What are the differences between stainless steel 304, 304L, 316, and 316L
Stainless steel is a material that we come into contact with a lot in our daily lives, and stainless steel is also widely used in heavy industry, light industry, construction, and other industries. Stainless acid-resistant steel is referred to as stainless steel. It is composed of two parts: stainless steel and acid-resistant steel. In short, steel that can resist atmospheric corrosion is called stainless steel, while steel that can resist chemical medium corrosion is called acid-resistant steel. Commonly used types of stainless steel are 304, 304L, 316, and 316L, which are the 300 series of austenitic stainless steel. What do 304, 304L, 316, and
316L mean?
304 stainless steel: 304 stainless steel is a common and widely used steel type with good corrosion resistance, heat resistance, low-temperature strength, and mechanical properties; good processing performance and high toughness. It is widely used in the production of equipment and parts that require good comprehensive performance (corrosion resistance and formability). It is resistant to corrosion in the atmosphere. If it is an industrial atmosphere or a heavily polluted area, it needs to be cleaned in time to avoid corrosion. 304 stainless steel is a nationally recognized food-grade stainless steel.
316 stainless steel: The main difference in chemical composition between 316 and 304 is that 316 contains Mo, and it is generally recognized that 316 has better corrosion resistance and is more resistant to corrosion than 304 in high-temperature environments. It can be used under harsh high-temperature conditions; has good work hardening properties (weak or non-magnetic after processing); is non-magnetic in solid solution state; and has good welding performance. It is widely used in chemical, dye, papermaking, oxalic acid, fertilizer and other production equipment, food industry, coastal area facilities, etc.
The "L" in the grade: We all know that stainless steel contains a variety of elements and metals with a reduced carbide content than normal and will be
represented by an "L" after the grade - such as 316L, and 304L.
Why reduce carbides? Mainly to prevent "intergranular corrosion". Intergranular corrosion refers to the precipitation of carbides in metal during high- temperature welding. Intergranular corrosion destroys the bond between grains and greatly reduces the mechanical strength of the metal. The metal surface is often still intact, but it cannot withstand knocking, so it is a very dangerous corrosion.
304L stainless steel: As a low-carbon 304 steel, its corrosion resistance is similar to that of 304 steel under normal conditions, but after welding or stress relief, its resistance to intergranular corrosion is excellent; without heat treatment, It can maintain good corrosion resistance and can be used at -196°C~800°C.
316L stainless steel: As a low-carbon series of 316 steel, in addition to having the same characteristics as 316 steel, it has good resistance to intergranular corrosion. It can be used in products with high requirements for resistance to intergranular corrosion, as well as outdoor machines in the chemical, coal, and petroleum industries, chemical plants, and other fields. A higher susceptibility to intergranular corrosion does not mean that non-low-carbon materials are more susceptible to corrosion. This sensitivity is also higher in high chlorine environments. The Mo content of 316L makes this steel type have good resistance to pitting corrosion and can be safely used in environments containing halogen ions such as C-.
The sintered stainless steel filter element has precise ventilation pores, consistent size, and even distribution; good air permeability, fast gas and liquid circulation, and even and dense distribution; available in a variety of sizes and structural types, and can also be customized according to needs; stainless steel threaded part The part is seamlessly integrated with the breathable shell part, which is firm and beautiful. It can also have threads directly built into the breathable shell, giving it a fully breathable appearance without additional solid accessories.
316L mean?
304 stainless steel: 304 stainless steel is a common and widely used steel type with good corrosion resistance, heat resistance, low-temperature strength, and mechanical properties; good processing performance and high toughness. It is widely used in the production of equipment and parts that require good comprehensive performance (corrosion resistance and formability). It is resistant to corrosion in the atmosphere. If it is an industrial atmosphere or a heavily polluted area, it needs to be cleaned in time to avoid corrosion. 304 stainless steel is a nationally recognized food-grade stainless steel.
316 stainless steel: The main difference in chemical composition between 316 and 304 is that 316 contains Mo, and it is generally recognized that 316 has better corrosion resistance and is more resistant to corrosion than 304 in high-temperature environments. It can be used under harsh high-temperature conditions; has good work hardening properties (weak or non-magnetic after processing); is non-magnetic in solid solution state; and has good welding performance. It is widely used in chemical, dye, papermaking, oxalic acid, fertilizer and other production equipment, food industry, coastal area facilities, etc.
The "L" in the grade: We all know that stainless steel contains a variety of elements and metals with a reduced carbide content than normal and will be
represented by an "L" after the grade - such as 316L, and 304L.
Why reduce carbides? Mainly to prevent "intergranular corrosion". Intergranular corrosion refers to the precipitation of carbides in metal during high- temperature welding. Intergranular corrosion destroys the bond between grains and greatly reduces the mechanical strength of the metal. The metal surface is often still intact, but it cannot withstand knocking, so it is a very dangerous corrosion.
304L stainless steel: As a low-carbon 304 steel, its corrosion resistance is similar to that of 304 steel under normal conditions, but after welding or stress relief, its resistance to intergranular corrosion is excellent; without heat treatment, It can maintain good corrosion resistance and can be used at -196°C~800°C.
316L stainless steel: As a low-carbon series of 316 steel, in addition to having the same characteristics as 316 steel, it has good resistance to intergranular corrosion. It can be used in products with high requirements for resistance to intergranular corrosion, as well as outdoor machines in the chemical, coal, and petroleum industries, chemical plants, and other fields. A higher susceptibility to intergranular corrosion does not mean that non-low-carbon materials are more susceptible to corrosion. This sensitivity is also higher in high chlorine environments. The Mo content of 316L makes this steel type have good resistance to pitting corrosion and can be safely used in environments containing halogen ions such as C-.
The sintered stainless steel filter element has precise ventilation pores, consistent size, and even distribution; good air permeability, fast gas and liquid circulation, and even and dense distribution; available in a variety of sizes and structural types, and can also be customized according to needs; stainless steel threaded part The part is seamlessly integrated with the breathable shell part, which is firm and beautiful. It can also have threads directly built into the breathable shell, giving it a fully breathable appearance without additional solid accessories.
