Overview

Incoloy alloy bars are solid, long metal products manufactured from a family of austenitic nickel-iron-chromium superalloys, representing one of the most versatile and cost-effective material solutions for moderate-to-high temperature applications and corrosive environments. These bars are produced through hot rolling, forging, extrusion, or cold drawing processes, resulting in round, square, flat, or hexagonal cross-sections that serve as the foundation for countless industrial components across chemical processing, oil and gas, power generation, and heat-treating industries .

Incoloy alloys are characterized by their nickel content typically ranging from 30-46% combined with chromium (19-23%) and significant iron content (typically >22%) , creating a unique balance of properties that bridges the performance gap between stainless steels and more expensive nickel-based superalloys . Unlike Inconel alloys which prioritize extreme high-temperature performance, Incoloy alloys offer an economical solution for applications where stainless steel performance is inadequate but premium nickel alloys would be over-specified .

The alloy family encompasses several distinct grades optimized for specific service conditions—from the high-temperature creep resistance of Incoloy 800H/HT for furnace components, through the exceptional acid resistance of Incoloy 825 for chemical processing, to the age-hardenable high-strength grades like Incoloy 925 and 945 for demanding oil and gas applications . This versatility, combined with good fabricability and cost-effectiveness, makes Incoloy alloy bars the preferred choice for engineers seeking reliable performance without unnecessary premium material costs .

With diameters typically ranging from 2mm to 600mm and lengths customized to requirements, Incoloy alloy bars transform the unique properties of nickel-iron-chromium alloys into versatile engineering stock for manufacturing valve components, pump shafts, fasteners, fittings, heat exchanger parts, and precision-machined components for critical service environments .

Key Features

• Cost-Effective Performance Bridge: Incoloy alloys occupy the strategic middle ground between stainless steels and high-nickel superalloys. With nickel content of 30-46%, they offer significantly better performance than 300-series stainless steels in high-temperature and corrosive environments, while providing substantial cost savings compared to Inconel or Hastelloy grades .

• Multiple Strengthening Mechanisms Available: Incoloy alloy bars are available with different strengthening approaches to match application needs:

  • Solid-solution strengthened (800, 800H/HT, 825): Good fabricability, weldable without post-weld heat treatment

  • Precipitation-hardenable (A-286, 925, 945): Maximum strength through aging heat treatment, with yield strengths from 125 ksi to over 170 ksi depending on grade and condition

• Exceptional High-Temperature Performance: Grades like Incoloy 800H and 800HT are specifically engineered for elevated temperature service, with controlled carbon content and grain size providing superior creep and rupture strength up to 1100°C (2000°F) . These alloys maintain structural integrity under extreme thermal cycling, making them ideal for furnace components and heat-treating equipment .

• Superior Corrosion Resistance in Diverse Media: Incoloy alloys offer outstanding resistance to a wide range of corrosive environments:

  • Incoloy 825: Exceptional resistance to sulfuric, phosphoric, and nitric acids, with molybdenum and copper additions targeting reducing acid environments

  • Incoloy 945/945X: Superior resistance to stress corrosion cracking in hydrogen sulfide-rich environments, with NACE MR0175/ISO 15156 certification for sour gas service

  • All grades: High nickel content provides immunity to chloride-induced stress corrosion cracking

• Excellent Fabricability: Incoloy alloys are generally more fabricable than higher-nickel alternatives due to their balanced composition. They can be successfully machined, welded, and formed using conventional techniques with proper procedures . Grades like 825 offer good machinability, while age-hardenable grades may require solution-annealed condition for extensive machining prior to aging .

• NACE/API Compliance for Oil & Gas: Premium grades such as Incoloy 945, 945X, and 925 are available with full NACE MR0175/ISO 15156 certification for sour service applications . Incoloy 945 is approved for Level VII and Level VI-450°F environments, making it suitable for the most demanding H₂S-containing conditions .

• Wide Range of Available Forms: Incoloy alloy bars are offered in multiple shapes to suit diverse applications:

  • Round bars: The most common form for shafts, valves, fasteners, and general machining (2mm to 600mm diameter)

  • Flat bars: Ideal for structural supports, flanges, and custom fabrications

  • Square and hexagonal bars: Preferred for fasteners, fittings, and tool stock

  • Hollow bars: Tubular forms that reduce machining costs for components like flanges and valves

  • Forging stock: Larger sections intended for subsequent hot working into complex shapes

Specifications with Explanation

Incoloy Alloy Bar Chemical Composition by Grade (Typical values, wt%)

Typical Mechanical Properties

Physical Properties

Applicable Bar Standards

Available Bar Dimensions and Forms

Surface Finishes Available

• Hot rolled pickled

• Cold drawn (bright)

