--- title: "Z12CNS25.20 — Heat resistant steels" description: "Z12CNS25.20 in AFNOR: material number 1.4841, also listed as X15CrNiSi25-20. Category: Heat resistant steels. Designations recorded for this grade: 60." canonical: https://steelequivalents.com/materials/afnor/z12cns25-20 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/afnor/z12cns25-20.md cs: https://steelequivalents.com/cs/materiály/afnor/z12cns25-20.md de: https://steelequivalents.com/de/werkstoffe/afnor/z12cns25-20.md es: https://steelequivalents.com/es/materiales/afnor/z12cns25-20.md fr: https://steelequivalents.com/fr/matériaux/afnor/z12cns25-20.md hu: https://steelequivalents.com/hu/anyagok/afnor/z12cns25-20.md it: https://steelequivalents.com/it/materiali/afnor/z12cns25-20.md nl: https://steelequivalents.com/nl/materialen/afnor/z12cns25-20.md pl: https://steelequivalents.com/pl/materiały/afnor/z12cns25-20.md pt: https://steelequivalents.com/pt/materiais/afnor/z12cns25-20.md ru: https://steelequivalents.com/ru/материалы/afnor/z12cns25-20.md tr: https://steelequivalents.com/tr/malzemeler/afnor/z12cns25-20.md zh: https://steelequivalents.com/zh/材料/afnor/z12cns25-20.md ja: https://steelequivalents.com/ja/材料/afnor/z12cns25-20.md ar: https://steelequivalents.com/ar/المواد/afnor/z12cns25-20.md ko: https://steelequivalents.com/ko/재료/afnor/z12cns25-20.md pt-br: https://steelequivalents.com/pt-br/materiais/afnor/z12cns25-20.md hi: https://steelequivalents.com/hi/सामग्री/afnor/z12cns25-20.md content_hash: sha256:98a8f52af92e1319f46ca99eb7b6ad5669b1a668707ee1886378886ad133b793 generated: 2026-09-22 --- > **Machine-readable Markdown rendering.** This is a Markdown representation of a web page, > served for AI agents and crawlers as a token-efficient alternative to the full HTML. > Full interactive HTML version: https://steelequivalents.com/materials/afnor/z12cns25-20 > Canonical URL: https://steelequivalents.com/materials/afnor/z12cns25-20 > Available languages: en, cs, de, es, fr, hu, it, nl, pl, pt, ru, tr, zh, ja, ar, ko, pt-br, hi > Change detection: `content_hash` is the SHA-256 of this document's Markdown body — everything > below this block, whitespace-trimmed, excluding the front-matter. Compare it to detect a real > content change; `generated` moves on every render and is not a change signal. AFNOR · France · 60 designations # Z12CNS25.20 Z12CNS25.20 is a designation in AFNOR for the material held under material number 1.4841, also listed as X15CrNiSi25-20. It is a material in the category Heat resistant steels. We list 60 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, ASTM, BS, AFNOR, UNE, SAE AMS, JIS, GB, GOST, UNI, SS, ČSN, STN, SRPS, JUS and PN. - [*Material no.* **1.4841**](/materials/material-no/1.4841 "Material no.: 1.4841") - [*Category* **Heat resistant steels · 64 grades**](/categories/heat-resistant-steels "Category: Heat resistant steels · 64 grades") - *Designations* **60** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=1a545dd1-08e5-4d2c-8b4c-6c4a48042e8c&designation=387968da-1037-4374-8692-381b9a0413c5 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/afnor/z12cns25-20.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN X15CrNiSi25-21 This grade’s own name](/materials/din-en/x15crnisi25-21 "DIN / EN X15CrNiSi25-21") - [UNS S31000 This grade’s own name · 3 grades on that route](/materials/uns/s31000 "UNS S31000") - [AISI / SAE 310 This grade’s own name · 3 grades on that route](/materials/aisi-sae/310 "AISI / SAE 310") ## About Heat resistant steels Heat resistant steels are alloyed materials designed to retain useful mechanical properties and resist oxidation or scaling during service at elevated temperatures. They are used for components in furnaces, boilers, heat exchangers and power-generation equipment exposed to hot gases or sustained heat. