Element Content, Application Field and Advantage Analysis of Stainless Steel 904L

Stainless steel 904L is a super austenitic stainless steel, which is widely used in chemical industry, petroleum industry, paper industry, pharmaceutical industry, and food and beverage production. The excellent performance and wide application scenarios of this material benefit from its special chemical element content and unique material properties.

1. Element content of stainless steel 904L

The main element content of stainless steel 904L is as follows:

Chromium (Cr): 19.0% - 23.0%

Nickel (Ni): 23.0% - 28.0%

Copper (Cu): 1.0% - 2.0%

Molybdenum (Mo): 4.0% - 5.0%

Iron (Fe): balance

Carbon (C): ≤0.02%

Manganese (Mn): ≤2.0%

Silicon (Si): ≤1.0%

Phosphorus (P): ≤0.045%

Sulfur (S): ≤0.035%

Boron (B): 0.005% - 0.05%

Among them, the content of chromium and nickel is relatively high, which makes stainless steel 904L have good corrosion resistance. The addition of molybdenum and copper further improves the corrosion resistance of the material in strong acid environments.

2. Mechanical properties

The mechanical properties of stainless steel 904L depend on its composition and heat treatment. In the unheated state, the strength of 904L is low, but its plasticity and toughness are strong. After heat treatment, the strength of 904L is significantly improved, but its plasticity and toughness are reduced.

The typical mechanical properties of stainless steel 904L are as follows:

Tensile strength: 900 MPa

Yield strength: 650 MPa

Elongation: 20%

Section reduction rate: 50%

3. Application fields of stainless steel 904L

Due to the excellent corrosion resistance of 904L, it is widely used in many fields:

1. Chemical industry: stainless steel 904L has strong corrosion resistance to strong acid and strong alkali, so it is widely used in chemical industry, especially in acid and alkali equipment.

2. Oil and natural gas industry: In the environment containing sulfur, the corrosion resistance of 904L exceeds that of ordinary austenitic stainless steel, so it has been widely used in the oil and natural gas industry.

3. Papermaking industry: In the papermaking process, sulfate and chloride have a corrosive effect on equipment, and the corrosion resistance of 904L makes it widely used in this field.

4. Pharmaceutical industry: In the pharmaceutical process, a large number of chemical substances are used, some of which are corrosive. The corrosion resistance of 904L allows it to be used in pharmaceutical equipment.

5. Food and beverage production: 904L is not only corrosion-resistant, but also has good mechanical properties and welding properties, so it is also widely used in food and beverage production equipment.

4. Advantages of stainless steel 904L

1. Super corrosion resistance: Due to the high content of chromium, nickel, molybdenum and copper, 904L has strong corrosion resistance to most organic and inorganic acids, especially to acids containing chloride.

2. Good welding performance: 904L has a small thermal expansion coefficient, so it has good welding performance during the welding process, and the welded joint is not easy to crack.

3. Excellent mechanical properties: 904L has good toughness, and its tensile strength and yield strength are much higher than ordinary austenitic stainless steel, so that it can show excellent performance under various harsh working conditions .

4. Good impact resistance: In low temperature environment, the impact resistance of 904L is still very good, which makes it able to show excellent performance in low temperature environment.

5. Excellent wear resistance: 904L has high hardness and good wear resistance, which makes it perform well in high-speed, high-pressure, and high-wear environments.

6. High temperature stability: 904L has good high temperature stability and can work in the temperature range of 425°C-1300°C.

In general, the unique element content of stainless steel 904L makes it have super corrosion resistance, good welding performance and mechanical properties, as well as excellent wear resistance and high temperature stability. These unique properties make it widely used in chemical industry, petroleum industry, paper industry, pharmaceutical industry, and food and beverage production. However, although stainless steel 904L has advantages in many aspects, its cost is higher than other stainless steel materials, so the choice needs to be weighed according to actual needs and economic considerations.