Benefits of Duplex Stainless Steel Pipes:
- Corrosion Resistance:
Duplex SS contains about 20% of chromium in addition to the molybdenum content. Together, these elements make duplex stainless steel grades extremely resistant to severely corrosive environments. Duplex and Super duplex grades of stainless steel can withstand crevice, pitting, chloride ion, and stress corrosion even at elevated temperatures.
- Machining Properties:
Duplex Stainless Steel grades have great fatigue strength and superior mechanical properties.
- Heat resistant and hot-working range:
Duplex stainless steel grades are resistant to heat and high-temperature environments. Duplex Steel UNS S31803 Pipes and Tubes do not necessarily require forging, they can be rolled directly. However, in high heat environments, it is tougher to work with chromium alloys than austenitic alloys. Thus, it is easier to hot-roll duplex SS pipes that have low chromium content.
Duplex SS grades have superior weldability. These pipes do not crack easily under pressure and heat influence. Preheating the material before the welding process is not required in the case of Duplex SS Pipes.
- Thermal Conductivity and Expansion:
When Duplex SS pipes are compared to austenitic grades of SS pipes such as 304 and 316, it is observed that Duplex pipes have proven to have better thermal conductivity with a lower rate of expansion. This property of incredible thermal conductivity makes Duplex SS pipes appropriate for applications in composite plating and as the core element in a heat exchanger.
Disadvantages or Banes of Duplex SS Pipes:
Just like any other piping material, Duplex SS grades also have their downsides.
- Its lower heat resistance compared to austenite grades is one of the major downsides of duplex SS pipes.
- Duplex SS pipes are restricted to sustained applications only in temperatures below 300 degrees centigrade.
- Welding, machining, and processing Duplex Stainless steel pipes are complex and tougher than of Austenitic SS pipes.