• Centerless ground

• Turned and polished

• Black / as-rolled (for forging stock)

• Rough turned

• No.4 finish, Matt finish, BA finish

• Sand blasted finish

Tolerance Grades Available

• H8, H9, H10, H11, H12, H13

• K9, K10, K11, K12

• Custom tolerances per client requirements

Applications

Incoloy alloy bars serve as the essential raw material for countless precision components across industries where moderate-to-high temperature performance and corrosion resistance are required without the premium cost of higher-nickel alloys:

Chemical Processing Industry

• Heat Exchanger Components: Tube sheets, baffles, and tie rods for corrosive service, particularly with Incoloy 825 handling sulfuric and phosphoric acids

• Reactor Internals: Agitator shafts and support grids for chemical reactors

• Valve Components: Stems, seats, balls, and bodies for valves handling corrosive chemicals at elevated temperatures

• Pump Shafts and Impellers: Rotating components in pumps transferring acids and aggressive process fluids

• Pickling Equipment: Components for steel pickling operations using sulfuric and hydrochloric acids

Oil and Gas Industry

• Sour Gas Service Components: Subsurface safety valves, tubing hangers, landing nipples, packers, and drill tools in H₂S environments using Incoloy 945/945X

• Wellhead Equipment: Valves for sour service, high-pressure pumps, and completion equipment

• Downhole Tools: High-strength components requiring NACE MR0175/ISO 15156 compliance

• OCTG (Oil Country Tubular Goods): Premium threaded connections and tubular components

• Subsea Equipment: Critical connectors and fasteners for deepwater operations

Industrial Heating and Heat Treating

• Furnace Components: Radiant tubes, muffles, retorts, and conveyor systems operating up to 1100°C with Incoloy 800H/HT

• Heat-Treating Baskets and Fixtures: For carburizing and nitriding atmospheres requiring oxidation resistance

• Annealing Covers: For batch annealing operations in steel processing

• Salt Pots: Containers for molten salt heat treatment

Power Generation

• Steam Superheater Tubing: Components for power plant boilers

• Gas Turbine Components: Frames, casings, and support structures

• Nuclear Reactor Components: Control rod mechanisms and fuel element hardware

Aerospace and Defense

• Turbine Components: Turbine wheels, blades, frames, and casings using A-286

• Jet Engine Parts: Afterburner components, fasteners, and support structures

• Fasteners: High-strength bolts and studs for elevated temperature service

• Springs: High-temperature springs for aerospace applications

Automotive Industry

• Engine Components: Turbocharger parts, exhaust manifold components, and valve train hardware

• Emission Control Systems: Components requiring thermal stability and corrosion resistance

Pollution Control

• Flue Gas Desulfurization (FGD) Systems: Components requiring resistance to sulfuric acid condensate

• Waste Incineration Equipment: Parts exposed to high-temperature corrosive flue gases

Marine Engineering

• Seawater Handling Systems: Piping and components requiring chloride stress corrosion cracking resistance

• Desalination Plants: Heat exchanger components for multi-stage flash evaporators

Comparison: Grade Selection Guide

Buying Guide

Selecting the appropriate Incoloy alloy bar requires careful evaluation of service conditions, mechanical requirements, fabrication considerations, and economic factors:

1. Define Service Environment:

   • Temperature Range: Maximum operating temperature and thermal cycling conditions

     • Up to 500-600°C: All grades suitable

     • 600-815°C: 800H/HT optimal for creep resistance

     • 815-1100°C: 800H/HT, 330 for oxidation resistance

     • Above 1100°C: Consider Inconel or other high-temperature alloys

   • Corrosive Media: Identify specific chemicals, concentrations, and whether oxidizing or reducing conditions prevail

     • Reducing acids (H₂SO₄, H₃PO₄): Incoloy 825 with Mo and Cu additions

     • Sour gas (H₂S): 925, 945, 945X with NACE certification

     • High-temperature oxidation: 800H/HT, 330

   • Mechanical Loading: Static, cyclic, or impact loading; rotating applications require fatigue resistance

2. Select Strengthening Mechanism:

   • Solid-solution strengthened (800, 800H/HT, 825, 330): Good fabricability, weldable without post-weld heat treatment

   • Precipitation-hardenable (A-286, 925, 945, 945X): Maximum strength through aging heat treatment

3. Verify NACE/API Requirements for Oil & Gas:

   • For sour service (H₂S environments), specify NACE MR0175/ISO 15156 compliance

   • Incoloy 945 offers Level VII (all environments) and Level VI-450°F certification

   • Incoloy 945X offers Level VII and Level VI at 450°F to max hardness of 42 HRC

   • A-286 also available with NACE MR0175 compliance

4. Determine Bar Form and Dimensions:

   • Round Bar: For shafts, valves, general machining (5mm to 500mm diameter common)

