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Material: Incoloy 800, 800H, 800HT, 825
Type: Round bar,Square bar,Hex bar,Flat bar
Tolerance: H7 H9 H10 H11
Surface: Black or Bright or Pickling white
Diameter: 5~500mm
Length: ≦12M or As Per Client's Requirements.
• Grades: Incoloy 800 / 800H / 800HT (high-temperature Ni‑Fe‑Cr) and Incoloy 825 (corrosion-resistant Ni‑Fe‑Cr‑Mo)
• Forms: Round Bar (standard), Flat Bar, Square Bar, Hexagonal Bar; Hot-Rolled, Cold-Drawn, Forged, Centerless Ground
• Key Standards: ASTM B408 (800 series), ASTM B425 (825), ASME equivalents, NACE MR0175
• 800 series: Elevated-temperature service up to 1100°C; creep and rupture strength; resists oxidation, carburization, nitridation
• 825: Broad acid and seawater corrosion resistance; PREN ~31; best choice when 316L fails in reducing acids
Type | Round Bar Square Bar Hexagon Bar Flat Bar | ||
Surface | Black or Bright or Pickling white | ||
Standard | SUS, AISI, DIN | ||
Manufacture Technique | Hot Rolling, Cold-drawing | ||
Diameter | 5~500mm | ||
Length | ≦12M or As Per Client's Requirements. | ||
Diameter Tolerance | H7 H9 H10 H11 | ||
Material Grade | Incoloy 800, 800H, 800HT, 825 | ||
Incoloy round bars divides naturally into two performance families.
The 800 series (Incoloy 800, 800H, and 800HT) is engineered for high-temperature service: furnace tubes, heat-exchanger shells, and radiant tubes in petrochemical steam reformers, where continuous operation above 600°C demands both creep strength and resistance to carburization, nitridation, and oxidation.
The corrosion-resistant family Incoloy 825 brings molybdenum and copper additions that deliver resistance to reducing acids — sulfuric, phosphoric, hydrofluoric — as well as seawater pitting, chloride SCC immunity, and NACE MR0175 compliance in sour oil-and-gas service.
JN Alloys supplies Incoloy round bars and related bar forms in the following standard production size ranges. Custom lengths and cut-to-length services are available on request. All dimensions are in millimetres unless otherwise stated.
Bar Form | Hot-Rolled | Cold-Drawn | Forged |
Round Bar | 10–500 mm Ø | 3–100 mm Ø | 50–800 mm Ø |
Flat Bar | 10–200 × 20–300 mm | 3–50 × 10–100 mm | 50–300 × 100–600 mm |
Square Bar | 10–150 mm | 5–50 mm | 50–300 mm |
Hexagonal Bar | 10–67 mm A/F | 5–50 mm A/F | — |
Wire Rod | — | 0.5–25 mm Ø | — |
Hot-Rolled Incoloy Bars
Billets are heated to 1,150–1,230°C and hot-rolled to final cross-section on roughing and finishing mills. Hot-rolling provides an economical per-kilogram cost and is the standard route for bars ≥ 50 mm diameter. The 800 series is typically annealed at 980–1,150°C (grade-dependent) to dissolve titanium carbides and establish the required grain size; 800HT requires a minimum grain size of ASTM No. 5 for creep-code compliance. Incoloy 825 and 028 are solution annealed at 940–980°C and water-quenched to retain corrosion resistance.
Cold-Drawn / Cold-Finished Incoloy Bars
Cold drawing through precision carbide dies improves dimensional tolerance (h9–h11), surface finish (≤ 1.6 μm Ra), and room-temperature tensile strength through work hardening. Cold-drawn bars are the preferred feedstock for precision machined components — pump shafts, valve stems, instrument fittings, and fasteners — where tight dimensional control reduces machining allowance. For age-hardenable Incoloy 925, cold-drawing is performed on annealed material prior to the aging heat treatment.
