Blog Post Is Stainless Steel Chemical Resistant?

Stainless steel is a material often used in various industries because of its resistance to corrosion and staining. It is essential to be aware of the chemical compatibility of stainless steel with different substances, as some chemicals can cause damage to the metal.

In this guide, we will discuss the chemical resistance of various grades of stainless steel.

Stainless Steel and Chemical Compounds

Most stainless steels contain a chromium-nickel alloy, which provides high levels of resistance to many chemicals. However, some stainless steels are more resistant than others. For example, stainless steel type 304 is considered an excellent chemical resistant stainless steel and the most common grade due to its high corrosion resistance and good strength. On the other hand, stainless steel type 316 is often used in more corrosive environments because of its greater resistance to chemical compounds.

It is important to understand that stainless steels are not impervious to all chemicals; certain compounds can cause damage or cause stainless steel corrosion if it comes into contact with them. Therefore, special care should be taken when selecting stainless steel for chemical processing.

Stainless Steel Chemical Reaction

The stainless steel chemical reaction depends on the type of stainless steel and the chemical compound. Generally, stainless steel reacts with acids by forming hydrogen gas, while alkalis have no effect. However, it is important to note that stainless steel will corrode when exposed to chloride ions, such as those found in salt water or sea air. Stainless steel can also react with other metals, such as copper or iron, forming a galvanic reaction.

When choosing stainless steel for chemical processing, it is crucial to understand the stainless steel grades and their resistance to various chemicals.

Let's discuss a couple of stainless steel grades and their resistance to various common chemicals:

Grade 304

Good resistance to most organic acids (with the exception of acetic acid and salt solutions) and many neutral gases. Poor resistance to halogenated compounds such as chlorine, bromine, and fluorine

Grade 316

Excellent resistance to most acids (including acetic acid), alkalis, salt solutions, and halogenated compounds. Not suitable for use with highly brominated compounds

Grade 321

Excellent resistance to most acids (including acetic acid), alkalis, salt solutions, and halogenated compounds. Not suitable for use with highly chlorinated or brominated compounds

Stainless Steel Chemical Compatibility

The stainless steel chemical compatibility depends on the metal's composition and hardness. While stainless steel is considered a strong metal, it can still be susceptible to corrosion if not properly cared for. Therefore, it is important to understand the stainless steel's chemical compatibility with various substances to prevent any damage or deterioration of the material.

Conclusion

Some grades/types of stainless steel best suited to chemical environments include stainless steel type 304 and stainless steel type 316. It is essential to understand stainless steel's chemical compatibility with various substances to prevent any damage or deterioration of the material. Furthermore, it is necessary to consult a stainless steel chemical resistance guide to determine the stainless steel grade that best suits specific industrial applications. Following these guidelines will ensure optimal performance and longevity from stainless steel products. As a simplified rule of thumb, 316 is best suited to external applications, especially in coastal or marine environments. 304 is best used for indoor applications except in highly corrosive environments, like swimming pools.

If you are looking for stainless steel with superior chemical resistance, contact Leengate Metals today! With over 60 years of experience in supplying stainless steel products, our experts will be able to help you find the perfect stainless steel solution for your needs.