   • Flat Bar: For structural supports, flanges, custom fabrications

   • Hex/Square Bar: For fasteners, fittings, tool stock

   • Hollow Bar: For components requiring through-holes—reduces machining costs

   • Specify diameter/size, length, and tolerance requirements (H8-H13, K9-K12 available)

5. Specify Condition and Finish:

   • Annealed: Softest, most machinable, suitable for extensive machining

   • Solution treated: For age-hardenable grades prior to aging

   • Age-hardened: For precipitation-hardened condition with maximum strength

   • Cold drawn: Tighter tolerances, improved surface finish

   • Centerless ground: Precision surface for critical applications

   • Surface finish: Bright, polished, black, rough turned, pickled as required

6. Verify Specifications and Standards:

   • Confirm applicable ASTM/ASME standards:

     • 800: ASTM B408 / ASME SB-408

     • 825: ASTM B425 / ASME SB-425

     • A-286: ASTM A638

     • 925/945: ASTM B805, B983

     • 330: ASTM B511

   • For aerospace applications, verify AMS specifications

   • For pressure applications, ensure ASME code compliance

7. Consider Fabrication Requirements:

   • Machining: Incoloy alloys work-harden; use rigid setups, sharp tools, and consistent feed rates

   • Welding: Most grades offer good weldability with matching filler metals; age-hardenable grades typically welded in solution-annealed condition

   • Heat Treatment: For age-hardenable grades, follow recommended solution annealing and aging cycles

8. Request Documentation:

   • Mill Test Certificates (MTC) per EN 10204 3.1/3.2 with:

     • Heat number and full chemical composition

     • Complete mechanical property test results

     • Heat treatment records

   • NACE/ISO certification for sour service grades

   • Third-party inspection reports for critical applications

FAQ

Q1: What is the difference between Incoloy 800, 800H, and 800HT bars?

A: The primary differences lie in carbon content and grain size control, which affect high-temperature properties. Incoloy 800 is the basic grade with general-purpose high-temperature capabilities. Incoloy 800H has controlled carbon (0.05-0.10%) and larger grain size to provide superior creep and rupture strength at temperatures above 815°C . Incoloy 800HT has additional controls on aluminum and titanium (Al+Ti 0.85-1.20%) with similar carbon range, offering the highest creep resistance of the three . All three share similar corrosion resistance, but 800H and 800HT are preferred for applications requiring long-term structural stability under stress at elevated temperatures.

Q2: What is the difference between Incoloy and Inconel bars?

A: The primary difference is nickel content and base composition. Incoloy alloys are nickel-iron-chromium based with nickel content typically 30-46% , making them more economical for moderate-temperature service where stainless steel performance is inadequate but Inconel would be over-specified. Inconel alloys are nickel-chromium based with nickel content typically above 50% (often 58-72%), offering superior high-temperature strength and oxidation resistance above 980°C. Incoloy provides excellent performance in the 540-980°C range with better economy, while Inconel is preferred for extreme high-temperature applications above 980°C.

Q3: What NACE standards apply to Incoloy bars for oil and gas?

A: For oil and gas sour service (environments containing hydrogen sulfide), several Incoloy grades comply with NACE MR0175/ISO 15156. This standard defines material requirements for resistance to sulfide stress cracking (SSC) and stress corrosion cracking (SCC) in H₂S-containing environments:

• Incoloy 945: Certified for Level VII (all environments) and Level VI-450°F

• Incoloy 945X: Certified for Level VII and Level VI at 450°F to max hardness of 42 HRC

• Incoloy A-286: Available with NACE MR0175 compliance for appropriate applications

• Incoloy 925: Widely used in NACE-compliant applications, meeting requirements with proper heat treatment

Q4: Can Incoloy 825 bars replace stainless steel in acid service?

A: Yes, and this is often the logical upgrade path. Where 316L stainless steel fails in sulfuric or phosphoric acid environments due to general corrosion or pitting, Incoloy 825 typically provides 5-10x longer service life. It is particularly effective in the 10-40% sulfuric acid concentration range at moderate temperatures. The molybdenum and copper additions provide targeted resistance to reducing acids, while the high nickel content (>40%) provides immunity to chloride stress corrosion cracking .

Q5: What is the maximum service temperature for Incoloy 800H/HT bars?

A: Incoloy 800H and 800HT maintain useful mechanical properties for continuous service up to approximately 1100°C (2000°F) , with excellent oxidation resistance throughout this range . For applications requiring creep resistance, they perform well up to 815°C (1500°F). Above these temperatures, oxidation resistance remains good, but mechanical strength may gradually decrease. For higher temperature requirements, consider Inconel 600 or 625.

