What is ASTM B670 Standard?
ASTM B670 / ASME SB 670 Standard Specification for Precipitation-Hardening Nickel Alloy (UNS N07718) Plate, Sheet, and Strip for High-Temperature Service. This specification covers rolled precipitation hardening nickel alloy (UNS N07718) plate, sheet, and strip in the annealed condition (temper) for high-temperature service.
ASTM B670 Inconel 718 Chemical Composition and Properties:
ASTM B670 contains only one material: Inconel 718 (UNS N07718/2.4668). Nickel alloy 718 is a precipitation strengthened superalloy. It itself has very good high temperature resistance and corrosion resistance. Through solution treatment and aging treatment, it can obtain very high high temperature strength. Therefore, it is often used in many extreme environments.
- Nickel (Ni): Approximately 50-55%
- Chromium (Cr): Approximately 17-21%
- Iron (Fe): Approximately 18.5% (minimum)
- Niobium (Nb): Approximately 4.75-5.5%
- Molybdenum (Mo): Approximately 2.8-3.3%
- Titanium (Ti): Approximately 0.65-1.15%
- Aluminum (Al): Approximately 0.2-0.8%
- Carbon (C): Maximum 0.08%
- Manganese (Mn): Maximum 0.35%
- Silicon (Si): Maximum 0.35%
- Sulfur (S): Maximum 0.015%
- Phosphorus (P): Maximum 0.015%
ASME SB 670 Inconel 718 Plate, Sheet, and Strip Tensile Properties:
| Nominal Thickness, in. (mm) |
Tensile Strength min, ksi (MPa) |
Yield Strength (0.2% offset) min. ksi (MPa) |
Elongation in 2 in. or 50 mm (or 4D), min, % |
|
|---|---|---|---|---|
| Inconel 718 (UNS N07718) | ||||
| Up to 1.0 (25.4), incl | 180 (1241) | 150 (1034) | 12 | |
| Over 1.0 to 2.25 (25.4 to 57.2), incl |
180 (1241) | 150 (1034) | 10 | |
ASTM B670 Applies To Sheet, Plate, Coil And Strip
Generally speaking, the thickness is 0.25 to 6.4mm, and the material produced by cold rolling is defined as alloy 718 sheet. And the thickness is 4.8 to 57.2mm, and the material produced by hot rolling is defined as alloy 718 plate. The coil is a rolled sheet or plate. The width of the alloy 718 strip is much narrower than that of the alloy 718 coil. It can be obtained by slitting the coil, or it can be obtained directly by cold rolling. Strip tends to have higher strength.
ASTM B670 Dimensions and tolerances (ASTM B906)
| Measured 3/8 in. (9.5 mm) or more from either edge except for strip under 1 in. (25.4 mm) in width which is measured at any place. | ||||
|---|---|---|---|---|
| Specified Thickness, in. (mm), incl | Sheet | |||
| Hot-Rolled | Cold-Rolled | |||
| 48 (1220) and Under | Over 48 to 60 (1220 to 1520), incl | 48 (1220) and Under | Over 48 to 60 (1220 to 1520), incl | |
| 0.018 to 0.025 (0.5 to 0.6) | 0.003 (0.08) | 0.004 (0.10) | 0.002 (0.05) | 0.003 (0.08) |
| Over 0.025 to 0.034 (0.6 to 0.9) | 0.004 (0.10) | 0.005 (0.13) | 0.003 (0.08) | 0.004 (0.10) |
| Over 0.034 to 0.043 (0.9 to 1.1) | 0.005 (0.13) | 0.006 (0.15) | 0.004 (0.10) | 0.005 (0.13) |
| Over 0.043 to 0.056 (1.1 to 1.4) | 0.005 (0.13) | 0.006 (0.15) | 0.004 (0.10) | 0.005 (0.13) |
| Over 0.056 to 0.070 (1.4 to 1.8) | 0.006 (0.15) | 0.007 (0.18) | 0.005 (0.13) | 0.006 (0.15) |
| Over 0.070 to 0.078 (1.8 to 1.9) | 0.007 (0.18) | 0.008 (0.20) | 0.006 (0.15) | 0.007 (0.18) |
| Over 0.078 to 0.093 (1.9 to 2.4) | 0.008 (0.20) | 0.009 (0.23) | 0.007 (0.18) | 0.008 (0.20) |
| Over 0.093 to 0.109 (2.4 to 2.8) | 0.009 (0.23) | 0.010 (0.25) | 0.007 (0.18) | 0.009 (0.23) |
