Nickel Alloy Inconel 690 CD-SR
Heat-treated state
UNS N06690 · EN 2.4642, NiCr29Fe
CD-SR = cold drawn + stress relieved
Cold-drawn bar/tube with residual stresses reduced for dimensional stability and lower SCC risk while keeping most cold-work strength.
Values for the CD-SR condition
Other Inconel 690 tempers and conditions
Inconel 690 is listed in 7 conditions; see the grade overview at Inconel 690.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Thermally treated | Nuclear steam-generator tubing condition (Alloy 690TT) giving maximum resistance to primary-water and caustic SCC. | 320 | 700 | 45 | 165 HB | — |
ANNDefault Annealed | Standard stocked condition for plate, sheet, bar and tube — best ductility, formability and corrosion resistance. | 345 | 725 | 45 | 170 HB | — |
Hot worked / hot finished | Economical condition for heavy bar, forgings and rings where the hot-finished properties satisfy ASTM B166 minima. | 400 | 760 | 38 | 190 HB | — |
Quarter-Hard | Light cold work for slightly higher yield strength while keeping useful bending ductility in strip and tube. | 550 | 800 | 28 | 17 HRC | 1.5 % IACS |
CD-SRThis page Cold drawn + stress relieved | Cold-drawn bar/tube with residual stresses reduced for dimensional stability and lower SCC risk while keeping most cold-work strength. | 690 | 880 | 20 | 22 HRC | 1.5 % IACS |
Half-Hard | Springy strip, wire and thin-wall tube needing roughly double the annealed yield strength. | 700 | 900 | 18 | 24 HRC | — |
Full-Hard | Maximum as-drawn strength for springs, fasteners and small-diameter wire; very limited ductility and no recrystallization above ~550 °C service. | 900 | 1,070 | 8 | 32 HRC | — |
What is Inconel 690 CD-SR?
Inconel 690 CD-SR is Inconel 690 heat treated to CD-SR — cold-drawn bar/tube with residual stresses reduced for dimensional stability and lower SCC risk while keeping most cold-work strength. Inconel 690 CD-SR has a yield strength of 690 MPa (100 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 81% of nickel alloy grades. Elongation at break is 20% and the elastic modulus is 211 GPa (30.6 Msi). Inconel 690 CD-SR has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 68% of nickel alloy grades. It melts at 1,343°C (2,449 °F). ANN is the default condition FabDigit quotes; CD-SR is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 150 MPa·√m (136.5 ksi·√in), better than 93% of nickel alloy grades
- High strength — 690 MPa (100 ksi), better than 81% of nickel alloy grades
Limitations
- Limited ductility — 20%, worse than 76% of nickel alloy grades
- Limited service temperature — 540°C (1,004 °F), worse than 75% of nickel alloy grades
Inconel 690 CD-SR properties
Typical room-temperature values for Inconel 690 CD-SR; 23 are specific to this condition. Other listed values are Inconel 690 reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
Inconel 690 CD-SR has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 68% of nickel alloy grades. It melts at 1,343°C (2,449 °F).
Mechanical16
Inconel 690 CD-SR has a yield strength of 690 MPa (100 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 81% of nickel alloy grades. Elongation at break is 20% and the elastic modulus is 211 GPa (30.6 Msi).
Thermal6
Inconel 690 CD-SR is rated for continuous service to 540°C (1,004 °F). It conducts heat at 13.5 W/m·K (7.8 BTU/hr·ft·°F), better than 73% of nickel alloy grades. Thermal expansion is 14 µm/m·K (7.78 µin/in·°F).
Electrical3
Inconel 690 CD-SR conducts electricity at 1.5 % IACS, better than 59% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 74% of nickel alloy grades.
Sustainability4
Producing a kilogram of Inconel 690 CD-SR takes about 135 MJ of energy and emits 13.5 kg of CO₂ — less than 84% of nickel alloy grades. Typical recycled content is 40%.
Manufacturability8
Inconel 690 CD-SR's machinability is poor (28/100, better than 82% of nickel alloy grades); weldability very good (70/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Inconel 690 CD-SR
Is Inconel 690 easy to machine?
Treat like a gummy austenitic superalloy: rigid setups, positive-rake sharp carbide or ceramic tools, heavy constant feed to cut under the work-hardened layer, low SFM and copious high-pressure coolant.
