Comparison of Duplex Stainless Steel Pipe and Austenitic Stainless Steel Pipe

The Duplex Stainless Steel Pipe is half of the ferrite phase and the austenite phase in its solidified structure, and the minimum phase content may be as high as 30%. Due to the characteristics of the two-phase structure, DSS combines the advantages of ferritic stainless steel and austenitic stainless steel by properly controlling the chemical composition and heat-treatment process. As a Nickel Alloy Pipe Factory, let's explain it to everyone.

Compared to the Austenitic Stainless Steel Pipe, the advantages of duplex stainless steel are as follows:

(1) The yield strength is more than twice that of ordinary austenitic stainless steel, and it has sufficient plastic toughness required for molding. The thickness of the tank or pressure vessel made of duplex stainless steel is 30-50% lower than that of the commonly used austenite, which is beneficial to reduce the cost.

(2) It has excellent resistance to stress corrosion cracking, and even the duplex alloy with the lowest alloy content has a higher resistance to stress corrosion cracking than austenitic stainless steel. Especially in environments containing chloride ions. Stress corrosion is a prominent problem that is difficult to solve in ordinary austenitic stainless steels. (3) The most common 2205 duplex stainless steel used in many media has better corrosion resistance than ordinary 316L austenitic stainless steel, while the Super Duplex Stainless Steel Pipe has extremely high corrosion resistance. In some media, such as acetic acid, formic acid, etc. can even replace high-alloy austenitic stainless steel and even corrosion-resistant alloys.

(4) It has good local corrosion resistance and is superior to austenitic stainless steel in corrosion resistance and fatigue corrosion resistance compared with austenitic stainless steel with equivalent alloy content.

(5) The austenitic stainless steel has a low coefficient of linear expansion and is close to carbon steel. It is suitable for connection with carbon steel and has important engineering significance, such as producing composite plates or linings.

(6) It has higher energy absorption capacity than austenitic stainless steel under dynamic or static load conditions, and this pair of structural parts can cope with unexpected accidents such as collision. The advantages of duplex stainless steel are conspicuous and have practical application value.

Duplex Stainless Steel Pipe

Compared with the Austenitic Stainless Steel Pipe, the weakness of duplex stainless steel is as follows:

(1) The universality and versatility of the application are not as good as that of austenitic stainless steel. For example, its use temperature must be controlled below 250 degrees Celsius.

(2) Its plastic toughness is lower than that of austenitic stainless steel, cold, hot processing and forming properties are not as good as austenitic stainless steel.

(3) There is a medium-temperature brittle zone, and the processing system of heat treatment and welding needs to be strictly controlled to avoid the appearance of harmful phases and impair performance.