ASTM A672 B70
UNS K03101ASTM A672 B70 material
Key Engineering Metrics
Instant specifications summary for ASTM A672 B70
General Specifications & Standard Data
ASTM A672Minimum Design Metal Temperature rules for impact testing exemption under ASME B31.3 paragraph 323.2.2.
Mechanical Properties
Room Temp (20°C / 68°F)Allowable Stress Data (ASME B31.3 Table A-1)
asme-b31-3Allowable Stress vs Temperature
ASME B31.3 / BPVC Section II Part D Reference Curve
| Temperature (°C) | Allowable Stress (MPa) | % of Room Temp Rating |
|---|---|---|
| 38 | 137.9 | 100% |
| 100 | 137.9 | 100% |
| 150 | 137.9 | 100% |
| 200 | 131.0 | 95% |
| 250 | 122.0 | 88% |
| 300 | 115.0 | 83% |
| 350 | 112.0 | 81% |
| 400 | 108.0 | 78% |
| 450 | 105.0 | 76% |
| 500 | 102.0 | 74% |
Chemical Composition (% Weight)
Heat & Product Analysis🛡️ Service Compatibility
Industry standard for crude oil, natural gas, LPG, and refined fuels up to 425°C.
Excellent for non-corrosive steam ≤425°C (800°F). Risk of graphitization above 425°C.
Standard for treated boiler feed & cooling water. Untreated water requires corrosion allowance.
Requires NACE MR0175 / ISO 15156 compliance, hardness ≤22 HRC, and HIC/SSC testing.
Risk of brittle failure below -29°C (-20°F). Use LTCS (A333 Gr. 6).
High uniform corrosion rate without lining or cathodic protection.
🔥 Welding & Heat Treatment
10°C min for wall thickness t ≤ 25mm; 95°C (200°F) preheat required for t > 25mm or C > 0.30% per ASME B31.3 Table 330.1.1.
Required if nominal wall thickness t > 19mm (0.75 in) per ASME B31.3 Table 331.1.1 (holding temp 600°C–650°C for 1 hr/in).
Exempt down to -29°C (-20°F) per ASME B31.3 Fig 323.2.2A Curve B. Impact test required if MDMT is lower.
Material property data provided is for preliminary engineering reference. Always verify properties against the latest ASME BPVC Section II, ASTM material specification, and Material Test Report (MTR/MTC).