Metals

Nickel Alloy 800H/HT in Sheet, Plate, and Profiles

SPECIFICATIONS: GRADE Alloy 800H/HT | UNS N08811 | ASTM/ASME B409 / B408 | Werkstoff 1.4876

Castle Metals supplier a wide range of Alloy 800 sheet and plate from their facility in the UK, with various added value processing including water jet, laser, plasma and hi definition plasma, Castle are able to profile to any shape or size to meet customers specific requirements. All material kept by Castle Metals is certified to the highest industry standards used in some of the most demanding environments in the world.

 

Chemical Composition (average %)

Alloy 800H Ni Cr Fe C Mn Si Cu P S Al Ti Al+Ti
Min 30.0 19.0 bal. 0.06 0.5 0.2 - - - 0.20 0.20 -
Max 32.0 22.0 0.08 1.0 0.6 0.5 0.015 0.010 0.40 0.50 0.7

 

Alloy 800HT Ni Cr Fe C Mn Si Cu P S Al Ti Al+Ti
Min 30.0 19.0 bal. 0.06 0.5 0.2 - - - 0.30 0.30 0.85
Max 32.0 22.0 0.10 1.0 0.6 0.5 0.015 0.010 0.60 0.60 1.2

Metallurgical Structure

Alloy 800H and alloy 800HT are austenitic, solid solution alloys containing small amounts of precipitated titanium nitride and carbide, carbonitrides and chromium carbide.

During long-term exposure of alloy 800H to temperatures below 700°C (1290°F) γ’-phase may be formed which lowers the ductility.

Alloy 800HT precipitates γ’-phase combined with a loss of ductility.

Corrosion Resistance

The high nickel and chromium contents of alloy 800H and alloy 800HT ensure excellent resistance to oxidation. The alloys are also very resistant to carburisation, nitriding and oxidising sulphur-bearing atmospheres. The protective oxide film which is formed is adherent in both static and cyclic conditions of heating and cooling, and resistance to carburisation is enhanced when a thin film of oxide is first formed on the alloy. Resistance to hydrogen is excellent and alloy 800H and alloy 800HT are standard materials used in the production of hydrogen in steam/hydrocarbon reforming processes.

Designation and Standards – Alloy 800H

Country
National
Standards
Material
Designation
Specification
Chem.
Compo-
sition
Tube & Pipe Sheet
&
Plate
Rod
&
Bar
Strip Forgings
Seamless Welded
France
AFNOR
               
Germany
DIN (Provisional)
VdTÜV
W.-Nr .1.4958
X5NiCrAITi3120
17459/460
412/434
17459
412/434
  17460
412/434
17460
412/434
17460
412/434
17460
412/434
United
Kingdom
BS
NA 15 (H)   3074   3072 3076 3073  
USA
ASTM
ASME
UNS N08810   B407
SB407
B163
B514/515
SB163/
514/515
B409
SB409
B408
SB408
B409
SB409
B564
SB564
ISO MC-FeNi32Cr21AITi              

Designation and Standards – Alloy 800HT

Country
National
Standards
Material Designation Specification
Chem.
Compo-
sition
Tube & Pipe Sheet
&
Plate
Rod
&
Bar
Strip Forgings
Seamless Welded
France
AFNOR
               
Germany
DIN (Provisional)
VdTÜV
W.-Nr .1.4959
X8NiCrAITi32 21
17459/460 17459   17460 17460 17460 17460
United
Kingdom
BS
               
USA
ASTM
ASME
UNS N08811   B407
SB407
B163
SB163
B409
SB409
B408
SB408
B409
SB409
B564
SB564
ISO                

The following properties are applicable to the solution-treated condition and the indicated size ranges. Material outside these size ranges is subject to special enquiry. The values are valid for longitudinal and transverse specimens.

Sheet and strip up to 3mm 1/8″
Sheet and plate up to 50mm 2″
Tube up to 200mm dia 8″ dia
Rod and bar , forgings up to 250mm 10″

Temp. Tensile
Strength
0.2% Yield
Strength
1.0% Yield
Strength
Elongation
A5%
°C °F N/mm2 Ksi N/mm2 Ksi N/mm2 Ksi
RT RT 500 72.5 170 24.7 200 29.0 Transverse 30
Longitudinal 35
93 200 - - 141 20.4 161 23.3  
100 212 <425> - 140 20.3 160 23.2  
200 392 <400> - 115 16.7 135 19.6  
204 400 - - 113 16.4 133 19.3  
300 572 <390> - 95 13.8 115 16.7  
316 600 - - 93 13.5 113 16.4  
400 752 <360> - 80 11.6 100 14.5  
538 1000 - - 77 11.2 97 14.1  
593 1100 - - 75 10.9 95 13.8  
600 1112 <300> - 75 10.9 95 13.8  

170… according to VdTÜV no.412 and 434 and converted (N/mm2 x 0.145=ksi) 141… values determined by graphs/diagrams <> informative only minimum short-time mechanical properties of alloy 800H at room and elevated temperatures according to VdTÜV data sheets 412 and 434.

Please Note: The figures quoted are intended for guidance only. For further information, please refer to the standards listed or contact our sales or QA department.

Due to high strength during long periods of service and resistance to carburisation and nitriding, alloy 800H and 800HT have found many applications in steam/hydrocarbon reforming, for components such as: pigtails, headers/collectors/manifolds, transfer piping, catalyst tubes (in low-pressure processes) and quench-system piping.

Typical applications include:

  • Ethylene pyrolysis tubing in convection and radiant sections – resistance to carburisation and good mechanical properties
  • Ethylene dichloride cracking tubes – resistance to carburisation and to dry hydrogen chloride and chlorine
  • Cracking tubes used in the production of acetic anhydride and ketene – high strength, resistance to carburisation and the formation of sigma phase
  • Components, e.g. heat exchangers, piping systems etc, in coal conversion plants
  • Steam generator tubing in helium cooled, high temperature reactor systems – high strength, resistance to helium and to steam.