Stainless steel (SS) is widely used in many industries because of its high corrosion resistance, high durability and good appearance. Out of all the stainless steel, two types are most popular and that is Stainless Steel 304 and Stainless Steel 304L. Although they have many similar characteristics, certain differences define whether one should use one or the other. In this blog, you will learn about the differences between SS 304 seamless pipes and SS 304L pipes in order to make the right choice for your projects.
Difference Between SS 304 Seamless Pipes and SS 304L Pipes
1. Composition and Chemical Differences
The primary distinction between 304 SS Seamless Pipe and SS 304L pipe lies in their carbon content:
- SS 304: Has a higher level of carbon content up to 0.08%.
- SS 304L: The “L” is for low carbon, and this grade contains a maximum of 0.03% carbon.
This lower carbon content in 304L SS Pipe makes it more resistant to carbide formation during welding and thus minimizing the chances of corrosion in the affected zones.
2. Corrosion Resistance
Corrosion resistance of both stainless steel 304 seamless pipe and SS 304L pipe is very good but SS 304L is slightly better in some applications. The decrease in carbon content makes SS 304L pipes more immune to intergranular corrosion, especially in areas where the metal is used at high temperatures, for example, during welding. Hence, 304L SS pipes are used in those applications where welding is more frequent and for a higher number of times.
But in most of the usual applications where there is no severe welding involved, the corrosion resistance of both the SS 304 seamless pipes and SS 304L pipe are almost the same.
3. Mechanical Strength
SS 304 has higher carbon content than SS 304L, as a result, the tensile strength of SS 304 seamless pipe is higher to that of SS 304L pipes. This makes the SS 304 seamless pipes more suitable for use in environments where mechanical properties are of paramount importance. However, SS 304L pipes has slightly lower carbon content and are thus slightly softer and may not be suitable for use where high strength is a vital factor. The difference in strength is rather small and does not influence the performance, if the materials are used for general purposes.
4. Weldability
The weldability of the SS 304L pipe is better than the SS 304 seamless pipe because it contains a lesser percentage of carbon. In welding, carbon content in SS 304 is higher, leading to carbide precipitation, and corrosion around the weld area, especially in environments with high corrosive content. This risk is also greatly reduced in SS 304L because it has a lower carbon content than SS 304 and thus is a better pipe for welded structures.
5. Cost Considerations
The price difference between SS 304 and SS 304L pipes is not very significant. SS 304L pipe can sometimes be slightly pricier than 304 Stainless steel seamless pipe because it has better corrosion properties in certain environments and there is a higher demand for welding operations. Where there is not much welding involved, the SS 304 seamless pipes can be a cheaper substitute with required strength and corrosion resistance.
Conclusion
Thus, both SS 304 and SS 304L seamless pipes have their own benefits that are associated with the needs of a particular project. SS 304 pipes provide improved mechanical properties for structural applications while 304L SS pipes are generally used for applications involving heavy welding because of its lower carbon content and superior resistance to corrosion in the post weld heat affected zones.
In this case, when comparing between the two, it will be important to look at some factors like weldability, strength, and the surrounding environment of the project.
