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A516 Gr.70

ASTM A516

Pressure VesselASTM Carbon PV

A516 Gr.70 is a pressure-vessel steel (Carbon PV family) to ASTM A516. It has a specified 0.2 % proof stress of 260 MPa and a typical tensile strength of about 485 MPa, with a uniform elongation of 21 %. Nominal carbon content is around 0.31 %. For nonlinear FEA, a bilinear model uses E = 210 GPa up to yield and a tangent modulus of 1088 MPa above it. A plain-carbon steel: economical and predictable, strengthened by carbon content and heat treatment rather than alloying.

0.2% proof Rp0.2
260MPa
UTS Rm (typ)
485MPa
Uniform elong. εu
21.0%
Condition / basis
all t

Bilinear material model — nonlinear FEA

Elastic modulus E
210GPa
0.2% proof Rp0.2
260MPa
UTS Rm (typ)
485MPa
Tangent modulus Et
1088MPa

Uniform elongation εu = 21.0% · conservative analysis limit ½εu = 10.5%

Bilinear (BISO) approximation. Elastic modulus E up to the 0.2% proof stress R_p0.2, then a single tangent slope Eₜ to the ultimate tensile strength: Eₜ = (Rₘ − R_p0.2) / (εu − R_p0.2/E − 0.002), where εu is the uniform elongation and Rₘ is a typical (nominal) UTS within the specified band. The half-εu figure is a conservative strain limit for the analysis. Treat these as guidance for first-pass models; for critical work use a measured true stress–strain curve for the actual product and condition.

Ratings — engineering judgement

Weldabilitymoderate

Medium carbon (~0.31%) — preheat and hydrogen-controlled consumables advisable, especially in thicker sections.

Machinabilitygood

Machines well, particularly in the normalised or pre-tempered condition.

Corrosion resistancepoor

No inherent corrosion resistance — protect by paint, galvanising or plating in exposed use.

Hardenabilitygood

Responds well to quench-and-temper (and, for the case-hardening/nitriding grades, to surface treatment).

Toughnessmoderate

Adequate toughness for general use at ambient temperature.

Indicative ratings derived from composition and family — engineering guidance, not specification values.

Physical properties

Density7850kg/m³
Elastic modulus210GPa
Shear modulus80.8GPa
Poisson's ratio0.30
Thermal expansion12.0×10⁻⁶/°C
Thermal conductivity48W/(m·K)
Specific heat470J/(kg·K)
MagneticYes

Typical values for astm carbon pv steel — use the mill certificate for the specific product.

Chemical composition (wt %)

C
≤ 0.31*
Mn
0.60–1.30
Si
0.15–0.40
P
≤ 0.035
S
≤ 0.035

Typical composition per ASTM A516 (*C max is grade- and thickness-dependent).

Available forms

plateexcellent
boiler & vessel plate
Primary form, certified to the vessel code.
forginggood
flanges, heads
For nozzles and heavy sections.

Common applications

  • Boilers and pressure vessels
  • Storage tanks and process drums
  • Heat exchanger shells
  • Piping components (to code)

History

The ASTM pressure-vessel plates (A516 carbon, A537 fine-grain) are the North-American counterparts to the EN P-grades, specified throughout the ASME Boiler & Pressure Vessel Code. Grade 70 — the ASTM grade number is the minimum tensile strength in ksi (Gr.70 ≈ 485 MPa tensile).

  1. 1915
    ASME Boiler & Pressure Vessel Code first issued
  2. 1960
    ASTM A516 becomes the standard carbon vessel plate

This profile is generated from the grade's core data and family. Composition is decoded from the designation where its naming system defines it; physical properties are family-typical and ratings are indicative. Confirm critical values against the governing standard or the mill certificate. Equivalents, historical designations and hand-written expert notes are added per grade over time.