Are you planning to work with this widely used alloy? If yes, then this guide is your essential resource.
Reading this entire article will provide you with comprehensive details about its composition, properties, and uses. It also includes information about the welding procedures and fabrication techniques associated with this versatile material.
Keep on reading!
Identifying the 304 Stainless Steel
Austenitic stainless steel is considered 304 as its top grade. This is because of its high nickel and chromium content. It also means 304 stainless steel is non-magnetic and has excellent anti-corrosion properties.
You can identify if the material is grade 304 if it has an attractive, glossy surface. Thanks to its attractiveness, it became often used in kitchenware production, chemical equipment, and so on.
In addition to being attractive steel, the 304-grade stainless steel is also easy to fabricate and has outstanding rust resistance.
The Origins
Wondering who developed the stainless steel, including the type 304 stainless steel?
A French metallurgist, Pierre Berthier, developed an iron-chromium alloy called “acier inoxydable” (stainless steel). This can be traced back to the late 19th century.
By the early 20th century –in the 1930s, the new alloy development led to the first grade of stainless steel, known as Type 304. This grade was developed for its high resistance to corrosion and heat.
Until today, it then became most preferred in many industrial and food-processing applications.
Mechanical and Physical Properties
Learning both the mechanical and physical properties of grade 304 SS before purchasing is important.
Why? This will help you ensure that the material is suitable for your ideal applications.
Mechanical Properties
| Elastic limit -ksi | 75 to 95 |
| Yield Strength -ksi | 30 |
| Elongation | 40-60% |
Physical Properties
| Density (g/cm3) | 7.93 |
| Melting Point (°C) | 1454-1493 |
| Hardness (Brinell) | 201 |
Composition
Considering the material composition can help you determine its strength and other properties.
Aside from that, it will also help you determine the likelihood of deterioration over time. Please observe its composition details below.
| Chromium | 18% |
| Nickel | 8% |
| Carbon | 0.08% |
| Manganese | 2% |
| Silicon | 0.75% |
| Phosphorus | 0.045% |
| Sulfur | 0.03% |
| Nitrogen | 0.1% |
| Iron | 0.2% |
| Niobium | 0.25% |
| Titanium | 0.1% |
Manufacturing Methods
If you are looking for the best way to manufacture 304 stainless steel, here we provide several options to process your material.
Drawing. This is a process of shaping the 304 steel by pulling it through a die. This process helps to improve strength, hardness, and wear resistance.
Cold Rolling. The process of reducing the material thickness. It is done by passing the material through two rollers with a decreasing gap between them.
Hot Rolling. Hot rolling is also a process of decreasing the material thickness further. But this time, the material is heated to a certain temperature. Before passing it through the two rollers.
Annealing and Pickling. Cleaning process of the material surface and improves its corrosion resistance. It is done by heating the material to a certain temperature. Then immerse it in an acid solution.
Passivation. The passivation manufacturing method is done by immersing the steel in an acid solution.
Polishing. The surface of the 304 stainless steel is polished to give it a smooth, attractive finish.
Laser Cutting. The laser-cutting process cuts the stainless steel with the help of a laser beam. It is a precise and fast way of cutting metal.
304 Stainless Steel Finishes
The grade 304 steel has a range of finishes that can be used to achieve a variety of looks. Whether you are looking for an elegant, more rustic, or industrial look, this selection has something to suit your needs.
Explore the various finishes to find the right one for your project.
- Polished: It is a smooth, glossy surface with a highly reflective sheen on your material.
- Brushed: The brushed is a textured finish created by using a brush to lightly abrade the surface.
- Satin: Satin is a matte finish created by using a fine abrasive.
- Mirror: A mirror is a highly reflective surface that provides a bright, reflective finish.
- Sandblasted: Sandblasted is a textured finish created by blasting the surface with fine abrasive material.
- Painted: Painted finish is applied by painting the surface with a paint or powder coating.
- Anodized: The anodized finish is an electrochemical process that creates a protective coating on the surface.
- Electropolished: Electropolish is a process that removes surface impurities and creates a smooth, shiny surface.
How to Differ 304 and 201
When you are about to choose between 304 and 201, consider each difference to help you choose which is better for your applications.
201 stainless steel has 16-18% chromium and 3-5% nickel content. It is a lower-cost option, but not as corrosion-resistant as 304. It is a good option for applications that are exposed to fresh water. As it is less likely to rust or corrode in this environment.
304 stainless steel contains 18-20% chromium and 8-10.5% nickel. It is more corrosion-resistant than 201. The most popular option for outdoor applications as it can withstand all types of weather.
So, how do they actually differ?
In terms of corrosion, grade 304 is proven much better as it has higher protection against it. Then, there will be no fear if you need the material for projects exposed to acids and other corrosive elements.
While, 201 is excellent for indoor projects, where corrosion is less likely to occur.
304 SS and 1810 SS Comparison
The key difference between these two alloys is in their composition. 304 SS is composed of 18% chromium and 8% nickel. However, 1810 is composed of 17% chromium and 10% nickel.
Which is better?
It depends on what you need the stainless steel for. 304 SS is generally known to be better for corrosion-resistant properties, while 1810 only works well for welding & forming uses.
The Similarities between 304 and 316
The two alloys, 304 and 316, are austenitic stainless steels. They are both composed of high chromium and nickel content levels. Both are also non-magnetic and can be easily welded. You can avail of them both in a wide range of shapes, sizes, and finishes.
In terms of physical properties, these two offer excellent strength and ductility. They have similar tensile strengths (70-90 KSI) and yield strengths (25-35 ksi). At temperatures below 500°F (260°C), both alloys offer excellent resistance to oxidation and corrosion.
