A stainless steel can have good corrosion resistance in many media, but in another medium, it may corrode due to low chemical stability. Therefore, a stainless steel cannot be resistant to all media. In many industrial applications, stainless steel can provide satisfactory corrosion resistance. According to the experience of use, in addition to mechanical failure, the corrosion of stainless steel is mainly manifested in: a serious form of corrosion of stainless steel is localized corrosion (ie stress corrosion cracking, pitting corrosion, intergranular corrosion, corrosion fatigue and crevice corrosion) .
The failure cases caused by these localized corrosion accounted for almost more than half of the failure cases. In fact, many failure accidents can be avoided through reasonable selection of materials. The corrosion of metals can be divided into three types according to the mechanism: special corrosion, chemical corrosion and electrochemical corrosion. The vast majority of metal corrosion in practical life and engineering is electrochemical corrosion.
