The term stainless steel refers to a family of corrosion-resistant alloys, also known as stainless acid-resistant steels. These steels can be divided into two categories:
- Stainless steels – resistant to weakly corrosive media such as air, steam, and water.
- Acid-resistant steels – resistant to stronger chemical media such as acids, alkalis, and salts.
The difference lies in the chemical composition. Stainless steel with basic chromium content (17–22%) can resist atmospheric and mild corrosion, while the addition of nickel and molybdenum further improves resistance to chloride and harsh environments. Not every stainless steel grade is resistant to chemical corrosion, but acid-resistant steels generally provide stronger protection against rust.
Rather than one single material, stainless steel includes more than one hundred industrial grades, each optimized for specific applications. The key is to select the right composition according to the intended use—whether for decorative, structural, or highly corrosive conditions.