Stainless steel is a popular alloy used in making various industrial products. It’s a versatile material known for its high resistance to corrosion, strength, and durability. Many types of stainless steel are available in the market, but two commonly used are 321 and 304 plates. In this blog post, we will compare these two types of plates to help you better understand the difference between them.
Difference Between Stainless Steel 321 Plates vs 304 Plates
Stainless Steel 321 and 304 are common types of austenitic stainless steel used in industrial applications. Both grades 321 and 304 contain similar proportions of chromium, Nickel, and other metals; however, 304 is slightly higher in chromium, while 321 is higher in Nickel. Regarding corrosion resistance, Grade 304 offers better resistance to general corrosion than Grade 321 due to its lower Chromium-Nickel content. However, when exposed to elevated temperatures up to 900°C (1652°F), Type 321 provides superior performance compared to Grade 304 due to the addition of Titanium that stabilizes the material against sensitization.
Composition
One significant difference between Stainless Steel 321 and 304 plates is their composition. Stainless Steel 321 plates contain less Nickel than 304 plates, but they have Titanium. Titanium enhances its resistance to carbide precipitation during welding and lowers the risk of cracking. On the other hand, 304 plates have a higher amount of Nickel, making them more expensive and resistant to high temperatures. Ultimately, the choice between the two plates depends on the purpose.
The two most commonly used grades of stainless steel are 304 and 321. Both grades are austenitic, meaning they possess a high percentage of Nickel and chromium to provide chemical resistance and durability. The major difference between Stainless Steel 304 Plates and 321 Plates lies in their composition – 304 plates contain 18% Chromium 8-10% Nickel while 321 Plates contain 17-19% Chromium 9-13% Nickel, with higher amounts of Titanium added. This enables SS321 to be better suited for heat applications than SS304, as it can withstand temperatures up to 900°C vs SS304’s maximum temperature of 870 °C.
Corrosion Resistance
Both 321 and 304 plates have excellent corrosion resistance. However, 321 plates are limited to lower temperatures of up to 800⁰F, while 304 plates are ideal for higher temperatures of up to 1500⁰F. 321 plates are well-suited to use in environments with organic chemicals like acetic and citric acids. In comparison, 304 plates have more excellent resistance to most acids, making them ideal for food processing and chemical industries.
Stainless Steel 304 plates and Stainless Steel 321 plates are made of austenitic stainless steel. However, the key difference between them is that Stainless Steel 304 contains mainly chromium and Nickel, while Stainless Steel 321 has more Titanium. This makes Stainless Steel 321 much more intergranular corrosion-resistant than Stainless Steel 304. In addition, when exposed to temperatures between 800°F–1500°F (427°C–816°C), its resistance to oxidation increases compared with other stainless steels like 304. Therefore, for environments with higher corrosion resistance, such as marine or chemical processing applications, SS321 is better suited for these types of environments due to its superior properties.
Strength and Durability
Stainless Steel 321 plates have higher strength and durability than 304 plates. It’s resistant to ageing at a temperature range between 800 ⁰F to 1500 ⁰F and maintains its strength without brittleness. 321 plates also have better creep resistance than 304, making them suitable for use in environments where creep is a significant concern. 304 plates are softer and easier to weld, making them popular in construction and domestic applications.
Stainless steel 321 plates offer superior durability compared to 304 plates – the main difference is that they’re much stronger and more corrosion-resistant. In particular, when exposed to temperatures as high as 900°C, stainless steel 321 resists scaling far beyond what 304 does while at the same time maintaining excellent stability in both low and high temperatures. Furthermore, it has higher resistance than other types of stainless steel against chloride-induced stress corrosion cracking and is often used for parts exposed to marine environments.
Cost and Availability
Stainless Steel 304 plates are costlier than 321 plates due to their high nickel content. 304 plates are readily available in many sizes and thicknesses compared to 321. However, this doesn’t mean you should overlook 321 plates. The lower price of 321 plates makes it a great option for those seeking a cheaper alternative to 304 plates without compromising quality.
Stainless Steel 321 plates are generally more expensive than 304 plates due to their higher Nickel and chromium content. However, 321 plates offer superior corrosion resistance, making them cheaper in certain applications. Additionally, 321 is widely available from various manufacturers and suppliers, making it easier to find what you need for your project than 304.
Conclusion:
In conclusion, the difference between Stainless Steel 321 and 304 plates comes down to the materials’ composition, corrosion resistance, strength, durability, cost and availability. Both plates have unique benefits, and your option depends on your intended use. If you need plates that stand up to high temperatures and most chemicals, go for 304 plates. However, if you’re after a cheaper option for low-temperature welding, Stainless Steel 321 plates are the way to go.
