1.4958/1.4959 – UNS N08810/N08811 – Alloy 800H/HT

1.4958/1.4959 – UNS N08810/N08811 – Alloy 800H/HT2018-06-18T09:06:54+00:00

1.4958/1.4959

  • N08810/N08811
  • Alloy 800H/HT

Alloys 800H (UNS N08810) and 800HT (UNS N08811) are dual-certifiable Nickel-Iron-Chromium materials that resist oxidation, carburization and other high temperature corrosion. The chemical composition of the two alloys are identical to Alloy 800 (UNS N08800), with the exception of the higher level of carbon present in both grades (0.05 – 0.10%) in alloy 800H, and (0.06 – 0.10%) in alloy 800HT. Alloy 800HT also has an addition of up 1.0 % aluminum and titanium. Application : Chemical and Petrochemical Processing — process equipment for the production of ethylene, ethylene dichloride, acetic anhydride, ketene, nitric acid and oxy-alcohol, power generation, thermal processing fixtures.

Mechanical Properties

Tensile strength:531N/mm²
Yield strength 0,2% :200≥ N/mm²
Elongation:52≥ %
Hardness HB30:127≤ HB

Chemical Composition

Carbon

C

0,5-0,1% max

Silicon

Si

0,75% max

Magnese

Mn

1,50% max

Phosphorus

P

0,045% max

Sulphur

S

0,015% max

Chromium

Cr

19-23% max

Nickel

Ni

30-35% max

Aluminum

Al

see below *1

Titanium

Ti

see below *2

*1  :  0.15 min. – 0.60 max. (800H)    /   0.25 min. – 0.60 max   (800HT)

*2  :  0.15 min. – 0.60 max.(800H)   /   0.25 min. – 0.60 max.(800HT)

Heat Treatment

1149°C mini

The alloys have corrosion resistance that is comparable to 304 when used in nitric and organic acid service. The alloys should not be used in sulfuric acid service. They are subject to chromium carbide precipitation if in service for prolonged exposure in the 1000 – 1400°F(538 – 760°C) temperature range.

Since Alloys 800H and 800AT were developed primarily for high-temperature strength, corrosive environments to which these grades are exposed normally involve high temperature reactions such as oxidationand carburization.

Alloys 800H and 800AT are easily welded and processed by standard

shop fabrication practices.

Marking

All material will be marked as follow:

  • Manufacturer’s name
  • Material grade
  • Size
  • Heat Number

Certification

Material will be delivered with certificate EN 10204 3.1

products

Pipes, piping material

pipes

Flanges, piping material

flanges

Fittings, piping material

fittings

Plates, piping material

plates

Round Bar, piping material

bars

Forged Fittings, piping material

forged fittings