Stainless steel is an enormously beneficial product, one used for a variety of applications and needs. Known for everything from corrosion resistance to its fantastic aesthetics, stainless steel is one of the most popular metals in the entire world for industrial applications — but it has a number of grades, and knowing which to choose is very important.
At Wasatch Steel, we’re happy to provide clients with a huge range of steel products, from steel sheet to steel pipe, steel bar and more for clients around Utah. What are the different grades of stainless steel out there, and what are the factors you should be considering while choosing the right one for your needs? Here’s a primer.
While this list isn’t exhaustive, here are some of the most common stainless steel alloys and grades that are used in various applications:
Our next several sections will go over the important variables to evaluate as you’re choosing the proper stainless steel type and grade for your next project.
One of the single most important factors you’ll want to consider when choosing a stainless steel alloy is its corrosion resistance. The austenitic grades are the most resistant to corrosion, while the martensitic and ferritic grades are less so. If your application is in a highly corrosive environment, you’ll want to make sure to select an alloy with good corrosion resistance.
Some of the more common corrosive elements are acids, chlorine and certain salts. Acids include hydrochloric, sulfuric, nitric and phosphoric acid. Chlorine is often found in hot water tanks where it causes the release of hydrogen gas. Corrosion resistance can be affected by heat — so if you’re working with a stainless steel alloy that’s known to be resistant in room-temperature environments, it may not hold up so well when exposed to direct heat.
Formability and weldability are two additional important factors for consideration as you choose a stainless steel alloy. The austenitic grades tend to be the easiest and most formable types — but they can also be the most expensive. The martensitic and ferritic grades are less formable, but they’re also less expensive.
Weldability is another important factor to consider, as it’s often necessary to weld stainless steel components together in order to create a finished product. Some of the more difficult-to-weld alloys include the martensitic and ferritic grades.
Environment types may include low pH, stressors, widely changing temperatures, highly corrosive conditions and extremes in pH levels. Grades like 304 and 316 often have some of the best performance when it comes to corrosion and stress.
Two particular alloy types are best-known for strength and ductility within stainless steel: Chromium and nickel. Chromium is known for its strength, with nickel adding to its durability and lowering the alloys’ melting point. When choosing stainless steel grades for their strength, you’ll normally want to stick to one of these two alloy combinations.
To determine your desired weight, it’s helpful to consider what you’re using the finished product for. For instance, if you’re building a material handling product, it will be useful to know how heavy the alloy needs to be in order for it to bear weight without damage.
One of the simplest methods many project managers use to identify the proper stainless steel grade for their needs is looking at maximum use temperature or melting point. In order to determine your maximum operating temperature, make sure you know the highest temperature your application will reach.
If a given stainless steel doesn’t meet the specifications you require, you can quickly strike it off the list and continue on.
There are many different grades, variants or “types” of stainless steel available to choose from for your specific needs. Each one varies in price, ease of fabrication/shaping/machining, corrosion resistance and so forth. For more assistance with choosing the right type and grade of stainless steel, or for any of our other steel products or services in Utah, speak to the staff at Wasatch Steel today.