253 MA where service is cyclic and the nickel price matters: its scale withstands heating and cooling better. 310S where the atmosphere is carburising or the temperature very high continuously.

It anchors the protective oxide layer to the metal. Without it, the scale spalls at every thermal cycle and oxidation restarts on bare metal. It is an addition of a few hundredths of a percent with a disproportionate effect.

Can it be used on a hot water heat exchanger?

No. It is a dry, hot service grade. In aqueous media a 304L or 316L performs better for far less.

GRADE PROFILE

253 MA — 1.4835 / X9CrNiSiNCe21-11-2

253 MA achieves its hot strength differently from 310S: 1.4 to 2.5% silicon and a rare-earth cerium addition, with only 10 to 12% nickel. The scale it forms resists thermal cycling better, and the alloy costs less in nickel.

Heat-resistant
PREN 22–25 †
Cost index 115

When to choose it

On industrial furnaces and combustion chambers, biomass boilers and circulating fluidised beds, high-temperature recuperators and heat exchangers, glassmaking moulds and heat treatment fixtures. Cerium anchors the oxide layer, which spalls far less under cycling — decisive on equipment that heats and cools every day.

On exhaust manifolds it is an alternative to 310S at reduced nickel content.

When not to choose it

In aqueous media of any kind. Its corrosion resistance is below that of ordinary austenitics and is not assured in contact with water. That is easily overlooked when reading a PREN of 23.

In humid hot atmospheres, where scale adhesion drops.

In forging, for which the grade is not suited.

In severe carburising atmospheres, where 310S and 314, richer in chromium and nickel, perform better.

Composition

Chemical composition (% by mass)
Element	%
C	0.05–0.12
Si	1.4–2.5
Mn	≤ 1
P	≤ 0.045
S	≤ 0.015
Cr	20–22
Ni	10–12
N	0.12–0.2
Ce	0.03–0.08

Mechanical properties

Mechanical properties
Standard	Form	Rm (MPa)	Rp0.2 (MPa)	A (%)	Hardness
EN 10296-2:2005, tableau 5	tube soudé, état hypertrempé (+AT)	≥ 650	≥ 310	≥ 40	—
EN 10297-2:2005, tableau	tube sans soudure, état hypertrempé (+AT)	≥ 650	≥ 310	—	—

Designations and standards

Equivalent normative designations
Reference	Designation
EN (numeric)	1.4835
EN (symbolic)	X9CrNiSiNCe21-11-2
ASTM / AISI	253 MA
UNS	S30815
JIS	—
AFNOR	—

Tube product standards :

EN 10095
EN 10296-2
EN 10297-2
ASTM A312/A312M
ASTM A240/A240M

Availability

Available in welded and seamless tube to EN 10095, EN 10296-2 and ASTM A312. Structured dimensional data for this grade is not yet documented in our reference set: send us your sizes. EN 10204 3.1 material certificates supplied with the goods.

Related grades

310S (1.4845) — more chromium and nickel, better in carburising atmospheres.
321 (1.4541) — the step below, to 600 °C.
Alloy 800 (N08800) — where carburisation and nitriding become the issue.

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Frequently asked questions

253 MA or 310S?: 253 MA where service is cyclic and the nickel price matters: its scale withstands heating and cooling better. 310S where the atmosphere is carburising or the temperature very high continuously.
What does cerium do?: It anchors the protective oxide layer to the metal. Without it, the scale spalls at every thermal cycle and oxidation restarts on bare metal. It is an addition of a few hundredths of a percent with a disproportionate effect.
Can it be used on a hot water heat exchanger?: No. It is a dry, hot service grade. In aqueous media a 304L or 316L performs better for far less.