20CrNiMoA
20CrNiMoA is a grade designated under GB. Its recorded composition includes C 0.17–0.23%, Si 0.17–0.37%, Cr 0.4–0.7%, Mn 0.6–0.95% and Ni 0.35–0.75%. No cross-standard equivalents are recorded for this grade yet.
- Designations 1
Chemical composition
9 elements on file · weight %What this alloy is
Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade.
| Element | % by weight |
|---|---|
0.17–0.23 | |
0.17–0.37 | |
0.6–0.95 | |
≤ 0.025 | |
≤ 0.025 | |
0.4–0.7 | |
0.2–0.3 | |
0.35–0.75 | |
≤ 0.25 |
The scale is logarithmic, not the element’s raw share of the alloy — the only honest way to fit 0.01 % and 100 % in one picture, and it means every value here can be compared with every other.
| Element | As publishedsource text, verbatim | Min% by weight | Max% by weight | Bound |
|---|---|---|---|---|
| C | 0.17-0.23 | 0.170 | 0.230 | Range |
| Si | 0.17-0.37 | 0.170 | 0.370 | Range |
| P | ≤0.025 | — | 0.025 | Max |
| S | ≤0.025 | — | 0.025 | Max |
| Cr | 0.4-0.7 | 0.400 | 0.700 | Range |
| Mn | 0.6-0.95 | 0.600 | 0.950 | Range |
| Ni | 0.35-0.75 | 0.350 | 0.750 | Range |
| Cu | ≤0.25 | — | 0.250 | Max |
| Mo | 0.2-0.3 | 0.200 | 0.300 | Range |
The published column is the source string byte-for-byte, decimal comma and all; Min and Max are the parsed bounds. Elements not listed have no value on file — they are omitted, never inferred.
Predicted transformation temperatures
computed from composition · °CThese four temperatures are a CALCULATION from this grade's own composition, using the published Li, Niebuhr, Meekisho & Atteridge (1998) model — never a measurement, and computed from the UPPER BOUND of each element's specified range, not a mid-range figure. Where this grade also has a measured transformation point (Ac1, Ac3, Ar1, Ar3) on file, it is shown separately, in Physical & mechanical properties, and is never replaced by the predicted figures here — Ae (predicted, equilibrium) and Ac/Ar (measured, on heating or cooling) are different physical quantities and can differ by tens of degrees; a mismatch between the two is not an error in either.
Physical & mechanical properties
An absent property means we hold no value for it — it is left out rather than estimated, interpolated from a neighbouring grade, or filled from a handbook. It does not mean the property is undefined for the material.
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