Proposal of galvanic corrosion prevention method for the high-durability bridge by applying stainless steel into the end of the bridge girder

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K22434
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0303:Civil engineering, social systems engineering, safety engineering, disaster prevention engineering, and related fields
• Research Institution: Yamaguchi University (2021); University of the Ryukyus (2020)
• Principal Investigator: Hasuike Rina 山口大学, 大学院創成科学研究科, 助教(テニュアトラック) (80886218)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: 異種金属接触腐食 / ステンレス鋼材 / さび厚

Outline of Final Research Achievements

In order to prevent corrosion of steel bridges, this research aims to realize a highly corrosion-resistance bridge by using stainless steel (SUS) in combination with ordinary steel (SM). To achieve this goal, the level of corrosion in the atmospheric environment of galvanic corrosion, which is a concern at the joint between SUS and SM, attempted to propose a suppression method.
The average rust thickness of SM near the welding after 144 cycles of the corrosion acceleration test by supplying 0.1% NaCl solution was about 4.7 to 4.9 times larger in the SUS-SM test piece than in the SM-SM test piece. In the vicinity of the welding of the SUS-SM test piece, the average rust thickness was about 1.6 times that of the end part of the test piece. From the above, it was suggested that galvanic corrosion between SUS and SM could be suppressed by painting near the welded part (range 0-1 cm).

Free Research Field

鋼構造

Academic Significance and Societal Importance of the Research Achievements

既設橋梁に一般的に用いられている普通鋼材（SM）を対象に材料を選定しており，本成果からステンレス鋼材（SUS）と組み合わせた場合の耐食性が確保できれば，新設，補修問わず高腐食耐久性橋梁の実現に繋がる．これは老齢化が進む我が国の橋梁の維持管理において社会的意義のある成果と考える．また，鋼種および供給溶液塩分量にパラメータを設け，かつさび厚と自然電位双方の計測を試みており，大気環境下における異種金属接触腐食発生要因，発生条件の明確化，適用環境ならびに劣化評価手法の提案に繋がる学術的意義のある成果と考える．