Yes. Stainless means stain-resistant, not stain-proof. Chromium forms a passive oxide layer that protects the steel, but that layer can be broken by salt, acid, prolonged moisture or physical damage, and high-carbon stainless steels lock much of their chromium into carbides where it cannot protect anything.
Chromium in solution reacts with oxygen to form a thin, self-repairing oxide film. Break that film faster than it can re-form and the steel underneath corrodes normally. Chloride ions from salt are particularly good at breaking it, which is why saltwater is the classic enemy.
The other failure is chemical rather than physical: carbon and chromium combine into carbides, and chromium bound into a carbide is not available to form the passive layer. That is why a high-carbon stainless like D2 is called semi-stainless.
Low-carbon, high-chromium steels lead: 420HC, 440A and 7Cr17MoV. Nitrogen-alloyed steels like Nitro-V and MagnaCut get excellent resistance by design rather than by raw chromium content.
High-carbide steels like D2 and S30V are more vulnerable than their chromium figures suggest.
Wipe the blade dry after use. Rinse fresh water over anything that met salt. Do not store a wet knife in a leather sheath, which holds moisture against the steel and is the single most common way good knives get pitted.
A film of light oil on the blade costs nothing and prevents almost everything.
Every steel we stock, with its published composition, hardness range and the trade it makes, is documented in the Steel Lab.