AISI 304 Stainless Steel: A Complete Guide

Stainless steel is the most useful material used in many different sectors, however industries struggle to select the proper grade of stainless steel. A number of characteristics of stainless steel need to be guaranteed, including its concentration of nickel and chromium, workability, hardness, yield strength, and, most importantly, its ability to resist corrosion at all temperatures without compromising machinery performance. Because austenitic stainless steel grades, like AISI 304 stainless steel, are available in 304 sub-grades that are essential to many different industries due to their chemical makeup, they satisfy all of the aforementioned requirements. We will go over each of them with a thorough explanation of its usage and applications down below.Austenitic chromium-nickel stainless steel is known by its industry designation, AISI 304, or 18/8. The marking that reads “AISI” (American Iron and Steel Institute) indicates that stainless steel or chromium steel is available for purchase. 

What is AISI 304 Stainless Steel?

Austenitic chromium-nickel stainless steel is known by its industry designation, AISI 304, or 18/8. The marking that reads “AISI” (American Iron and Steel Institute) indicates that stainless steel or chromium steel is available for purchase.

The primary components of AISI 304 stainless steel are 18% chromium and 8% nickel. Additional alloys that improve the properties of stainless steel include nickel, manganese, silicon, nitrogen, carbon, phosphorus, and sulfur.

The AISI 304 stainless steel composition is arranged steadily, which gives it excellent corrosion resistance and longevity.

AISI 304 Stainless Steel is versatile enough to find application in a variety of industries, such as building, manufacturing, and sanitaryware, due to its ease of formation for intricate constructions.

Because of their NO-QUALITY-CHANGE corrosion resistance and lightweight nature, AISI 304 alloys are also easily welded, which makes them a popular choice for welding applications in industries including metal sheeting, wire mesh products, and steam piping.

The Three Primary Grades of 304 Stainless Steel:

304L Stainless Steel:

Now, what does the letter “L” in 304L mean, and how does it affect everything?

The grade “L” stands for “Low-carbon,” and it differs from AISI 304 Stainless Steel in a minor but noteworthy way—its carbon content is 0.05% lower. This means that it is structurally weaker.

This is not to say that 304L cannot be used in any industrial setting; in fact, it is widely regarded as being far more beneficial than other grades of stainless steel since it reduces carbide precipitation, even in extremely corrosive conditions, making welding much simpler.

Applications of 304L Stainless Steel:

Welding industry

Heat exchangers

Dyeing industry

Chemical containers

Welded screens for mining

304H Stainless Steel:

The letter “H” in 304H stands for “High” carbon content, indicating a higher strength while dealing with high temperatures. The most extensively utilized grades of stainless steel worldwide, when it comes to industrial applications, are 304 and 304H.

304H stainless steel has excellent strength at temperatures ranging from 550°C to 800°C, making it the ideal choice for high-temperature applications. Because of its strong oxidation resistance, stainless steel 304H is perfect for continuous service up to 925°C and occasional use at 870°C.

Applications of 304H Stainless Steel:

Electric generation plants

Condensers

Boilers

Heat exchangers

Steam exhausts

304LN Stainless Steel:

Strengthening of yield, increased nitrogen content!

This word alone is the source of the stainless steel grade 304LN. In essence, 304LN is an austenitic type of stainless steel that has a nitrogen boom. It provides a greater yield strength without sacrificing its adaptability.

This grade can withstand temperatures as high as 1000°C to 1100°C with ease, making it more stable than 304L for martensitic transformations brought on by low temperatures. 

Applications of 304LN Stainless Steel:

Food industry

Chemical industry

Fabrication industry

Nuclear industry

Petroleum industry

AISI 304 Stainless Steel Characteristics:

AISI 304 Stainless Steel Machinability:

The ability of a material to be cut or molded with quality that satisfies smooth surface finishing and long-term machinability is known as machinability, and stainless steel is no exception.

According to American Iron and Steel Institute standards, AISI 304 has a machinability score of 70, which is the same as AISI 304L. 

AISI 304 Stainless Steel Hot Working: 

Temperatures up to 870 degrees Celsius are suitable for AISI 304 stainless steel due to its great resistance to oxidation and heat. 

It is not advised to use these high temperatures frequently, particularly when there is moisture present. The workability and corrosion resistance efficiency of AISI 304 stainless steel might be significantly reduced by this mismatch. 

AISI 304 Stainless Steel Corrosion Resistance:

With its primary attribute of easy resistance to chloride and simulation of circumstances, 304 stainless steel is the most widely chosen type of stainless steel. 

While AISI 304 stainless steel can be easily annealed to improve workability and yield strength, heat treatments cannot effectively harden stainless steel 304.

AISI 304 Stainless Steel Fabrication:

Although stainless steel is utilized to prevent corrosion, keep in mind that improper fabrication will result in unsatisfactory outcomes.

Therefore, care must be taken to prevent corrosion resistance. Before being used in fabrication, stainless steel should only be cleaned and worked with specifically designed materials.

AISI 304 Stainless Steel Welding:

304 stainless steel welds well both with and without fillers, depending on the situation.

It is advised to use grade 308 stainless steel electrodes and filler rods for stainless steel 304. Post-weld annealing could be necessary for heavy welded sections, like the splices on transfer girders.

AISI 304 Stainless Steel Applications:

Offshore Technology

Chemical Industry

Bridges

Medical Industry

Power Plants

Shipbuilding Industry

Fasteners and flange Manufacturing

About SteelAge Alloys LLP.

Global demand for stainless steel is rising, as we have seen through our blog, and SteelAge Alloys LLP produces corrosion-resistant, robust, and low-maintenance stainless steel bright bars that can be used for both domestic and industrial purposes.

SteelAge Alloys LLP is a leading manufacturer of stainless steel products, including stainless steel bright round bars, hexagonal bars, square bars, precision bars, polished bars, hardened bars, cold drawn bars, and wires. Our bright stainless steel bars are processed using the most up-to-date technology to ensure high surface smoothness and quality assurance.

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