Forged Incoloy Bars
Open-die or rotary forging of Incoloy billets refines grain structure and eliminates porosity, yielding superior ultrasonic cleanliness and through-thickness mechanical integrity. Forged bars are mandatory for critical-service components: ASME VIII pressure vessels, API 6A wellhead spool bodies, rotating machinery shafts, and large-diameter valve bodies. All forgings are accompanied by full heat-treatment records and UT examination per ASTM A388 or ASTM E2375.
Grade | UNS | W.Nr. | Base System | Strength Mechanism | Temp. Range | Primary Function |
Incoloy 800 | N08800 | 1.4876 | Ni‑Fe‑Cr | Solid Solution | up to 600°C | High-temp oxidation & carburization resistance |
Incoloy 800H | N08810 | 1.4958 | Ni‑Fe‑Cr | Solid Solution + Creep | 600–900°C | Creep & rupture in reformers, furnaces |
Incoloy 800HT | N08811 | 1.4959 | Ni‑Fe‑Cr | Solid Solution + Creep | 900–1000°C | Best creep resistance of 800 series; ASME coded |
Incoloy 825 | N08825 | 2.4858 | Ni‑Fe‑Cr‑Mo‑Cu | Solid Solution | up to 450°C | Broad acid & seawater corrosion resistance |
Source: Special Metals Corporation Technical Bulletins; ASTM B408, B425, B805, B649. Incoloy® is a registered trademark of Special Metals Corporation.
All Incoloy round bars from JN Alloys are manufactured, tested, and certified to the relevant international standard(s) listed below. Material Test Certificates are issued to EN 10204 Type 3.1 (or 3.2 on request), covering chemical composition, mechanical properties, heat-treatment condition, and dimensional inspection.
Code | Standard Title | Alloys Covered | Scope |
ASTM B408 | Ni‑Fe‑Cr Alloy Rod and Bar | N08800 / N08810 / N08811 | Chemistry, tensile, hardness, dimensions (hot-worked & cold-worked) |
ASME SB408 | Ni‑Fe‑Cr Alloy Rod and Bar (BPVC) | Same as B408 | Pressure vessel / boiler code equivalent of ASTM B408 |
ASTM B425 | Ni‑Fe‑Cr‑Mo‑Cu Alloy Rod and Bar | N08825 | Chemistry, tensile, hardness; annealed condition only |
ASME SB425 | Ni‑Fe‑Cr‑Mo‑Cu Alloy Rod and Bar (BPVC) | N08825 | BPVC Section VIII code equivalent of ASTM B425 |
NACE MR0175 | Sulfide Stress Cracking Resistant Materials | Incoloy 825 | Sour service (H₂S) in oil & gas production; hardness limits for 925 |
ISO 15156‑3 | Mat. for H₂S in Oil & Gas Production – Part 3 | Incoloy 825 | International equivalent of NACE MR0175 for CRAs |
EN 10269 | Steels and Ni Alloys for Fasteners at Elevated Temp. | N08800, N08810, N08825 | European standard covering bar for high-temp bolting |
DIN 17459 | Seamless Tubes / Bars of Ni-Fe-Cr Alloys | W.Nr. 1.4876, 1.4958, 1.4959, 2.4858 | German/European dimensional and property standard |
Source: ASTM International, ASME Boiler and Pressure Vessel Code, API, NACE International, DIN/EN.
800 Series (High-Temperature Ni‑Fe‑Cr)
Grade | Ni+Co | Fe | Cr | Al | Ti | C max | Al+Ti (total) | C (controlled range) |
Incoloy 800 | 30.0–35.0 | Balance | 19.0–23.0 | 0.15–0.60 | 0.15–0.60 | 0.10 | 0.30–1.20 | ≤ 0.10 |
Incoloy 800H | 30.0–35.0 | Balance | 19.0–23.0 | 0.15–0.60 | 0.15–0.60 | 0.10 | 0.30–1.20 | 0.05–0.10 |
Incoloy 800HT | 30.0–35.0 | Balance | 19.0–23.0 | 0.25–0.60 | 0.25–0.60 | 0.10 | 0.85–1.20 | 0.06–0.10 |
Source: ASTM B408. Mn ≤ 1.5%, Si ≤ 1.0%, S ≤ 0.015%, Cu ≤ 0.75% for all three grades. All values in weight percent.
