Incoloy 800H (UNS N08810 ASTM B154) Seamless Pipe
Incoloy 800 and 800H are nickel-iron-chromium alloys with good
strength and excellent resistance to oxidation and carburization in
high-temperature exposure. These nickel steel alloys are identical
except for the higher level of carbon in alloy 800H, and the
addition of up to 1.20 percent aluminum and titanium in alloy
800HT. Incoloy 800 was the first of these alloys and it was
slightly modified into Incoloy 800H. This modification was to
control carbon (.05-.10%) and grain size to optimize stress rupture
properties. Incoloy 800HT has further modifications to the combined
titanium and aluminum levels (.85-1.20%) to ensure optimum high
temperature properties.The nickel alloy is dual certified (800H/HT) and combines the
properties of both forms. Incoloy 800H/HT alloy was intended for high temperature structural
applications. The nickel content makes the alloys highly resistant
to both chloride stress-corrosion cracking and to embrittlement
from precipitation of sigma phase. The general corrosion resistance
is excellent. In the solution annealed condition, alloys 800H and
800HT have superior creep and stress rupture properties. Today,
most suppliers, including Mega Mex, only carry the dual certified
800H/HT alloy.
Incoloy 800 is primarily used in applications with temperatures up
to 1100° F, where alloys 800H and 800HT are normally used in
temperatures above 1100° F where resistance to creep and rupture is required. The
chemical balance allows the nickel steel alloy to exhibit excellent
resistance to carburization, oxidation and nitriding atmospheres.
Incoloy 800HT will not become embrittled even after long periods of
usage in the 1200-1600° F range where many stainless steels become
brittle. Excellent cold forming characteristics typically
associated with the nickel-chromium alloys are exhibited with
800HT. When cold formed extensively the grain size produces a
visibly undulated surface called “orange peel”. Incoloy 800HT can
be welded by the common techniques used on stainless steels.
In what forms is Incoloy 800H/HT available at Huaan Steel?
- Sheet
- Plate
- Bar
- Pipe & Tube (welded & seamless)
- Fittings (i.e. flanges, slip-ons, blinds, weld-necks, lapjoints,
long welding necks, socket welds, elbows, tees, stub-ends, returns,
caps, crosses, reducers, and pipe nipples)
- Wire
What are the characteristics of Incoloy 800H/HT?
- High temperature strength
- High creep rupture strength
- Resistant to oxidation and carburization in high temperature
environments
- Good corrosion resistance in many acidic environments
- Good resistance to many sulfur-containing atmospheres
Alloy 800 (UNS N08800) Chemical Composition, %
| Ni | Fe | Cr | Cu | Ti | Al | C | Mn | S | Si |
|---|
| 30.0-35.0 | 39.5 min | 19.0-23.0 | .75 max | .15-.60 | .15-.60 | .1 max | 1.5 max | .015 max | 1.0 max |
Alloy 800H (UNS N08810) Chemical Composition, %
| Ni | Fe | Cr | Cu | Ti | Al | C | Mn | S | Si |
|---|
| 30.0-35.0 | 39.5 min | 19.0-23.0 | .75 max | .15-.60 | .15-.60 | .05-.10 max | 1.5 max | .015 max | 1.0 max |
In what applications is Incoloy 800H/HT used?
· Ethylene furnace quench boilers
· Hydrocarbon cracking
· Valves, fittings and other components exposed to corrosive attack
from 1100-1800° F
· Industrial furnaces
· Heat-treating equipment
· Chemical and petrochemical processing
· Super-heater and re-heaters in power plants
· Pressure vessels
· Heat exchangers
Alloys 800H/HT are used in a variety of applications involving
exposure to corrosive environments and high temperatures such as
heat treating equipment, chemical and petrochemical processing,
nuclear power plants and the paper pulp industry. Heat-treating
equipment such as baskets, trays, and fixtures employ Incoloy
800H/HT. Chemical and petrochemical processing industries use the
alloys for heat exchangers and other piping systems in nitric acid
media especially where resistance to chloride stress-corrosion
cracking is required. Power plants use them for super-heater and
re-heater tubing.