| Over 0.109 to 0.125 (2.8 to 3.2) | 0.010 (0.25) | 0.012 (0.31) | 0.008 (0.20) | 0.010 (0.25) |
| Over 0.125 to 0.140 (3.2 to 3.6) | 0.012 (0.31) | 0.014 (0.36) | 0.008 (0.20) | 0.010 (0.25) |
| Over 0.140 to 0.171 (3.6 to 4.3) | 0.014 (0.36) | 0.016 (0.41) | 0.009 (0.23) | 0.012 (0.31) |
| Over 0.171 to 0.187 (4.3 to 4.8) | 0.015 (0.38) | 0.017 (0.43) | 0.010 (0.25) | 0.013 (0.33) |
| Over 0.187 to 0.218 (4.8 to 5.5) | 0.017 (0.43) | 0.019 (0.48) | 0.011 (0.28) | 0.015 (0.38) |
| Over 0.218 to 0.234 (5.5 to 5.9) | 0.018 (0.46) | 0.020 (0.51) | 0.012 (0.31) | 0.016 (0.41) |
| Over 0.234 to 0.250 (5.9 to 6.4) | 0.020 (0.51) | 0.022 (0.56) | 0.013 (0.33) | 0.018 (0.46) |
| Measured 3/8 in. (9.5 mm) or more from either edge except for strip under 1 in. (25.4 mm) in width which is measured at any place. Standard sheet tolerances apply for thicknesses over 0.125 in. (3.2 mm) and for all thicknesses of strip over 12 in. (305 mm) wide. |
||||
| Cold-Rolled | ||||
| Up to 0.050 (1.27), incl | 0.0015 (0.038) | |||
| Over 0.050 to 0.093 (1.27 to 2.39) | 0.0025 (0.063) | |||
| Over 0.093 to 0.125 (2.39 to 3.18) | 0.004 (0.11) | |||
| Outside Diameter, in. (mm) | Cut Length, in. (mm) | |
|---|---|---|
| Over | Under | |
| Under 2 (50.8) | 1/8 (3.2) | 0 |
| 2 (50.8) and over | 3/16 (4.8) | 0 |
| Specified Thickness, in. (mm) | Specified Width, in. (mm) | Permissible Variations in Specified Width, in. (m) | |
|---|---|---|---|
| Plus | Minus | ||
| Sheet | |||
| Up to 0.250 (6.35) | All | 0.125 (3.18) | 0 |
| Strip | |||
| Under 0.075 (1.9) | Up to 12 (305), incl | 0.007 (0.18) | 0.007 (0.18) |
| Over 12 to 48 (305 to 1219), incl | 0.062 (1.6) | 0 | |
| 0.075 to 0.100 (1.9 to 2.5), incl | Up to 12 (305), incl | 0.009 (0.23) | 0.009 (0.23) |
| Over 12 to 48 (305 to 1219), incl | 0.062 (1.6) | 0 | |
| Over 0.100 to 0.125 (2.5 to 3.2), incl | Up to 12 (305), incl | 0.012 (0.30) | 0.012 (0.30) |
| Over 12 to 48 (305 to 1219), incl | 0.062 (1.6) | 0 | |
| Over 0.125 to 0.160 (3.2 to 4.1), incl | Up to 12 (305), incl | 0.016 (0.41) | 0.016 (0.41) |
| Over 12 to 48 (305 to 1219), incl | 0.062 (1.6) | 0 | |
| Over 0.160 to 0.187 (4.1 to 4.7), incl | Up to 12 (305), incl | 0.020 (0.51) | 0.020 (0.51) |
| Over 12 to 48 (305 to 1219), incl | 0.062 (1.6) | 0 | |
| Over 0.187 to 0.250 (4.7 to 6.4), incl | Up to 12 (305), incl | 0.062 (1.6) | 0.062 (1.6) |
| Over 12 to 48 (305 to 1219), incl | 0.062 (1.6) | 0.062 (1.6) | |
Production Processes Heat Treatment:
ASME SB 670 UNS N07718 can be significantly increased in strength by aging treatment. Supplier needs to ensure that the material can reach the mechanical properties specified in the above table after aging treatment. For Inconel Alloy 718 plate, precipitation heat treatment (aging treatment) shall consist of heating to 1325±25°F (718±14°C), hold at temperature for 8 h, furnace cool to 1150±25°F (621±14°C), hold until total aging treatment time has reached 18 h, and then air cool.
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ASTM B670 UNS N07718 Plates Applications:
- Electronics: for plating electrical contacts, connectors, and printed circuit boards.
- Chemical processing: for lining tanks, vessels, and piping systems exposed to corrosive environments.
- Aerospace: for components requiring high strength, corrosion resistance, and conductivity.
- Automotive: for decorative trim, fuel cell components, and exhaust systems.
