# Inconel 690 Forgings (UNS N06690)

Canonical page: https://www.steelforgepieces.com/Nickel-Alloy/Inconel-690.html
Manufacturer: Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory, Jiangyin, Jiangsu, China
Last updated: 19 August 2026

## Summary

Inconel 690 is a nickel-chromium-iron alloy with a minimum of 58 % nickel and 27 to 31 % chromium. The high chromium content provides resistance to stress-corrosion cracking in high-purity water, to nitric and sulphuric acid, to caustic solutions and to oxidation at temperature. Alloy 690 replaced Alloy 600 as the tube and tubesheet material in pressurised-water reactor steam generators for this reason. It is a solid-solution alloy. It is not age-hardenable and it is supplied with a low cobalt content.

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. The company manufactures Inconel 690 (UNS N06690) forgings to ASTM B564, including seamless rolled rings, flanges, tube sheets, discs, sleeves, shafts and forged bars, supplied with EN 10204 3.1 or 3.2 mill test certificates. Contact sales@steelforgepieces.com or +86 189 2135 9659.

## Designations

| Region | Designation |
| --- | --- |
| USA (UNS) | N06690 |
| Europe (W.Nr. / EN) | 2.4642, NiCr29Fe |
| Japan (JIS) | NCF690: G4901 bar, G4902 plate, G4903 pipe, G4904 tube |
| Korea (KS) | NCF690TP, D3758 |
| China (GB) | NS3105, NS315 |
| France | NY690 (Aubert & Duval) |
| Trade names | Inconel 690, Alloy 690, Nicrofer 6030, Nicrofer S 6030 and FM 690 filler |

INCONEL is a registered trademark of Special Metals Corporation. Jiangyin Jiangnan Metal supplies material manufactured to the equivalent UNS N06690 requirements and is not affiliated with the trademark owner.

## Chemical composition (wt %, ASTM B564 and B166)

| Element | Limit |
| --- | --- |
| Ni | 58.0 min |
| Cr | 27.0 to 31.0 |
| Fe | 7.0 to 11.0 |
| C | 0.05 max |
| Mn | 0.50 max |
| Si | 0.50 max |
| Cu | 0.50 max |
| S | 0.015 max |
| Co | 0.10 max (nuclear supplementary requirement only) |

## Mechanical properties, annealed, room temperature

| Property | ASTM B564 minimum | Typical achieved |
| --- | --- | --- |
| Ultimate tensile strength | 586 MPa (85 ksi) | 690 to 760 MPa |
| Yield strength, 0.2 % offset | 241 MPa (35 ksi) | 310 to 380 MPa |
| Elongation in 4D | 30 % | 40 to 50 % |
| Reduction of area | not specified | 55 to 65 % |
| Hardness | not specified | approx. 88 HRB, 170 to 190 HB |

## Physical properties at 20 C

| Property | Value |
| --- | --- |
| Density | 8.19 g/cm3 (0.296 lb/in3) |
| Melting range | 1343 to 1377 C (2450 to 2510 F) |
| Thermal conductivity | 12.1 W/m.K |
| Modulus of elasticity | approx. 211 GPa |
| Poisson's ratio | 0.29 |
| Specific heat | approx. 450 J/kg.K |
| Electrical resistivity | approx. 1.15 micro-ohm.m |
| Mean expansion 20 to 100 C | approx. 14.1 micrometre/m.K |
| Magnetic permeability | approx. 1.001, practically non-magnetic |

Typical values are indicative and must not be used for design. Certified values appear on the EN 10204 3.1 mill test certificate.

## Forging and heat treatment

- Forging range: 1038 to 1233 C (1900 to 2250 F)
- Hot working range: 872 to 1205 C
- Minimum finishing temperature: 954 C. Below this, deformation drives work hardening instead of recrystallisation and the risk of cracking rises.
- Solution annealing: approximately 1038 C (1900 F), rapid cool. This is the standard delivery condition.
- Thermal treatment (690TT): 700 to 715 C for 5 to 15 hours after solution annealing, for resistance to primary water stress-corrosion cracking in nuclear service.
- Not age-hardenable. Alloy 690 contains no gamma prime forming elements. Strength can be raised only by cold work and grain-size control. A drawing calling for solution treatment plus ageing on N06690 has usually been carried over from an Alloy 718 or Waspaloy specification and should be corrected.

