Mechanical properties — σ_y(T)

Yield strength vs temperature curve (ASME II Part D)

Plot the temperature-dependent yield strength of an alloy, with the ASME allowable stress curve overlaid. Quick check for elevated-temperature design pressure / wall sizing.

Inputs

Material preset

Sy at room TMPa

T_softening start°C

Below this Sy is roughly constant; above, decay begins.

T_max design°C

Code maximum service temperature per ASME II Part D / B31.3 Table A-1.

Operating T°C

sour-service SS

Results

σ_y(T) — yield strength vs temperature

Sy(T_op=200°C) ≈ 207 MPa · ASME allowable ≈ 138 MPa · softening above 540°C

Sy at operating T207MPa

Sy(T_op)/Sy(RT) ratio1.000

ASME allowable σ_a (≈Sy/1.5)138MPa

VerdictCOLD — full Sy retained

The Sy decay model assumes 30 % retention at T_max_design; actual values from ASME II Part D Table 2A vary per alloy. For creep regime (T > 0.4·T_melt) Sy alone is insufficient — switch to Larson-Miller / time-dependent allowable.

Download all inputs + calculations + outputs as a single PDF.