ASTM A959:2011 431: Martensitic stainless steel type 431 (UNS S43100) with the composition limits of ASTM A959-11. Carbon up to 0.20% and chromium 15.0-17.0%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Cr
Mn
Ni
P
S
Si
<=0.20
15.0-17.0
<=1.00
1.25-2.50
<=0.040
<=0.030
<=1.00
More data from ASTM A959:2011
From the standard
Other composition limitsfrom Table 1 and its footnotes
UNS number
S43100
Metallurgical class
Martensitic grade: can be hardened by heat treating and quenching and then tempered; delivered annealed or hardened and tempered
Type
431 (designation originally assigned by the American Iron and Steel Institute)
Values
Maximum unless a range or minimum is shown; where two limits are shown for the same element in one grade the more stringent applies
These are the recommended composition limits of the A959 guide, intended for adoption by standards for stainless steel products; they are not a product specification.
Source: ASTM A959:2011, Table 1 and its footnotes
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