Neglected Inside Story: Stainless Steel Material
Judging from the name, you might think that stainless steel will never stain-but you are wrong.
Corrosion resistance of stainless steel varies by grade
Stainless steel is less prone to stains than other iron-based metals, but it is not literally "stainless steel". Just like standard steel, stainless steel will leave fingerprints and grease, discolor, and eventually rust. The difference is toughness. Stainless steel can withstand more time and abuse before showing signs of wear.
What is stainless steel?
All steels have the same basic iron and carbon composition, but stainless steel also contains a healthy dose of chromium-this alloy gives stainless steel significant corrosion resistance.
Stainless steel gets its name because of its physical properties and different alloy compositions. Stainless steel contains at least 10.5% chromium. Different grades, it may contain higher chromium content, as well as additional alloy components such as molybdenum, nickel, titanium, aluminum, copper, nitrogen, phosphorus or selenium.
Common stainless steel
The two most common stainless steel grades are 304 and 316. The main difference is the addition of molybdenum, this alloy can significantly enhance corrosion resistance, especially for environments with more salt or chloride exposure. 316 stainless steel contains molybdenum. 304 stainless steel does not.
For outdoor furniture such as railings and bollards, stainless steel is an ideal corrosion-resistant material, but it can withstand long-term exposure only if the grade is suitable for its environment. For most environments, 304 is an economical and practical choice, but it does not have the chloride resistance of 316. The slightly higher price point of 316 is very worthwhile in areas with high chloride exposure, especially near the ocean or heavily salted roads. Each application of stainless steel has unique requirements and requires stainless steel that can perform the task.
304 Stainless Steel
304 stainless steel is the most common form of stainless steel used around the world, due to its excellent corrosion resistance and value. It contains between 16 and 24 percent chromium and up to 35 percent nickel, as well as small amounts of carbon and manganese.
The most common form of 304 stainless steel is 18-8 (18/8) stainless steel, which contains 18 percent chromium and 8 percent nickel. Therefore, it is also called 18/8 kitchen-grade stainless steel or 18/8 pro-grade stainless steel.
Due to its excellent corrosion resistance and value, 304 stainless steel is the most common form of stainless steel in the world.
304 can withstand the corrosion of most oxidizing acids. This durability makes 304 easy to sterilize, so it is ideal for kitchen and food applications. It is also common in buildings, decorations, and venue furnishings.
304 stainless steel does have a weakness: it is susceptible to corrosion by chloride solutions or salt-alkali environments such as the coast. Chloride ions will produce local corrosion areas, called "pitting corrosion", which can diffuse under the chromium protective layer, thereby destroying the internal structure. A solution with a sodium chloride content as low as 25 ppm will begin to cause corrosion.
304 stainless steel is widely used in life. We are familiar with showers, water valves, sinks and water bottles that we often use. All TiwlifeCup products are made of 304 stainless steel. Its quality has passed the FDA inspection.
Common uses of 304 stainless steel:
- Oil storage tank
- Fasteners and finishing hardware (screws, nuts, bolts, plates, handles)
- Pots and pans
- Residential sinks and sink parts
- Interior architecture/decorative hardware (panels, sculptures, wall lamps)
- Equipment tubing
- Household appliances