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Outokumpu's new Acom issue focuses on duplex stainless steel in fire

Time:[4/6/2012]   Hits:2089
Acom is Outokumpu's scientific magazine about stainless steel. The new Acom issue discusses duplex stainless steel in fire.

The increased use of duplex materials in load carrying applications where there is a risk of fire, such as buildings, tunnels and bridges, led to the generation of data for fire design that is described in this issue of Acom.

LDX 2101®, 2304, LDX 2404® and 2205 have been tested to generate data for fire design. 2205 is the only grade included in Eurocode 3, so far and the testing shows that the present values for 2205 are too high, even though all duplex grades showed good fire properties. The retention factors of the duplex grades are lower at the higher temperatures compared to standard austenitic grades, but the higher room temperature strength still gives a higher strength in fire up to 700-800°C. 2304 has lower fire resistance properties compared to LDX 2101®, LDX 2404® and 2205.

The Young's modulus of stainless steel decreases less with temperature compared to carbon steel, and this may in many cases be as important as the proof strength decrease for the fire design.

As a result of the data in this work a new proposal for Eurocode 3 has been presented, resulting in two duplex groups Duplex I and Duplex II.