Introduction

Inconel 690 (UNS N06690 / Alloy 690) is a high‑chromium nickel alloy with excellent resistance to many corrosive media, as well as to oxidation and sulfidation in high‑temperature gaseous environments. In addition to its corrosion resistance, Alloy 690 offers high strength, good metallurgical stability, and favorable fabrication characteristics. The alloy is normally used in the annealed condition, and its behavior during cold forming is similar to that of Inconel 600. Inconel 690 round bar, seamless tube, steam generator tube, plate, sheet, strip, wire, forging, and welding wire are widely used in nuclear power plants (PWR steam generators), chemical processing, and heat exchangers. Alloy 690 heat exchanger tube and N06690 pipe provide reliable performance in high‑temperature, corrosive environments such as nitric acid and caustic service. Available in nuclear grade per ASTM B168, B166, or AMS 5871.

Chemical components

Mechanical properties

Physical properties

Inconel 690 Available Products and Standard

1. GB/T 15007 (Nickel and Nickel Alloy Plate, Strip, and Foil)

Domestic Grade: NS3105 (GB/T 15007) / Inconel 690 equivalent

Type: Sheet / Plate / Strip / Wire / Tube / Bar

Size Range:

Wire: 0.1 – 15.0 mm dia

Strip: 0.05 – 5.0 mm thick × 5 – 500 mm wide

Round Bar: 8 – 355 mm dia

Sheet / Plate: 0.5 – 180 mm thick

Seamless Tube / Pipe: Custom sizes available

Surface: Annealed, Bright, Pickled, Ground

Testing: Chemical analysis, mechanical test (tensile strength, yield strength, elongation), hardness test, intergranular corrosion test, dimensional inspection

2. ASTM B168 (Standard Specification for Nickel‑Chromium Alloy Plate, Sheet, and Strip)

Grade: UNS N06690 / Inconel 690 / Alloy 690 / W. Nr. 2.4642

Type: Sheet / Plate / Strip

Size Range:

Sheet / Plate: 0.5 – 180 mm thick (hot rolled or cold rolled)

Strip: 0.05 – 5.0 mm thick × up to 500 mm wide (coils)

Surface: Annealed, Pickled, Bright, Polished

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hardness test, intergranular corrosion test, dimensional inspection

3. ASTM B166 (Standard Specification for Nickel‑Chromium Alloy Rod and Bar)

Grade: UNS N06690 / Inconel 690 / Alloy 690

Type: Round Bar / Rod / Wire

Size Range:

Round Bar: 8 – 355 mm dia (hot rolled or cold drawn)

Wire: 0.1 – 15.0 mm dia (coils or straight)

Surface: Annealed, Pickled, Ground, Turned, Bright

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hardness test, ultrasonic test, dimensional inspection

4. ASTM B167 (Standard Specification for Nickel‑Chromium Alloy Seamless Pipe and Tube)

Grade: UNS N06690 / Inconel 690 / Alloy 690

Type: Seamless Pipe / Seamless Tube

Size Range:

Seamless Pipe: 6 – 610 mm OD × 1 – 50 mm wall thickness

Seamless Tube: Custom sizes

Surface: Annealed, Pickled, Bright

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hydrostatic test, eddy current test, dimensional inspection

Advantages

(1) Excellent stress corrosion cracking resistance – Inconel 690 steam generator tube and seamless tube resist SCC in high‑temperature, high‑purity water environments, making them ideal for PWR nuclear reactors.

(2)High‑temperature oxidation and sulfidation resistance – Alloy 690 plate and sheet perform reliably in aggressive gaseous environments at elevated temperatures, including nitric acid and caustic service.

(3)High strength and metallurgical stability – Inconel 690 round bar and forging maintain high strength and dimensional stability under thermal cycling, with cold forming behavior similar to Inconel 600.

(4)Good fabricability – N06690 wire, strip, and welding wire offer favorable welding and forming characteristics, enabling fabrication of complex components.

(5)Versatile product forms – Inconel 690 heat exchanger tube, flange, fitting, and fastener are available for chemical processing, pollution control, and nuclear applications.

Applications

(1) Nuclear power plants (PWR) – Inconel 690 steam generator tube and seamless tube are the standard material for pressurized water reactor steam generators, replacing Alloy 600 for improved SCC resistance.

(2)Chemical processing – Alloy 690 heat exchanger tube and plate handle nitric acid, mixed acids, and caustic evaporators where high chromium content provides superior corrosion resistance.

(3)Pollution control – N06690 pipe and welding wire are used in flue gas desulfurization (FGD) scrubbers, incinerator liners, and waste treatment systems.

(4)High‑temperature furnace components – Inconel 690 sheet and strip serve in radiant tubes, retorts, and furnace baffles requiring oxidation and sulfidation resistance.

(5)Aerospace and industrial gas turbines – Inconel 690 round bar and forged ring are applied in combustion chamber parts and transition ducts.

MONO Group is one of Superalloy, Nickel alloy, high Temperature alloy manufacturer&Supplier&Wholesaler from China,We can supply high quality alloy plate,sheet,round bar,tube.pipes,fittings,flange,and custom parts in accordance with ASTM, ASME, DIN, ISO, GB, and other international standards. For inquiries or to request a quote , please freely contact us at info@monokj.com.