Super Duplex VM 25S 80 is a Corrosion Resistant Alloy. It is called "Super Duplex" because of its improved corrosion resistance to H2S. It is iron based plus main alloying elements Cr, Ni and Mo. The PRE is above 40. Structure is Duplex (austenite and ferrite). VM 25S 80 is delivered in solution annealed conditions.
VM 25S 80 is recommended when pCO2 is above 2psi / 0.14bar and high temperature up to 482°F / 250°C. Chlorine is limited to 120,000ppm. It can be used with some amount of H2S (3psi – 0.2bar). Partial pressure H2S acceptable is governed by temperature.
VM 25S 80 can be used as tubing or casing.
VM 25S 80 has been tested from room to high temperature for SCC and SSC with different levels of H2S.
Typical Chemical composition
PRE=Pitting Resistance Equivalent = %Cr + 3.3 %Mo + 1.65 % W + 16 % N
Density = 7.81kg/dm3
In solution annealed condition
Control hardness through wall
Physical properties & evolution with temperature
The product is used in the following areas:
Avoid pollution by contact from carbon or low alloy steel (pipe or parts).
Avoid atmospheric pollution with iron (e.g. concrete plant).
Please refer to the VAM® BOOK