Basic Cognition & Anti-Rust Principle of Stainless Steel

Q1: What is the main composition of stainless steel that ensures its corrosion resistance? A1: The key component is chromium (content ≥10.5%). Chromium reacts with oxygen in the air to form a dense passive oxide film on the surface, which isolates the internal metal from the external environment and achieves anti-corrosion effect. Adding nickel, molybdenum and other elements can further enhance corrosion resistance.

Q2: Is stainless steel completely rust-proof? A2: No, it is not completely rust-proof. The passive film on the surface of stainless steel may be damaged by strong acids, strong alkalis, or mechanical scratches. If not maintained in time, the exposed metal will react with the environment and cause rust. However, its rust resistance is far superior to that of carbon steel.

Q3: What is the difference between stainless steel and carbon steel in terms of performance? A3: Compared with carbon steel, stainless steel has obvious advantages in corrosion resistance and hygiene; in terms of strength, some high-grade stainless steel (such as duplex stainless steel) is higher than carbon steel; in terms of appearance, stainless steel has a smoother and more beautiful surface and is easier to clean. The disadvantage is that the cost is generally higher.

Q4: What are the common units for measuring the thickness of stainless steel products? A4: Common units include millimeters (mm) and gauge (GA). For example, 1mm thickness is approximately equivalent to 18 gauge. It should be noted that the gauge standard varies in different regions and industries. It is recommended to confirm the specific thickness value (mm) when purchasing to avoid misunderstandings.

Q5: What are the main international standards for stainless steel? A5: The common ones include ASTM (American Standard), DIN (German Standard), EN (European Standard) and GB (Chinese Standard). For example, 304 stainless steel corresponds to ASTM A240, DIN 1.4301, etc. Buyers should select the corresponding standard products according to the requirements of the target market.