Noun and する verb
ふしょく
ステンレスは腐食作用への耐久性があるんじゃなかったっけ？
Stainless steel is supposed to withstand the corrosion, isn’t it?
When something rots and eats away at something, that is corrosion. Not a good thing.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.