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Comparison of 904L Duplex Stainless Steel Tube and Austenitic Stainless Steel

In the category of stainless steel pipes and fittings, there are many types of stainless steel pipes, including 201, 301, 304, 316, 316L, 2205, and 904L… and other stainless steel pipes. Pipes of different materials have different corrosion resistance. What is the difference between 904L duplex stainless steel and austenitic stainless steel? Many people expressed their curiosity. In response to this problem, the editor of Jude has compiled some relevant materials for everyone to improve:

Let’s talk about the advantages of 904L duplex stainless steel pipe:

1. The yield strength is more than double that of ordinary austenitic stainless steel, and it has sufficient plasticity and toughness for forming requirements. The wall thickness of storage tanks or pressure vessels made of duplex stainless steel is 30-50% lower than that of commonly used austenite, which is conducive to reducing costs.

2. It has excellent resistance to stress corrosion cracking. Even the duplex stainless steel with the lowest alloy content has a higher resistance to stress corrosion cracking than austenitic stainless steel, especially in an environment containing chloride ions. Stress corrosion is a prominent problem that is difficult for ordinary austenitic stainless steels to deal with.

3. The corrosion resistance of the most commonly used 2205 duplex stainless steel in many media is better than that of ordinary 316L austenitic stainless steel, while the super duplex stainless steel has extremely high corrosion resistance, and in some media, such as acetic acid, formic acid It can even replace high-alloy austenitic stainless steel and even corrosion-resistant alloys.

4. It has good partial corrosion resistance. Compared with austenitic stainless steel with equivalent alloy content, its wear corrosion resistance and fatigue corrosion resistance are better than austenitic stainless steel.

5. The linear shrinkage coefficient of austenitic stainless steel is lower than that of austenitic stainless steel, which is close to that of carbon steel. It is suitable for connection with carbon steel and has important engineering significance, such as the production of composite plates or linings.

6. No matter under dynamic load or static load conditions, it has higher energy absorption capacity than austenitic stainless steel. This pair of structural parts has obvious advantages in dealing with sudden accidents such as collision, explosion, etc., and has practical application value.

Then talk about the defects of 904L duplex stainless steel pipe:

1. The universality and versatility of application are not as good as that of austenitic stainless steel. For example, its operating temperature must be controlled below 250 °C.

2. Its plasticity and toughness are lower than that of austenitic stainless steel, and its cold and hot working processes and forming properties are not as good as that of austenitic stainless steel.

3. There is a medium temperature brittle zone, and the process system of heat treatment and welding needs to be strictly controlled to prevent the appearance of harmful phases and damage performance.