Do You Know Your Stainless Steel?
What we’ve learnt about Stainless Steel
Stainless Steel is a metal alloy, made up of steel combined with elements like chromium, nickel, molybdenum, silicon, aluminium and carbon. Iron combined with steel is the main part of what makes stainless steel what it is.
Chromium is what makes stainless steel resistant to rust. Nickel increases corrosion resistance; Molybdenum adds localised corrosion resistance against pitting. Other alloy metals like copper titanium and vanadium are also added in order to increase the properties and structure of stainless steel. There are more than 150 grades.
Stainless steel is usually divided into 5 types
- Ferritic – This type of steel is in the 400 grade and contains 10.5% - 20% chromium and is highly resistant to scaling and cracking at elevated temperatures. It cannot be heat treated, however can be cold worked and softened by annealing. It is magnetic and typically used in applications where corrosion resistance is important, such as kitchens and automotive applications.
- Austenitic – This type of stainless steel is the most commonly used. All 200 and 300 grades are austenitic and contain 15% – 30% chromium and 2% – 20% nickel for enhanced surface quality, formability, corrosion and wear resistance. They are generally non-magnetic and are commonly used for automotive trim, cookware, processing equipment and a large range of industrial applications.
- Martensitic – This type of stainless steel which is also in the 400 grades are straight chromium steel with 11.5% – 18% chromium. It was developed to be corrosion resistant and hardenable by heat treating. It is magnetic and usually used where hardness, strength and wear resistance is required, such as food ware and multipurpose tools.
- Duplex - A newer type of stainless steel, it is a combination of austenitic and ferritic types and produces a higher strength and superior resistance to stress corrosion cracking. Nitrogen is added to second generation duplex alloys and provides strength and increased weldability.
- Precipitation hardening (PH) – This type of stainless steel provides a unique combination of fabricability, strength, ease of heat treatment and corrosion resistance not found in any other class of material. Precipitation hardening grades are primarily used for bars, rods, wire and forgings but increasingly in flat-rolled form.
The most common types of stainless steel we sell are grades 304 and 316 which fall under the Austenitic family.
Grade 304: Has good corrosion resistance and is one of the most commonly used grades of stainless steel. It has a slightly higher carbon content than grade 316.
Grade 316: Has a higher level of corrosion resistance than grade 304. This grade is often referred to as marine grade stainless steel. Typical applications are marine and architectural components near exposed coastal locations.
Always check the type of stainless steel required for your application as not all types are suitable for all applications including compliance with any relevant building codes or standards.
Make sure you check out our range of stainless steel products today. Can’t find what you’re looking for? Call an All Lifting specialist today on 1300 666 733!