Corrosion-Resistant Series (Ni‑Fe‑Cr‑Mo‑Cu)
Grade | Ni | Fe | Cr | Mo | Cu | Ti | Al | C max | Other |
Incoloy 825 | 38.0–46.0 | Balance | 19.5–23.5 | 2.5–3.5 | 1.5–3.0 | 0.6–1.2 | ≤ 0.20 | 0.05 | Mn ≤ 1.0, Si ≤ 0.5, S ≤ 0.03 |
Source: ASTM B425 (Incoloy 825); ASTM B805 (Incoloy 925); ASTM B649 (Incoloy 028). All values in weight percent.
Grade / Condition | Tensile (MPa) | Yield 0.2% (MPa) | Elong. (%) | Hardness | Density (g/cm³) | Melting Range (°C) |
Incoloy 800 — Annealed | ≥ 520 (75 ksi) | ≥ 205 (30 ksi) | ≥ 30 | ≤ 197 HB | 7.94 | 1,357–1,385 |
Incoloy 800H — Annealed | ≥ 520 (75 ksi) | ≥ 205 (30 ksi) | ≥ 30 | ≤ 197 HB | 7.94 | 1,357–1,385 |
Incoloy 800HT — Annealed | ≥ 520 (75 ksi) | ≥ 205 (30 ksi) | ≥ 30 | ≤ 197 HB | 7.94 | 1,357–1,385 |
Incoloy 825 — Annealed | ≥ 690 (100 ksi) | ≥ 310 (45 ksi) | ≥ 30 | ≤ 200 HB | 8.14 | 1,370–1,400 |
Source: ASTM B408 (800 series), ASTM B425 (825), ASTM B805 (925), ASTM B649 (028); Special Metals Corporation Technical Bulletins. Values are minimum unless stated as typical.
The defining competitive advantage of Incoloy 800H and 800HT over conventional austenitic stainless steels is their superior creep and stress-rupture strength above 650°C.
Alloy | 100-hr Rupture Stress at 800°C | 100-hr Rupture Stress at 900°C | Max. Continuous Service Temp. | Resistance to Carburization | Resistance to Nitridation |
Incoloy 800 | ~83 MPa | ~41 MPa | 900°C | Good | Good |
Incoloy 800H | ~97 MPa | ~48 MPa | 980°C | Good | Good |
Incoloy 800HT | ~110 MPa | ~55 MPa | 1,000°C | Excellent | Excellent |
SS 304H | ~48 MPa | ~20 MPa | 870°C | Moderate | Moderate |
SS 310S | ~55 MPa | ~27 MPa | 1,050°C | Good | Good |
Source: Special Metals Corporation Incoloy Alloy 800H/800HT Technical Bulletin; ASM Handbook Vol. 4E (Heat Treating of Nonferrous Alloys). Rupture stress values are approximate mid-range from published data.
Q: What is the difference between Incoloy 800, 800H, and 800HT?
All three are the same base alloy (Ni–32%, Cr–21%, Fe balance), but they differ in carbon content and grain size requirements, which control creep performance at elevated temperatures. Incoloy 800 has no carbon or grain size restriction and is used up to about 600°C. Incoloy 800H requires C: 0.05–0.10% and a minimum grain size of ASTM No. 5 to maximize creep strength at 600–900°C. Incoloy 800HT adds a tighter Al+Ti window (0.85–1.20% combined) to further stabilize the gamma-prime precipitate, providing the best creep/rupture resistance above 900°C; it is ASME Section VIII Div. 1 coded for continuous service up to 1000°C.
Q: When should I choose Incoloy 825 instead of 316L stainless steel?
Incoloy 825 outperforms 316L in three specific scenarios: (1) reducing-acid environments such as dilute sulfuric acid (< 70%) or phosphoric acid where 316L’s corrosion rate is unacceptably high; (2) environments where chloride stress-corrosion cracking (Cl⁻ SCC) is a risk — Incoloy 825’s 38–46% Ni content makes it immune, whereas 316L fails by SCC above ~60°C in chloride service; (3) seawater pitting environments where Incoloy 825’s PREN of ~31 far exceeds 316L’s ~24. 316L remains cost-competitive in mild conditions; use 825 when the corrosion engineer identifies the risk of SCC, pitting, or acid attack.
