Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Incoloy 800H FAQ
This consolidated FAQ hub answers the most common questions about Incoloy 800H (UNS N08810, Werkstoff 1.4876) and Incoloy 800HT (UNS N08811) across chemistry, mechanical properties, design stress, heat treatment, welding, fabrication, certification and application selection. Each answer below is also surfaced on the relevant product or reference page; this hub gives a single landing point for procurement engineers, project metallurgists, inspection authorities and fabrication QA reviewers who need a fast lookup across multiple topics. For deeper treatment of any single topic, follow the embedded link to the dedicated reference page. This page carries noindex,follow so it does not compete with the topic pages for search-engine attention, but it does pass link-equity through the embedded internal anchors and surfaces in Google's People Also Ask blocks for the consolidated FAQ schema.
Grade Distinction (800 vs 800H vs 800HT)
Q. What is the difference between Incoloy 800, 800H and 800HT?
Standard Incoloy 800 (UNS N08800) is the baseline alloy for general heat resistance below 650 deg C. Incoloy 800H (UNS N08810) carries controlled carbon 0.05 to 0.10 percent and ASTM grain size 5 or coarser to qualify for sustained service to 815 deg C under ASME Section VIII. Incoloy 800HT (UNS N08811) adds Al+Ti window 0.85 to 1.20 percent to extend creep-rupture strength to 982 deg C. See full comparison.
Q. Is Incoloy the same as Inconel?
No. Incoloy is a nickel-iron-chromium family with iron-base matrix (30 to 35 percent Ni). Inconel is a nickel-chromium family with nickel-base matrix (above 50 percent Ni). Different alloy classes, different specifications, different price levels. See Incoloy vs Inconel disambiguation.
Standards + ASME Code
Q. Is Incoloy 800H ASME-code qualified?
Yes. 800H is listed in ASME Section II Part B as SB-407 (seamless pipe and tube), SB-408 (rod and bar), SB-409 (plate, sheet, strip) and SB-564 (forgings) with maximum design temperature 815 deg C for Section VIII Division 1 service. See ASME Section VIII and design stress tables.
Q. What ASTM specifications cover Incoloy 800H?
ASTM B407 (seamless pipe and tube), ASTM B408 (rod and bar), ASTM B409 (plate, sheet, strip), ASTM B514 (welded pipe), ASTM B515 (welded tube), ASTM B564 (forgings) and ASTM A608 (centrifugally cast tubes - for the 800H-envelope chemistry).
Q. What is the maximum service temperature for 800H?
815 deg C (1500 deg F) for ASME Section VIII pressure-vessel design. For sustained service above 815 deg C, the 800HT (UNS N08811) grade extends design qualification to 982 deg C (1800 deg F). Useful oxidation resistance is retained to 982 deg C in both grades.
Chemistry and Mechanical Properties
Q. What is the chemistry envelope for 800H?
30 to 35 Ni, 19 to 23 Cr, balance Fe, 0.05 to 0.10 C, combined Al+Ti 0.30 to 1.20 percent (800H) or 0.85 to 1.20 percent (800HT). See chemical composition.
Q. What is the room-temperature yield and UTS for 800H?
Yield 170 MPa minimum (25 ksi), UTS 450 MPa minimum (65 ksi), elongation 30 percent minimum in 4D, hardness Rockwell B 70 to 90 in solution-annealed condition. See mechanical properties.
Q. How does 800H high-temperature yield compare to room-temperature?
At 540 deg C the yield drops to approximately 70 percent of room-temperature value; at 650 deg C to approximately 55 percent; at 815 deg C to approximately 35 percent. See high-temperature strength.
Heat Treatment
Q. What is the standard heat treatment for 800H?
Solution anneal at 2050 deg F (1121 deg C) for 1 hour per 25 mm of section, followed by accelerated air cool (water quench on heavy sections). This is mandatory under ASTM B407 / B408 / B409 / B564 acceptance.
Q. Is post-weld heat treatment required for 800H?
Not for routine ASME Section VIII pressure-vessel service. A full re-solution anneal at 2050 deg F is supplied on call-out for fabrications requiring maximum long-term creep performance. See weldability procedures.
Welding
Q. What filler metal do I use for welding 800H?
ERNiCrFe-2 (AWS A5.14) is the standard for GTAW / GMAW / SAW. ENiCrFe-2 or ENiCrFe-3 (AWS A5.11) for SMAW. ERNiCrFe-7 for reducing or carburising service. See weldability procedures.
Q. Do I need to preheat 800H?
No. Preheat is not required. Welding at ambient (above 15 deg C) is the standard. Interpass temperature held below 175 deg C (350 deg F) to limit HAZ grain coarsening.
Applications
Q. What are the canonical applications for 800H?
Ethylene cracker furnace tubes, hydrogen reformer pigtails, fired-heater radiant-section coils, steam superheater tubes, shell-and-tube heat exchangers, ASME Section VIII pressure vessels. See ethylene cracker tubes, reformer pigtails, steam superheaters.
Q. Is 800H suitable for carburising service?
Yes. The 30 to 35 percent Ni base and the controlled Al+Ti chemistry deliver good carburisation resistance, qualifying 800H for ethylene cracker furnace tubes where carbon ingress from cracked hydrocarbons is the principal degradation mechanism. See carburization resistance.
Certification and Procurement
Q. Do you supply 800H with EN 10204 type 3.2 certification?
Yes. Type 3.1 is supplied by default. Type 3.2 with Lloyds Register, DNV, BV, SGS or TUV third-party witness is supplied on call-out for refinery, LNG, ASME Section VIII pressure-vessel and subsea procurement.
Q. Do you supply 800H to PED 2014/68/EU?
Yes. TorqBolt is PED 2014/68/EU certified. The Annex I conformity-assessment certificate signed by a Notified Body is supplied in addition to the EN 10204 type 3.1 or 3.2 material certificate.
Q. Do you supply 800H to NACE MR0175 sour-service?
Yes. 800H in solution-annealed condition meets the NACE MR0175 / ISO 15156 hardness limit of 22 HRC (237 HV) for Ni-Fe-Cr alloys. The NACE MR0175 compliance statement is added to the EN 10204 certificate.
Product Forms Available
Q. What product forms does TorqBolt supply in 800H?
Full range: forgings (TorqBolt-manufactured), flanges (TorqBolt-manufactured), fittings (TorqBolt-manufactured), machined components (TorqBolt-manufactured), seamless pipe, welded pipe, seamless tube, centrifugally cast tubes, plate, sheet, round bar, fasteners.
Q. What is the maximum size envelope?
Forgings to 1500 kg single piece, plate to 100 mm thick x 2500 mm wide, seamless pipe to NPS 12 inch, welded pipe to NPS 24 inch, round bar to OD 250 mm. Larger sizes available on call-out.
Where to Send a Project RFQ
Send project RFQs with line-list, NPS / OD / wall / thickness, ASTM specification, EN 10204 certification class, NACE / PED / project add-ons to our sales desk. For technical-only queries (data sheet, design-stress lookup, welding-procedure guidance, application selection), the sales desk routes the query to the QA-QC manager and we respond with the relevant reference data.
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