Square Grid

800H/HT®

A nickel-iron-chromium alloy, 800H/HT® is designed for high temperature structural applications

Alloy 800H/HT® is an austenitic heat resistant alloy designed for high temperature structural applications. The strength of 800H/HT® is achieved by controlled levels of carbon, aluminum and titanium along with a 1148°C minimum anneal to achieve a grain size of ASTM 5 or coarser.

Inventory

Product formSize range fromSize range to
800H/HT® round bar12.7 mm203.2 mm
800H/HT® sheet & plate0.6 mm3 mm
800H/HT® pipe0.5 in8 in
800H/HT® flanges0.5 in8 in
800H/HT® pipe fittings0.5 in8 in

Can't find the product you need? Please contact us directly.

Gallery Image

Pipe

Gallery Image

Pipe Fittings

Gallery Image

Flanges

Gallery Image

Sheet & Plate

Gallery Image

Round Bar

Chemical Analysis

%CrNiSiCMnPSCuFeAlAl+Ti
Min19300.0639.50.150.85
Max233510.11.50.0450.0150.750.61.2

Applications

Gallery Image

Perfect for applications in the Petrochemical & Refinery sector

800H/HT® can be used in a variety of applications, here are just a few examples:

  • Super-heaters and re-heater tubing
  • Reformer outlet pigtails and manifolds
  • Heat exchangers
  • Pressure vessels
  • Dampers
  • Industrial furnaces

About 800H/HT®

With close control of the carbon, aluminium and titanium contents combined with the high temperature anneal, 800H/HT® has significantly higher creep-stress rupture strength than Alloy 800.

This alloy is commonly welded using RA82 (ERNiCr-3) bare wire for applications under 788°C. RA330-04 (UNS N08334) bare filler wire offers a closer match than RA82 based on the thermal expansion coefficient and higher strength. For maximum strength alloy 617 (ERNiCrCoMo-1) bare wire or 117 (ENiCrCoMo-1) covered electrodes are suggested.

To avoid possible stress relaxation grain boundary cracking in applications above 538°C the welded fabrication may be heat treated at 899°C for approximately one hour per inch of thickness or 30 minutes minimum followed by air cooling.

 

Properties

Density:
7.94 g/cm³
Melting Range:
1357 – 1385°C
Specific Heat Capacity:
460 J/kg°C (0-100°C)
Curie Temperature:
-115°C

Specifications

UNS Number:
UNS N08810, UNS N08811
Standards:
ASME SB 407 Code Case 1325, ASME SB 408, ASME SB 409, ASTM B 407, ASTM B 408, ASTM B 409
W.Nr:
W. Nr./EN 1.4958, W. Nr./EN 1.4959
Download the 800H/HT® Data Sheet Download

Request a Quote

Fill in our online form to get a fast quote. Got a technical question? Contact us on techsales@neonickel.com or for more general enquiries please email us at enquiries@neonickel.com