1.4404 vs. 1.4571

Attribute	1.4404	1.4571
Chemical Composition	16-18% Cr, 10-13% Ni, 2% Mo	16-18% Cr, 10-13% Ni, 2% Mo
Corrosion Resistance	Good	Excellent
Strength	Good	Higher
Heat Resistance	Good	Good

Introduction

Stainless steel is a popular material in various industries due to its corrosion resistance, durability, and aesthetic appeal. Two common grades of stainless steel are 1.4404 and 1.4571. In this article, we will compare the attributes of these two grades to help you understand their differences and applications.

Chemical Composition

1.4404 stainless steel, also known as AISI 316L, contains 16-18% chromium, 10-14% nickel, 2-3% molybdenum, and less than 0.03% carbon. On the other hand, 1.4571 stainless steel, also known as AISI 316Ti, contains 16-18% chromium, 10-14% nickel, 2-3% molybdenum, and 0.08-0.10% carbon. The higher carbon content in 1.4571 provides better resistance to intergranular corrosion compared to 1.4404.

Corrosion Resistance

Both 1.4404 and 1.4571 stainless steel grades offer excellent corrosion resistance in a wide range of environments, including acidic and chloride-rich conditions. However, 1.4571 is specifically designed to provide superior resistance to intergranular corrosion, making it suitable for applications where exposure to high temperatures and corrosive substances is common.

Strength and Toughness

1.4404 and 1.4571 stainless steel grades have similar mechanical properties, including high tensile strength, good toughness, and excellent formability. However, the higher carbon content in 1.4571 enhances its strength and hardness, making it more suitable for applications that require increased mechanical performance.

Heat Resistance

Both 1.4404 and 1.4571 stainless steel grades exhibit good heat resistance, allowing them to maintain their mechanical properties at elevated temperatures. However, 1.4571 is more resistant to sensitization and carbide precipitation at high temperatures, making it a preferred choice for applications involving prolonged exposure to heat.

Weldability

1.4404 and 1.4571 stainless steel grades are both easily weldable using common welding techniques such as TIG, MIG, and arc welding. However, the higher carbon content in 1.4571 may result in increased susceptibility to weld decay and reduced corrosion resistance in the heat-affected zone. Proper welding procedures and post-weld treatments are essential to maintain the integrity of the material.

Applications

1.4404 stainless steel is commonly used in industries such as food processing, pharmaceuticals, marine engineering, and chemical processing due to its excellent corrosion resistance and formability. On the other hand, 1.4571 stainless steel is preferred in applications where resistance to intergranular corrosion and high temperatures is critical, such as in heat exchangers, exhaust systems, and pressure vessels.

Conclusion

In conclusion, both 1.4404 and 1.4571 stainless steel grades offer excellent corrosion resistance, strength, and heat resistance for a wide range of applications. While 1.4404 is a versatile grade suitable for general-purpose use, 1.4571 provides enhanced resistance to intergranular corrosion and high temperatures, making it ideal for specialized applications. Understanding the differences between these two grades will help you choose the right material for your specific requirements.