Can Inconel 690 be welded?
Readily GTAW/GMAW/SMAW welded without preheat or PWHT; use matching ERNiCrFe-7/7A or ERNiCr-3 style high-Cr fillers, keep interpass temperature low and heat input modest to avoid hot cracking.
Can Inconel 690 be formed, bent or molded?
Cold forms well in the annealed temper but work-hardens fast — allow extra power, generous radii and intermediate anneals at 1040–1090 °C; hot work at 1090–1230 °C with finishing above ~950 °C.
What surface finishes work on Inconel 690?
Pickle or grind off the tenacious chromium oxide before welding and before any brazing/plating; electropolishing or fine mechanical polishing gives the low-crud surfaces required for nuclear service.
Inconel 690 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Ni58 % minimum per ASTM B168 | ≥ 58 | 60 |
| Cr | 27 – 31 | 29 |
| Fe | 7 – 11 | 9.5 |
| C0.015–0.025 typical for TT nuclear tubing | ≤ 0.05 | 0.02 |
| Mn | ≤ 0.5 | 0.2 |
| Si | ≤ 0.5 | 0.3 |
| Cu | ≤ 0.5 | 0.02 |
| S | ≤ 0.02 | 0 |
| Tispecified in nuclear tubing orders | ≤ 0.5 | 0.25 |
| Alsupplementary/producer limit | ≤ 0.5 | 0.2 |
Inconel 690 CD-SR — frequently asked
What is Inconel 690 CD-SR used for?
Inconel 690 CD-SR is typically used for nuclear steam generator tubing, pressurised water reactor primary-side components, reactor vessel head penetrations and nozzles, tube plugs and sleeves, nuclear waste vitrification melter parts and nitric and mixed-acid process equipment. In short: nuclear-grade SCC resistance; high-Cr upgrade of Alloy 600; good weldability, poor machinability.
What is the yield strength of Inconel 690 CD-SR?
Inconel 690 CD-SR has a typical yield strength of 690 MPa (100 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 81% of nickel alloy grades. Strength varies by condition: see the 7 listed tempers.
Is Inconel 690 CD-SR easy to machine?
Not especially — machinability is rated poor (28/100, better than 82% of nickel alloy grades). Treat like a gummy austenitic superalloy: rigid setups, positive-rake sharp carbide or ceramic tools, heavy constant feed to cut under the work-hardened layer, low SFM and copious high-pressure coolant.
Can Inconel 690 CD-SR be welded?
Yes — weldability is rated very good (70/100). Readily GTAW/GMAW/SMAW welded without preheat or PWHT; use matching ERNiCrFe-7/7A or ERNiCr-3 style high-Cr fillers, keep interpass temperature low and heat input modest to avoid hot cracking.
What surface finishes work on Inconel 690 CD-SR?
Pickle or grind off the tenacious chromium oxide before welding and before any brazing/plating; electropolishing or fine mechanical polishing gives the low-crud surfaces required for nuclear service.
Can Inconel 690 CD-SR be formed, bent or molded?
Cold forms well in the annealed temper but work-hardens fast — allow extra power, generous radii and intermediate anneals at 1040–1090 °C; hot work at 1090–1230 °C with finishing above ~950 °C.
What is the maximum service temperature of Inconel 690 CD-SR?
Inconel 690 CD-SR is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Inconel 690-ANN and Inconel 690 CW-FH?
ANN is the default condition — standard stocked condition for plate, sheet, bar and tube — best ductility, formability and corrosion resistance. CW-FH: maximum as-drawn strength for springs, fasteners and small-diameter wire; very limited ductility and no recrystallization above ~550 °C service. Yield strength is 345 MPa in ANN versus 900 MPa in CW-FH.
Sources
- INCONEL alloy 690 technical bulletin — Special Metals Corporation (2009)
- ASTM B168 — Ni-Cr-Fe alloy plate, sheet and strip — ASTM International (2019)
- ASTM B166 — Ni-Cr-Fe alloy rod, bar and wire — ASTM International (2019)
- ASME SB-163 / SB-167 (N06690 tubing, incl. thermally treated) — ASME (2021)
- GB/T 15007 / NS3105 (2017)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.