uneven corrosion

...When the average erosion rate in the environment is 0.1 mm/year or less, it is usually called "corrosion resistant." Even if the form is general corrosion, if the corroded surface is rough and uneven, it is called uneven corrosion, and is sometimes included in the localized corrosion below. Localized corrosion is corrosion that occurs in corrosion-resistant materials, and is a form of corrosion that occurs in which the progress of corrosion is concentrated in certain specific locations, even though most of the surface actually shows corrosion resistance in the combination of a material and environment that is originally expected to be corrosion-resistant. ...

*Some of the terminology that refers to "uneven corrosion" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…使用環境での平均侵食率が0.1mm/年以下の場合を通常〈耐食性あり〉と呼んでいる。形態としては全面腐食でも腐食面の凹凸が激しい荒れた状態をとる場合には不均一腐食uneven corrosionと呼び，次の局部腐食のなかに加える場合もある。局部腐食localized corrosionは耐食材料に生ずる腐食で，本来，耐食性が期待される材料と環境の組合せのなかで，実際にも表面の大部分は耐食性を示しているのにもかかわらず，ある特定の場所に腐食の進行が集中する形で起こる腐食の形態をいう。…

※「uneven corrosion」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報