Their properties make them suitable for a wide range of applications. They can be used in food processing, medical instruments, and chemical industries. They are also used in the manufacture of cookware and kitchen appliances.
316 and 304 Differences
In spite of similarities, there are some key differences between 316 and 304 SS. You should consider these differences before deciding which grade to use.
In terms of composition, 304 contains 18% chromium and 8% nickel. 316, on the other hand, contains 16% chromium, 10% nickel, and 2% molybdenum. The higher molybdenum content in 316 makes it more resistant to corrosion than 304. This makes it perfect for projects that may come into contact with salt water or other chemical components.
In terms of mechanical properties, type 316 offers better tensile and yield strength than 304, making it more suitable for structural applications. Additionally, 316 has higher creep resistance, which can be beneficial in applications where temperatures may rise over time.
Cost is also an important consideration when choosing between 316 and 304. The 316 is typically more expensive than the 304. But its higher cost is justified by its superior corrosion-resistant properties. In some cases, the additional cost of 316 can be offset by its long life span, making it a more cost-effective option in the long run.
Where to Apply 304 SS?
For fabricating custom parts, the 304 stainless steel is a top choice for you.
Knowing its various applications can help you make the best decision for your project. Now explore its major uses in different projects.
Food Processing Application
The 304 steel is a popular choice for equipment used in the food processing industry. This material is highly resistant to corrosion and is easy to clean and sanitize. As such, it is commonly used for:
- Storage tanks fabrication
- Mixers production
- Bowls fabrication
- Countertops
- Work surfaces
- Vats production
- Milk-processing plants
- Beer brewing equipment
- Wine-making equipment
Pharmaceutical Equipment
Type 304 is frequently used for pharmaceutical equipment due to its ease of cleaning and sterilization. This material is used for manufacturing:
- Tanks
- Piping
- Valves
- Centrifuges
- Other components in pharmaceutical processing
Kitchen Appliances
Grade 304 is a popular choice for kitchen appliances due to its durability and low maintenance requirements. This material is used for:
- Refrigerator and freezer components
- Dishwashers
- Range hoods
- Other appliances
Architectural Applications
The material is frequently used for architectural applications due to its attractive finish and strong rusting resistance. This material is commonly used for:
- Window frames
- Cladding
- Railings
Transportation
For producing components for transportation use, 304 stainless steel is a popular choice. The material is often used for producing:
- Fuel tanks
- Exhaust tanks
- Automobiles components
- Buses
- Trucks
- Other transportation equipment
The Main Varieties
The top two varieties of 304 stainless steel. These include:
- 304L
- 304H
Get to know these alloys in detail.
304L
304L contains a lower carbon amount compared to its 304 counterparts. This allows it to be used in applications where welding is required without the risk of carbide precipitation. The 304L stainless steel is also known as ultra-low carbon stainless steel. It is primarily used in applications that require welding.
304H
304H differ from 304 and 304L in terms of composition.
304H composition is carbon 0.04-0.10%, manganese 2.00%, phosphorus 0.045%, sulfur 0.030%, silicon 0.75%, chromium 18.00-20.00%, nickel 8.00-10.50%, nitrogen 0.10-0.16.
While the composition of 304L is carbon 0.035%, manganese 2.00%, phosphorus 0.045%, sulfur 0.030%, silicon 0.75%, chromium 18.00-20.00%, nickel 8.00-10.50%.
Advantages & Disadvantages
The 304 stainless steel offers a number of benefits. However, it also has some drawbacks.
Knowing these facts enables you to make the best choice for your specific application.
| Advantages | Disadvantages |
| 1. High Resistance: It is one of the most corrosion-resistant stainless steel alloys, making it more resistant to rust and oxidation than most other metals. | 1. Susceptibility to Stress Corrosion Cracking: The 304 grade can be susceptible to stress corrosion cracking in some environments, such as high chloride solutions. |
| 2. Durability: 304 stainless steel is extremely durable and can withstand harsh environments and temperatures. | 2. Low Tensile Strength: Its tensile strength is relatively low, making it more susceptible to deformation and cracking than other metals. |
| 3. Cost-Effective: The cost of 304 steel is relatively inexpensive, compared to other metals, making it a popular choice for many applications. | 3. Magnetism: Due to its high chromium and lower nickel content, 304 stainless steel is slightly magnetic. This can be an issue in some applications. |
| 4. Low Maintenance: The material requires little to no maintenance, making it ideal for use in projects where frequent maintenance is not necessary. | 4. Susceptibility to Intergranular Corrosion: The steel is susceptible to intergranular corrosion due to its high carbon content. This form of corrosion can occur when the material is exposed to high temperatures, such as when welding. |
The Standard Price
The prices can affect the profitability of businesses that rely on 304 stainless steel products.
If you are wondering what is the current standard prices today, we provide below the reference.
| Average Pricing | Current High Price | Low Pricing |
| Around $2,000 per metric ton | Approximately $2,400 per metric ton | $1.50 to $3.00 per pound, as of March 2021 |
Maximum Operating Temperature
The maximum operating temperature is around 870 °C (1600 °F).
At higher temperatures, 304 stainless steel exhibits good strength and creep resistance. Although it is not as strong as some other stainless steel alloys, this alloy is still widely used in many applications due to its good formability and cost-effectiveness.
Conclusion
All in all, 304 stainless steel is an incredibly useful and versatile material, offering excellent resistance to any corrosion elements. Its durability and strength make it an ideal choice for many items, from cutlery and kitchen appliances to manufacturing and architecture.
Only its high cost and need for regular maintenance are the drawbacks to using it. With proper maintenance, however, 304 can provide a long-lasting and reliable solution to any project.
If ever you decide to use the 304 stainless steel, Tuolian can be your partner. We can support your request orders!