sample was diminished.
著者の所属	1)国立研究開発法人物質・材料研究機構 2)東北大学
Belonging	1)National Institute for Materials Science 2)Tohoku University
Key Words	Hydrogen entry, Hydrogen embrittlement, Corrosion, Wear, Acidic solution, High strength