304 Stainless Steel

Overview

304 stainless steel, known as SUS304 in Japan, is a versatile material produced according to American ASTM standards. It is equivalent to China’s 06Cr19Ni10 (formerly 0Cr18Ni9).

Characteristics

Anti-rust Properties: 304 stainless steel offers stronger anti-rust properties than 200 series stainless steel.
Corrosion Resistance: It has excellent resistance to stainless corrosion and intergranular corrosion. In oxidizing acids like nitric acid, 304 stainless steel remains resistant below the boiling point at concentrations ≤65%. It also resists alkaline solutions and most organic and inorganic acids.
High Temperature Resistance: It can withstand temperatures up to 1000-1200 degrees Celsius.

Chemical Composition

Old Grade (0Cr18Ni9):
- Carbon (C): 0.07%
- Silicon (Si): 0.030%
- Manganese (Mn): 2.00%
- Phosphorus (P): 0.035%
- Sulfur (S): 0.030%
- Nickel (Ni): 8.00-11.00%
- Chromium (Cr): 17.00-20.00%
New Grade (06Cr19Ni10):
- Carbon (C): 0.08%
- Silicon (Si): 1.00%
- Manganese (Mn): 2.00%
- Phosphorus (P): 0.045%
- Sulfur (S): 0.030%
- Nickel (Ni): 8.00-11.00%
- Chromium (Cr): 18.00-20.00%

The new grade has a slightly higher chromium content and relaxed phosphorus limits, making it the same as TP304.

Density

The density of SUS304 stainless steel is 7.93 g/cm³.

Applications

304 stainless steel is used in various applications due to its excellent properties:

Food Equipment: Widely used in the food industry.
Chemical Equipment: Suitable for general chemical equipment.
Atomic Energy Equipment: Used in components for the atomic energy industry.
Heat-Resistant Parts: Ideal for making parts requiring good performance at high temperatures.
Other Uses: Common in deep-drawn components, acid pipelines, containers, vehicles, auto parts, household appliances, and as core material for welding chromium-nickel stainless steel.

Summary

304 stainless steel is the most widely used grade among austenitic stainless steels due to its excellent corrosion resistance, high-temperature resistance, and good mechanical properties. Its applications span from food equipment to the atomic energy industry, highlighting its versatility and reliability.