Delivery, Certification & Service

Quality Certification

• Material Traceability: Complete heat traceability from melt to finished bar with unique identification markings per applicable standards

• Mill Test Certificates (MTC) : EN 10204 3.1/3.2 compliant certificates provided with every shipment including:

  • Heat number and full chemical composition analysis per applicable specifications

  • Complete mechanical property test results (tensile, yield, elongation, reduction of area)

  • Hardness testing where applicable

  • Heat treatment records (solution annealing and aging cycles)

  • Ultrasonic inspection reports when specified

• Third-Party Inspection: Available through Lloyds, DNV, Bureau Veritas, ABS, SGS, TÜV, or customer-nominated agencies

• Special Testing Available:

  • Positive Material Identification (PMI)

  • Ultrasonic inspection (Flaw detection)

  • Mechanical testing at elevated or cryogenic temperatures

  • Microstructural evaluation (grain size, precipitate distribution)

  • NACE MR0175/ISO 15156 compliance verification for sour service

  • Intergranular corrosion testing

  • Hardness mapping for large sections

Available Bar Forms and Dimensions

Surface Finishes Available

• Hot Rolled Pickled: Standard industrial finish

• Cold Drawn (Bright) : Improved dimensional tolerances, smooth finish

• Centerless Ground: Precision diameter control, excellent surface finish

• Turned and Polished: For large diameter bars requiring smooth surface

• Rough Turned: For large sections, removes surface imperfections

• No.4 Finish: Polished finish for aesthetic requirements

• Matt Finish: Uniform matte appearance

• BA Finish: Bright annealed finish

• Sand Blasted: Textured finish for specific applications

• Black / As-Rolled: For forging stock or further processing

Tolerance Grades Available

• H Series: H8, H9, H10, H11, H12, H13 (increasing tolerance range)

• K Series: K9, K10, K11, K12

• Custom tolerances per client drawings and specifications

• Precision tolerances for critical applications

Packaging and Protection

• Bundling: Steel-strapped bundles with protective spacers for straight lengths

• Wooden Crates: Export-grade wooden boxes for high-value or precision bars

• Individual Wrapping: Protective paper or plastic for polished/ground surfaces

• VCI Protection: Vapor Corrosion Inhibitor materials for long-term storage or marine shipment

• End Protection: Plastic caps for precision bars to prevent end damage

• Custom Marking: Stenciling, tagging, or stamping per customer specifications

• Export Packing: seaworthy wooden cases with waterproof lining

After-Sales Technical Support

• Material Selection Assistance: Expert guidance on grade selection for specific applications based on service conditions

• Machining Recommendations: Technical guidance on speeds, feeds, and tooling for optimal machinability

• Welding Support: Procedure recommendations and parameter optimization

• Heat Treatment Guidance: For solution annealing, aging, or stress relieving requirements

• Failure Analysis: Investigation and analysis of in-service material performance issues

• Field Service: On-site technical support for critical applications

• Fabrication Support: Assistance with forming, bending, and joining processes

Delivery Commitment

• Stock Items: Ready stock available for standard sizes and common grades (800, 825)

• Standard Orders: 6-8 weeks for standard dimensions

• Mill Orders: 8-12 weeks for non-standard dimensions, specialty grades, or special certification requirements

• Express Service: Expedited processing available for urgent requirements

• Just-in-Time (JIT) Delivery: Coordinated delivery schedules to support lean manufacturing

• Global Logistics: International shipping with full export documentation, customs clearance support

Quality Assurance

All Incoloy alloy bars are manufactured in accordance with strict quality management systems, certified to ISO 9001:2015 and applicable industry standards. Production facilities maintain:

• Advanced Melting Capabilities: AOD (Argon Oxygen Decarburization), VIM (Vacuum Induction Melting), and secondary refining for optimal purity

• Thermomechanical Processing: Optimized hot working (rolling/forging) and heat treatment cycles

• Precision Finishing: State-of-the-art cold drawing, grinding, and turning equipment

• Comprehensive Testing: In-house laboratories with full mechanical, chemical, and non-destructive testing capabilities

• PMI Testing: Positive Material Identification available for verification

Industry-Specific Certifications Available

• Aerospace: AS9100, AMS specifications (AMS 5731, 5732, 5734, 5737, 5766)

• Oil & Gas: NACE MR0175/ISO 15156 compliance, API 6A, API 6ACRA

• Pressure Equipment: PED (Pressure Equipment Directive), ASME Code (SB-408, SB-425)

• Defense: ITAR compliance, MIL-SPEC certifications where applicable

• Nuclear: NQA-1, 10CFR50 Appendix B (select facilities)