Stainless steel is a cost-effective and corrosion-resistant material that is highly durable, with a smooth surface finish and excellent strength. Stainless steel seamless pipes/tubes are commonly used in commercial and industrial applications, particularly for fluid transportation.
Types of Stainless Steel Seamless Pipes
According to metallographic structures of stainless steel, stainless steel seamless pipes can be divided into:
1. Austenitic Stainless Steel Seamless Pipes
Austenitic stainless steel is the most widely used type of stainless steel globally. By increasing the percentage of chromium, molybdenum, and nitrogen in the base alloy, the corrosion resistance of austenitic stainless steel can be further improved. Additionally, the steel becomes non-magnetic and can be easily bent, drawn, or formed. It is important to note that austenitic stainless steel cannot be hardened through heat treatment. Austenitic stainless steel is typically classified into 200 and 300 series. Grade 304/304L is the most commonly used stainless steel in the food industry.
2. Ferritic Stainless Steel Seamless Pipes
Ferritic stainless steel has a high chromium content but low carbon content (usually below 0.1 percent). It is based on the body-centred cubic crystal structure of iron combined with a small percentage of chromium. Although it can be cold worked, it cannot be heat treated. Despite its low welding resistance, ferritic stainless steel has exceptional resistance to stress corrosion cracking. It is similarly magnetic to martensitic steels. The most common ferritic grades are 430 and 409, which are mostly used in the automotive sector.
3. Martensitic Stainless Steel Seamless Pipes
Martensitic stainless steel is a type of stainless steel with a low nickel content and a high carbon content of up to 1 percent. This high carbon content allows it to be hardened and tempered, making it extremely hard and ideal for applications where strength, hardness, and wear resistance are essential. Unlike typical austenitic stainless steel, martensitic stainless steel is magnetic. Common grades of martensitic stainless steel include 410, 420, and 440C.
4. Duplex and Super Duplex Stainless Steel Seamless Pipes
Duplex and super duplex stainless steel are a combination of ferritic and austenitic stainless steels. They can only be hardened through cold working. The most commonly used grades are 904L and 2205, which contain higher levels of chromium, nickel, and other alloying elements such as nitrogen or copper to enhance their structure and performance. Duplex and super duplex stainless steel are commonly used in applications that require high strength due to their excellent mechanical strength, high corrosion resistance, and good weldability. These materials are preferred for their ability to withstand harsh environments and maintain their structural integrity. It is important to note that duplex and super duplex SS should be used in accordance with industry standards and guidelines to ensure optimal performance and longevity.
Depending on the manufacturing method, there are:
- Hot rolled
- Cold worked(cold-rolled and cold-drawn)
Post time: Jan-17-2024