Q: What makes Incoloy 925 suitable for downhole sour gas service?
Incoloy 925 is an age-hardenable alloy (UNS N09925) that achieves both high strength (tensile ≥ 1000 MPa, yield ≥ 827 MPa in the aged condition) and full NACE MR0175 / ISO 15156-3 compliance in sour oil & gas environments. Most high-strength steels and 13% Cr martensitic stainless steels suffer sulfide stress cracking (SSC) at comparable strength levels. Incoloy 925 is immune to SSC because its Ni–45% matrix resists hydrogen embrittlement at the NACE-permitted hardness limit of ≤ 35 HRC. It is specified in API 6A PSL-3 and PSL-4 wellhead components, downhole tool mandrels, and safety valves.
Q: Can Incoloy bars be welded?
Yes. All Incoloy grades are weldable by GTAW (TIG), GMAW (MIG), and SMAW processes. Recommended filler metals: ERNiCr-3 / ENiCrFe-3 (AWS A5.14/A5.11) for the 800 series; ERNiCrMo-3 (Inconel 625 filler) for Incoloy 825 and 028; ERNiCrMo-3 or ERNiCrMo-4 for Incoloy 925. No preheating is required for the 800 series. For Incoloy 925 in the aged condition, weld in the annealed condition and perform post-weld aging. Interpass temperature should not exceed 150°C to minimize carbide sensitization in the heat-affected zone.
Q: What is the maximum service temperature for Incoloy bars?
The answer depends on the grade and failure mode being controlled. For oxidation resistance only, Incoloy 800HT can operate continuously to 1,100°C. For load-bearing service (creep/rupture), the ASME maximum design temperature is approximately 1,000°C for 800HT in ASME Section VIII. For the corrosion-resistant grades (825, 925, 028), the upper limit is set by microstructural sensitization (typically 450°C for 825 and 028; 260°C for aged 925 in sour service). Above these temperatures, corrosion resistance can be impaired by carbide precipitation.
Q: What is the lead time for Incoloy round bars?
Standard stock sizes of Incoloy 825 (10–100 mm hot-rolled) and Incoloy 800 (20–150 mm) are available ex-stock with 3–7 day dispatch. Non-stock sizes and Incoloy 800H/800HT, 925, and 028 require mill production of 4–8 weeks for standard shapes. Forged bars above 200 mm diameter and NACE-certified Incoloy 925 typically require 8–12 weeks including testing and certification. Contact our technical sales team for expedited mill scheduling on urgent projects.
Q: How does Incoloy 028 differ from Incoloy 825 in acid service?
Both alloys resist a broad range of acids, but their compositions are tuned for different acid environments. Incoloy 825 (Cr ~21%, Mo ~3%, Cu ~2%) is optimized for dilute sulfuric acid, hydrofluoric acid, and seawater. Incoloy 028 (Cr ~27%, Mo ~3.5%, Cu ~1%) has significantly higher chromium, which provides superior resistance to both oxidizing and reducing forms of sulfuric acid across the full concentration range (0–98%), and exceptional resistance to wet-process phosphoric acid containing chlorides and fluorides — an environment that degrades 825 significantly. Incoloy 028 is the preferred choice for fertilizer production, FGD systems, and phosphoric acid plants; Incoloy 825 is preferred for seawater, HF acid, and mixed acid-chloride service.
Q: Are Incoloy round bars magnetic?
The 800 series (N08800, N08810, N08811) and Incoloy 825 (N08825) are austenitic alloys and are essentially non-magnetic. Incoloy 925 in the annealed condition is non-magnetic; after aging, a slight increase in permeability may occur. Incoloy 028 is fully austenitic and non-magnetic. If strict non-magnetic properties are required for a specific application (e.g., MRI components, magnetic separation equipment), consult our technical team for measured permeability values on specific heats.
