Black spotting/dust in stainless steel utensils.Is this mildew

cleaningcookwaremoldpanstainless-steel

I moved into this house a couple of months ago and bought some high quality stainless steel utensils with me from my house. I am noticing some black spots that don't go away with scratching or washing or baking soda. All my stainless steel kitchen utensils have this and some plastic containers have black dust which could be wiped with a dry paper towel.

My mum has been using the same set of utensils for years and has never observed anything like this. The only difference is that I wash my utensils with warm to hot water(and fairy dish soap).These spots also seem to increase in number(not in thickness) day by day. Have any of you heard or seen anything like this in stainless steel utensils ? What could this possibly be?

(There is a lining of black mold in the sealant lining the wall near the sink and also some in the shower which was scraped away when I moved in)

enter image description here

enter image description here

Best Answer

The specks are corrosion pits. Austenitic stainless (aka- 18-8 , 304 , and several other numbers) are notorious for pitting in salt (halides). The 316 and 317 with molybdenum are more resistant but I doubt any cookware producer would go to the extra expense to use these alloys. However, I expect sitting for a couple days with salted water would be needed for pitting to develop. Out of curiosity, check it with a magnet; If strongly magnetic it is likely 13 Cr (410 SS) which would be likely to pit.