Intergranular attack practice selection and corrosion-rate calculation (A262), and pitting/crevice corrosion test parameters (G48)
◉ ASTM A262-02ae3 · G48-11(2015) · NOT A REGULATORY SUBMISSION TOOL
⚠ Both editions are superseded — G48 significantly so. A262-02 is well behind the current A262-15(2021). G48-11(2015) is behind the current G48-25, published October 2025. Both standards are read directly from the editions supplied. Neither standard states universal pass/fail corrosion-rate or mass-loss limits itself — both explicitly leave acceptance criteria to the purchaser's material specification or the referencing code. This tool computes the test result (corrosion rate, or a suggested starting test temperature); it does not judge whether that result is acceptable.
Identification
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1. A262 — Which Practice Applies?
2. A262 — Practice Parameters
3. A262 — Corrosion Rate Calculator (§14.1, Eq 1)
mm/month = (7290 × W) / (A × t × d) (§14.1, Eq 1). Do not include the depth of any pits or areas of local attack outside the general surface in this calculation — it is a general (weight-loss) corrosion rate.
4. G48 — Method Selection & Test Temperature
5. G48 Methods D/F — Estimated Starting Test Temperature (§11.1.4, Eq 2)
CCT (\u00b0C) = (1.5 \u00d7 %Cr) + (1.9 \u00d7 %Mo) + (4.9 \u00d7 %Nb) + (8.6 \u00d7 %W) − 36.2 (§11.1.4, Eq 2), for nickel-base alloys. Test at the nearest 5\u00b0C increment; test range is 0\u201385\u00b0C. Crevice/pitting attack is considered present at 0.025 mm (0.001 in.) depth or greater.