Stainless steel is a popular and great choice for many applications across industries. It is durable, strong, and corrosion-resistant. There are many types of stainless steel tubes available, which differ from each other in several ways. Two of the most popular grades are 904L and 304 stainless steel tubes. Let us take a closer look at the key differences between these two types of stainless steel tubes.
904L Stainless Steel Tube
904L stainless steel has low carbon content and is non-stabilized austenitic steel. The 904L stainless steel tube offers excellent weldability, formability, and toughness compared to other stainless steel tubes in the market. It also has high resistance to stress corrosion cracking and crevice corrosion due to low carbon and nickel content. They also show good corrosion resistance in non-oxidizing acids like acetic acid, sulfuric acid, phosphoric acid, formic acid, etc., as well as in neutral chlorine-containing media.
This grade of stainless steel is very much suitable for sulfuric acid of various concentrations below 70 degrees Celsius. It is designed for use in environments with harsh corrosion conditions. The copper content in 904L stainless steel makes it highly acid-resistant. These tubes are widely used in chemical processing equipment, heat exchangers, medical instruments, food handling equipment, chemical storage tanks, valves, pumps, pressure vessels, nuclear reactors, etc.
304 Stainless Steel
304 stainless steel is austenitic grade with 8-10% nickel and 18-20% chromium. It is alloyed with iron as the primary alloying element and offers excellent formability and weldability. 304 stainless steel tube provides high oxidation resistance, making them ideal for applications where oxidation is an issue.
This includes marine applications and chemical processing areas where chlorine or sulfur compounds may be present. It also has excellent resistance to corrosion from chloride solutions, making it perfect for applications like medical instruments that come into contact with salt water, brine solutions, or food handling equipment.
304 stainless steel is non-magnetic and also shows good mechanical properties. The tube can maintain high strength even at elevated temperatures of up to 870 degrees Celsius. It offers much better creep strength compared to other grades of stainless steel. These qualities make it usable for food processing equipment, water supply lines, medical devices, and architectural trim applications.
Its excellent resistance to corrosion as well as oxidation makes it a top voice for outdoor and high-temperature applications. Its low carbon content also makes it immune to sensitization, which prevents it from forming carbide precipitation during welding. That makes it suitable for brazing, welding, and soldering as it becomes easier to work with fabricators.
Comparing 904l and 304 Stainless Steel
904L stainless steel is more expensive than 304 stainless steel but offers more resistance to pitting and crevice corrosion and also stress corrosion cracking and better weldability.
Bottom Line
When it comes to choosing between the two, several factors must be considered, such as corrosion-resistance requirements, cost-effectiveness, strength requirements, welding capability, etc. Both grades of stainless steel offer excellent formability and weldability. So make sure you consider all the factors when deciding what material will best suit your needs.
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