UNS S31803 and SS317L are two different grades of stainless steel, each with its own composition and characteristics. Here are the main differences between them:

Composition: UNS S31803 Sheet is duplex stainless steel, which means it is a combination of austenitic and ferritic stainless steel. It typically contains about 22% chromium, 5-6% nickel, 3% molybdenum, and smaller amounts of other elements such as nitrogen and manganese. On the other hand, SS317L is an austenitic stainless steel, which contains about 16-18% chromium, 10-14% nickel, 2-3% molybdenum, and smaller amounts of other elements.

Corrosion resistance: Both UNS S31803 and SS317L are known for their good corrosion resistance. However, UNS S31803, being duplex stainless steel, has better resistance to chloride-induced stress corrosion cracking (SCC) and pitting corrosion compared to SS317L, especially in environments with high chloride content, such as marine environments or those containing brines and chlorides.

Strength and toughness: UNS S31803 is generally known for its higher strength compared to SS317L, which makes it suitable for applications where higher mechanical strength is required. It also has good toughness and ductility.

SS 317L Sheet, on the other hand, has lower strength compared to UNS S31803 but exhibits higher elongation and better impact resistance.

Heat resistance: SS317L has better heat resistance compared to UNS S31803. SS317L can withstand higher temperatures without losing its mechanical properties, making it suitable for high-temperature applications, whereas UNS S31803 may experience reduced toughness and corrosion resistance at elevated temperatures.

Cost: Generally, duplex stainless steels such as UNS S31803 tend to be more expensive compared to austenitic stainless steels like SS317L due to their higher alloying content and unique properties.

In summary, while both UNS S31803 and SS317L are stainless steels, they have different compositions, properties, and applications. UNS S31803 is duplex stainless steel with better resistance to chloride-induced stress corrosion cracking and higher strength, while SS317L is an austenitic stainless steel with better heat resistance. The choice between the two would depend on the specific requirements of the application, such as the environment, temperature, and mechanical properties needed. It is important to consult with a materials engineer or metallurgist to determine the most suitable stainless steel grade for a particular application.

Calico Metal Alloys LLP is one of the main Manufacturers, Suppliers and Exporters of UNS S31803 Sheet, SS 317L Sheet, Duplex S31803 Pipe, UNS S31803 Plate