## Corrosion performance

Performs well in: high-purity water at pressure (PWSCC resistance in the 690TT condition), nitric acid and nitric-hydrofluoric mixtures, caustic solutions, sulphidising and oxidising gases at temperature, chloride environments.

Another alloy is preferable in: strongly reducing acids such as hot hydrochloric (Hastelloy C-276 or Alloy 625), high-strength applications (Inconel 718 or 725), sustained load above about 650 C where creep governs (Alloy 617 or Haynes 230).

## Alloy 690 vs 600 vs 625, ASTM B564 annealed forgings

| | Inconel 690 / N06690 | Inconel 600 / N06600 | Inconel 625 / N06625 |
| --- | --- | --- | --- |
| Ni, % | 58.0 min | 72.0 min | 58.0 min |
| Cr, % | 27.0 to 31.0 | 14.0 to 17.0 | 20.0 to 23.0 |
| Mo, % | none | none | 8.0 to 10.0 |
| Tensile min | 586 MPa | 552 MPa | 827 MPa |
| Yield min | 241 MPa | 241 MPa | 414 MPa |
| Elongation min | 30 % | 30 % | 30 % |
| Oxidising acids | Excellent | Moderate | Good |
| Reducing acids | Limited | Limited | Excellent |
| PWSCC resistance | Excellent (690TT) | Poor | Good |

## Standards

ASTM B564 and ASME SB-564 (forgings, the governing specification), ASTM B166 (rod, bar, wire), ASTM B167 (seamless pipe and tube), ASTM B168 (plate, sheet, strip), ASTM B163 (heat-exchanger tube), ASTM B829 (general requirements).

## Applications

Nuclear: steam generator tubesheets and tube support plates, channel head and divider plate components, control rod drive mechanism parts, primary coolant nozzles, reactor internal rings.

Chemical: nitric acid plant vessels and valve bodies, fuel reprocessing dissolvers, caustic evaporators, heat exchanger flanges and tube sheets.

High temperature: furnace muffles and retorts, radiant tubes, petrochemical heaters, coal gasification hardware, waste vitrification melter parts.

Valves and rotating equipment: forged valve bodies, seats, stems and blocks, pump and agitator shafts, sleeves and bushings.

## Forgings supplied by Jiangyin Jiangnan Metal

| Form | Size range |
| --- | --- |
| Seamless rolled rings | OD 200 to 4000 mm, height up to 1200 mm |
| Forged flanges | DN 15 to DN 2000, Class 150 to 2500, ASME B16.5 / B16.47 / EN 1092-1 |
| Forged tube sheets | Diameter up to 3000 mm, thickness up to 400 mm |
| Forged discs | Diameter 100 to 2500 mm, thickness 20 to 600 mm |
| Forged bars | Diameter 50 to 800 mm, length up to 6000 mm |
| Forged shafts and spindles | Diameter up to 900 mm, length up to 6000 mm |
| Sleeves and bushings | OD up to 1500 mm, ID from 80 mm |
| Valve bodies, stems, seats | To drawing |

Single-piece weight 5 kg to 15 000 kg. No minimum order quantity. Typical lead time 25 to 45 days. Quotation within 24 hours of receiving a drawing.

## Testing and certification

Melting by EAF plus AOD or VOD, with ESR remelting where low inclusion content is required. Chemical analysis and PMI on every heat. Tensile testing to ASTM E8/E8M. Hardness to ASTM E10 and E18. Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388 on every piece. Liquid penetrant to ASTM E165. Intergranular corrosion to ASTM A262 or G28 A on request. Grain size to ASTM E112 on request.

EN 10204 3.1 mill test certificates as standard. EN 10204 3.2 with TUV, Bureau Veritas, SGS, Lloyd's Register or DNV witness on request. Traceability from the ingot heat number to the stamp on the finished forging.

## Contact

Jiangyin Jiangnan Metal Co., Ltd.
Open-die forging factory
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Tel: +86 189 2135 9659
Email: sales@steelforgepieces.com
Web: https://www.steelforgepieces.com/
Hours: Monday to Saturday 08:00 to 18:00 CST (UTC+8)

Technical data compiled from ASTM B564, ASTM B166 and published alloy producer datasheets.