Alloy 800HT
Equivalent designations
UNS N08811
DIN W. Nr. 1.4959
Form
ASTM
Rod and bar
B 408
Plate, sheet and strip
A 240, A 480, B 409, B 906
Seamless pipe and tube
B 407, B 829
Welded pipe
B 514, B 775
Welded tube
B 515, B 751
Welding fitting
B 366
Forging
B 564
Chemical composition
%
Fe
Ni
Cr
C
Mn
Si
S
Cu
Al
Ti
Al+Ti
min
39.5
30.0
19.0
0.06
0.15
0.15
0.85
max
35.0
23.0
0.10
1.50
1.00
0.015
0.75
0.60
0.60
1.20
Physical properties
Density
7.94 g/cm3
Melting range
1357-1385℃
Features: Incoloy 800HT ensures higher stress rupture and creep properties compared to Incoloy 800H as a result of restricting the carbon content further in the range of 0.06 to 0.10% (Incoloy 800H is 0.05 to 0.10%), and the aluminum plus titanium content at 0.85 to 1.20% (Incoloy 800H is 0.30 to 1.20%).
Applications: Chemical and petrochemical process piping, high temperature heat exchangers, furnace components, carburizing equipment, heating-element sheathing, and nuclear power steam superheating tubing.