Several stainless steel grades, the most popular and common of which are type 304 and type 316. Both are fantastic for lots of uses. Selections will vary depending on how much corrosion resistance and cost are needed for the application. 316 stainless steel has better corrosion resistance than 304 stainless steel and has good resistance to corrosion in the production of pulp and paper. 304 Stainless steel is less expensive and more flexible than some other protective covers for indoor applications, such as outdoor kitchen hardware and water pipes. 304 stainless steel is non-magnetic and has excellent corrosion resistance. 304 SS is cheaper and more cost-efficient in most normal applications. 316 stainless steel contains 2-3% molybdenum, 16% chromium, and 10 % nickel. Much improved corrosion resistance with the addition of molybdenum. The alloy characteristics of 316 SS make it more costly.
Key Differences between 304 and 316
There are two types of steel, which are 304 and 316 stainless steel. What’s the difference between 304 and 316 stainless steel?
304 stainless steel: the most common grade; the classic 18/8 stainless steel, which has better resistance to pitting and crevice corrosion than alloy 400.
316 stainless steel: with the addition of molybdenum. When you add molybdenum, this increases resistance to chlorides and acid even more, and makes 316 even better for use in this harsh material like coastal areas (saltwater is a big one) or places where saltwater meets industrial chemicals. 316 is more corrosion-resistant than 304, but also more expensive, and for most basic use cases, such as the kitchen sink and food handling equipment, 304 is fine. 316 is the preferred choice whenever corrosion resistance and processability improvement are necessary in applications.
Similarities between 304 and 316
Although they belong to two vastly different families, 304 and 316 are very similar. Each of them is a member of the authentic family, and they have good formability and great durability. They are also non-magnetic in the annealed conditions and not hardenable by heat treatment. 2 All grades have a bright, shiny look similar to the electrorefined grade.
Notably, pure versions of the metals are used in specialty applications where high purity is required, involving both the chemical and food industries ( preferring 316 and 304 stainless steel). Corrosion resistance of iron-chromium alloy may have been first recognized in 1821 by Pierre Berthier, who noted their resistance against attack by some acids and suggested their use in cutlery. Both types (301 SS and 304 SS) of stainless steel are part of the austenitic family of stainless steel and are extremely similar, with the exception of this minor difference. This makes them very long-lasting, hygienic, and simple to wash. As a result, the combination of 304 and 316 is known to be widespread in food service, architecture, and chemical industries requiring these common factors. The susceptibility to the latter is due to the lack of resistance by these alloys against chlorine-containing media unsuitable for such cases.
Types of stainless steel
The two most common types of stainless steel are:
- 304 Stainless steel
- 316 Stainless steel
What is 304 stainless steel?
304 stainless steel is the most widely used and versatile of austenitic chromium-nickel stainless steel. It is an industry standard due to its outstanding performance in many applications. The 304 stainless steel round rod has an unpolished (mil) surface, meets the American Society for Testing and Materials international ASTM A276 specification, and has a standard tolerance. Its principal content is about 18% chromium and 8% nickel. The chromium forms a passive state oxidation film, which even loses chromium, and the nickel implements the austenite stable parent phase; the former can make steel have corrosion resistance, and the latter ensures the high ductility of steel formability. It has excellent resistance to a broad range of chemicals, food products, and potable water.
Because of these characteristics its uses are numerous. It is widely utilized in kitchen applications and for commercial use of food equipment, architectural trim, chemical containers, etc. 304 stainless steel is less strong than other types of steel. It is unsuitable for environments with salt or strong chemicals; it may corrode in marine or industrial conditions. Where 316 grade is preferred, because of the presence of molybdenum.
What is 316 stainless steel?
316 stainless steel is a high-performance austenitic part of stainless steel. This makes it a superior choice to the more common 304 stainless steel in many aggressive environments. 316 stainless steel is non-reactive and very safe for use as the contacting material must be of various sensitivities. 316 stainless steel provides strong performance at high and low temperatures, which allows for considerable use. It is more expensive but is durable in corrosive applications, providing it as a cost-effective solution over the lifetime of the fixture or system. Common applications include surgical instruments, pharmaceutical equipment, boat fittings, and industrial tanks that require proven resistance to decay and extreme service conditions.
Conclusion
In conclusion, both 304 and 316 stainless steel offer excellent corrosion resistance and mechanical properties. Type 304 with its chromium-nickel content, is a versatile and cost-effective choice for most general-purpose applications. And type 316 stainless steel is unequivocally superior. The addition of molybdenum provides a significant boost. It’s used in a heat exchanger, chemical processing equipment, and marine parts.