In the world of stainless steel, 304 and 304L materials are undoubtedly star products and are widely used in many fields. Although their names differ by just one letter, there are subtle differences in ingredients, properties, and applications.

1.Differences in ingredients

304 stainless steel is a general-purpose stainless steel material. Its main alloying elements are chromium (Cr) and nickel (Ni). It is usually called 18-8 stainless steel because its chromium content is about 18% and nickel content is about 8 %. This material has good corrosion resistance and formability, so it is widely used in various fields.

304L stainless steel is obtained by reducing the carbon (C) content on the basis of 304. Generally speaking, the carbon content of 304L stainless steel is controlled below 0.03%, while the carbon content of 304 stainless steel is higher. This low-carbon design gives 304L stainless steel better resistance to intergranular corrosion during welding.

2.Differences in performance

Due to differences in composition, 304 and 304L stainless steel also show certain differences in performance. First of all, in terms of corrosion resistance, although both have good corrosion resistance, 304L stainless steel has better corrosion resistance after welding. This is because low-carbon 304L stainless steel can reduce the risk of intergranular corrosion during the welding process, thereby improving the corrosion resistance of the welded joint.

Secondly, in terms of mechanical properties, due to the difference in carbon content, the strength, hardness and other mechanical properties of 304 and 304L stainless steel are also different. Generally speaking, the strength and hardness of 304 stainless steel is higher than that of 304L stainless steel, but in some applications that require lower strength and better toughness, 304L stainless steel has more advantages.

3.Differences in application

It is precisely due to the differences in composition and performance that 304 and 304L stainless steel also have different application fields. 304 stainless steel is widely used in food processing equipment, medical equipment, architectural decoration, auto parts and other fields due to its good corrosion resistance and formability. Its higher strength and hardness also allow it to be used in some situations that require higher material strength.

304L stainless steel is more suitable for occasions that require higher welding performance. For example, in areas such as large building structures, chemical equipment, oil and gas pipelines that require a large amount of welding, 304L stainless steel can better ensure the corrosion resistance and stability of welded joints. In addition, in some applications that require higher material toughness, such as equipment manufacturing in low-temperature environments, 304L stainless steel also has advantages.

To sum up, although there is only one word difference between 304 and 304L stainless steel, there are significant differences in composition, performance and application. When selecting materials, we need to choose appropriate materials based on specific application scenarios and needs. For example, when the requirements for material strength and hardness are high, 304 stainless steel can be selected; and when welding performance and toughness are required, 304L stainless steel can be selected.