介绍
Stainless steel is an important material that has been used by construction, engineering and industrial engineers for many years. It is renowned for its strength and the ability to withstand corrosion in many conditions. The ability to select the right type of stainless steel for use in nitric acid is critical for environmental, economical and performance reasons.
Stainless steel is composed of different elements and can exist in various shapes and sizes. Ferritic and austenitic stainless steel are both used for nitric acid applications due to their corrosion resistance. Ferritic stainless steel is magnetic and is composed primarily of chromium and carbon; while austenitic stainless steel is not magnetic and consists mainly of nickel, chromium and nitrogen. Generally, austenitic stainless steel has better corrosion resistance than ferritic stainless steel and tends to more expensive.
Nitric acid is an extremely corrosive acid that is used mainly in industrial processes. It is capable of attacking stainless steel and can cause it to corrode quickly if the wrong grade of stainless steel is not chosen. It is important to note that while there are many austenitic grades of stainless steel, not all are suitable for use in nitric acid. For example, some low nickel alloy grades may be prone to pitting corrosion and reduced pitting resistance in nitric acid, while other high nickel alloy grades may be more resistant.
To ensure optimal performance of stainless steel in nitric acid, it is important to select the most suitable stainless steel grade for the application. The most common grades of stainless steel used in nitric acid are 304, 316 and 317L, which are all austenitic stainless steels. These grades provide excellent corrosion resistance to nitric acid, with 316 and 317L exhibiting additional pitting resistant properties. The grade chosen will depend on the concentration of acid used as well as how frequently the material is exposed to the acid.
When ordering stainless steel for a nitric acid application, it is also important to consider other factors such as the thickness of the material. The thicker the material, the more corrosion resistant it will be. Additionally, some steel may be treated with a sealant or even a special material to increase the corrosion resistance. It is recommended to test the material prior to use, to ensure that the chosen grade is suitable.
In conclusion, stainless steel is an excellent choice for use in nitric acid due to its increased corrosion resistance compared to other materials. Selection of the most suitable grade, taking into account the concentration of the nitric acid and the frequency of exposure is of the utmost importance. When deciding on the grade of stainless steel to use, other factors such as thickness of the material and specialist treatments may also be taken into account to further increase its performance.
