DO YOU KNOW YOUR STAINLESS STEEL?

DO YOU KNOW YOUR 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 localized corrosion resistance against pitting. Other alloy metals such as copper, titanium, and vanadium are also added to enhance the properties and structure of stainless steel. There are more than 150 grades of stainless steel available.

Stainless steel is usually divided into five types:

1. Ferritic – This type of stainless steel is in the 400 grade and contains 10.5% - 20% chromium, making it highly resistant to scaling and cracking at elevated temperatures. It cannot be heat treated but can be cold worked and softened by annealing. It is magnetic and typically found in applications where corrosion resistance is important, such as kitchens and automotive fields.
2. Austenitic – This type is the most commonly used, including all 200 and 300 grades, which contain 15% – 30% chromium and 2% – 20% nickel for enhanced surface quality, formability, corrosion, and wear resistance. Generally non-magnetic, austenitic stainless steel is widely utilized in automotive trim, cookware, processing equipment, and various industrial applications.
3. Martensitic – This type falls into the 400 grades comprising straight chromium steel with 11.5% – 18% chromium. Developed for corrosion resistance, martensitic stainless steel can be hardened through heat treatment. Typically magnetic, it's often used in products where hardness, strength, and wear resistance are necessary, like food ware and multipurpose tools.
4. Duplex - A more recent variety, duplex stainless steel combines austenitic and ferritic types, resulting in higher strength and enhanced resistance to stress corrosion cracking, often a result of nitrogen addition to the alloys, improving strength and weldability.
5. Precipitation hardening (PH) – This type provides a unique combination of fabricability, strength, ease of heat treatment, and corrosion resistance found in no other class of material. Precipitation hardening grades are primarily used for bars, rods, wires, and forgings but are increasingly available in flat-rolled forms.

The most common types of stainless steel we sell are grades 304 and 316, which fall under the austenitic family.

Grade 304: This grade offers 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: Known for its higher level of corrosion resistance compared to grade 304, grade 316 is often referred to as marine grade stainless steel. It is typically used in marine applications and architectural components exposed to coastal environments.

Before choosing a stainless steel type, always check whether it meets the specific requirements for your application, as not all types are suitable for every use, including compliance with any relevant building codes or standards.

For more information, make sure you check out our range of stainless steel products today. If you can’t find what you’re looking for, contact an All Lifting specialist at 1300 666 733!