報告書番号

N08078

タイトル（和文）

渦電流を用いた亜鉛被覆鋼撚り線の腐食劣化診断技術 -３年間の自然暴露における腐食劣化挙動に基づく腐食量の評価方法-

タイトル（英文）

Diagnosis Method of Corroded Messenger Wire of Twisted Zinc-coated Steel by Eddy Current - Evaluation Method of Corrosion based on the Corrosion Behavior of Natural Exposure Tests for Three Years -

概要 （図表や脚注は「報告書全文」に掲載しております）

通信ケーブル用吊線として用いられている亜鉛被覆鋼撚り線を用いて, ３年間におよぶ自然暴露腐食試験を行った. 腐食した試験片と試作した渦電流測定計器を用いて, 非接触で亜鉛の残存平均膜厚と鋼の残存平均断面積を測定し, 架線の腐食劣化を非破壊で調べる方法について検討した．その結果, 実際の腐食挙動が渦電流特性に及ぼす影響を明らかにした．鋼の劣化曲線はマグネタイトの生成により上昇し, 亜鉛の劣化曲線はZn-Fe合金相の影響を受ける. また，渦電流のX信号(V)と位相角（度）を用いて評価することにより, 亜鉛の残存膜厚と鋼の残存断面積を精度良く推定できる．また, 吊線の腐食速度を別途把握することにより, 劣化量の予測が可能となる．

概要 （英文）

The natural exposure tests for three years were conducted for the messenger wire of twisted zinc-coated steel for the communication. In addition, the residual thickness of zinc and section area of steel were measured by using trial manufactured Eddy current testing (ECT) meter and several corroded wire test pieces. Then, the non-destructive measurement method of the corroded wire was developed. As a result, the effect of the corrosion behavior of wire on ECT signal became clear. The degradation curve of steel were increased to the direction of Y-signal(V) by creation of Magnetite. Furthermore, the degradation curve of zinc were influenced by the existence of Zn-Fe alloy phase. Also, both of the residual thickness of zinc and section area of steel can be estimated by using the evaluation of X-signal (V) and phase (degree) with sufficient accuracy. By obtaining the corrosion rate of wire, the estimation of corrosion progress values become to be possible.

報告者

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