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GB · China · 1 designation

12CrNi3A

12CrNi3A is a grade designated under GB. Its recorded composition includes C 0.1–0.17%, Si 0.17–0.37%, Cr 0.6–0.9%, Mn 0.3–0.6% and Ni 2.75–3.15%. No cross-standard equivalents are recorded for this grade yet.

Chemical composition

9 elements on file · weight %

What this alloy is

Iron — the balance, never listed by a standard — 95 %Ni — 3 %Cr — 0.8 %Mn — 0.4 %Traces & impurities · 0.8 %

Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade.

Element% by weight
0.1–0.17
0.17–0.37
0.3–0.6
≤ 0.025
≤ 0.025
0.6–0.9
≤ 0.1
2.75–3.15
≤ 0.25
CarbonSiliconManganesePhosphorusSulfurChromiumMolybdenumNickelCopper
0.01 %0.1 %1 %10 %100 %

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.

ElementAs publishedsource text, verbatimMin% by weightMax% by weightBound
C0.1-0.170.1000.170Range
Si0.17-0.370.1700.370Range
P≤0.0250.025Max
S≤0.0250.025Max
Cr0.6-0.90.6000.900Range
Mn0.3-0.60.3000.600Range
Ni2.75-3.152.7503.150Range
Cu≤0.250.250Max
Mo≤0.10.100Max

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 · °C
Predicted Ae3775°C
Predicted Ae1698°C
Predicted Acm411°C
Predicted Bs524°C

These 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.

Looking for this grade under another name?

Search the catalogue by designation, material number or composition — every name on this page is itself a way in.