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 60 designations · 18 standards · nothing hidden This grade’s own name recorded in our sources as this grade’s own designation under that standard. Indicative taken from a published cross-reference table; a close match, not a guarantee of interchangeability. Verify against the mill certificate before ordering. Withdrawn designation no longer current — a separate column from the two above, so a name can be same grade and withdrawn at once. DIN / EN Europe · 2 - [X15CrNiSi25-20 This grade’s own name Withdrawn](/materials/din-en/x15crnisi25-20 "DIN / EN X15CrNiSi25-20") - [X15CrNiSi25-21 This grade’s own name](/materials/din-en/x15crnisi25-21 "DIN / EN X15CrNiSi25-21") UNS United States · 3 - [S31000 This grade’s own name](/materials/uns/s31000 "UNS S31000") - [S31400 This grade’s own name](/materials/uns/s31400 "UNS S31400") - [S31500 Indicative](/materials/uns/s31500 "UNS S31500") AISI / SAE United States · 7 - [30310 Indicative](/materials/aisi-sae/30310 "AISI / SAE 30310") - [30314 Indicative](/materials/aisi-sae/30314 "AISI / SAE 30314") - [310 This grade’s own name](/materials/aisi-sae/310 "AISI / SAE 310") - [314 This grade’s own name](/materials/aisi-sae/314 "AISI / SAE 314") - [S31000 Indicative](/materials/uns/s31000 "AISI / SAE S31000") - [S31400 Indicative](/materials/uns/s31400 "AISI / SAE S31400") - [S31500 Indicative](/materials/uns/s31500 "AISI / SAE S31500") ASTM United States · 17 - [310 314 Indicative](/materials/astm/310-314 "ASTM 310 314") - [A1012 Indicative](/materials/astm/a1012 "ASTM A1012") - [A1049 Indicative](/materials/astm/a1049 "ASTM A1049") - [A167 Indicative](/materials/astm/a167 "ASTM A167") - [A182 Indicative](/materials/aisi-sae/a182 "ASTM A182") - [A213 Indicative](/materials/astm/a213 "ASTM A213") - [A240 Indicative](/materials/astm/a240 "ASTM A240") - [A249 Indicative](/materials/astm/a249 "ASTM A249") - [A276 Indicative](/materials/astm/a276 "ASTM A276") - [A312 Indicative](/materials/astm/a312 "ASTM A312") - [A314 Indicative](/materials/astm/a314 "ASTM A314") - [A336 Indicative](/materials/astm/a336 "ASTM A336") - [A473 Indicative](/materials/astm/a473 "ASTM A473") - [A580 Indicative](/materials/astm/a580 "ASTM A580") - [A632 Indicative](/materials/astm/a632 "ASTM A632") - [A965 Indicative](/materials/astm/a965 "ASTM A965") - [F2281 Indicative](/materials/astm/f2281 "ASTM F2281") BS United Kingdom · 2 - [310S24 Indicative](/materials/bs/310s24 "BS 310S24") - [314 S 25 Indicative](/materials/bs/314-s-25 "BS 314 S 25") AFNOR France · 3 - [Z12CN25.20 Indicative](/materials/afnor/z12cn2520 "AFNOR Z12CN25.20") - **Z12CNS25.20 Indicative** - [Z15CNS25-20 Indicative](/materials/afnor/z15cns25-20 "AFNOR Z15CNS25-20") UNE Spain · 3 - [F.3310 Indicative](/materials/une/f-3310 "UNE F.3310") - [F.3310-X15 CrNiSi 25-20 Indicative](/materials/une/f-3310-x15-crnisi-25-20 "UNE F.3310-X15 CrNiSi 25-20") - [X15CrNiSi25-20 Indicative](/materials/din-en/x15crnisi25-20 "UNE X15CrNiSi25-20") SAE AMS United States / Aerospace · 2 - [5652 Indicative](/materials/ams/5652 "SAE AMS 5652") - [7490 Indicative](/materials/ams/7490 "SAE AMS 7490") JIS Japan · 4 - [SUH310 Indicative](/materials/jis/suh310 "JIS SUH310") - [SUS 310TB Indicative](/materials/jis/sus310tb "JIS SUS 310TB") - [SUS Y 310 Indicative](/materials/jis/sus-y-310 "JIS SUS Y 310") - [SUS18 Indicative](/materials/jis/sus18 "JIS SUS18") GB China · 1 - [2Cr25Ni20 Indicative](/materials/gb/2cr25ni20 "GB 2Cr25Ni20") GOST Russia / CIS · 6 - [20Ch25N20S2 Indicative](/materials/gost/20ch25n20s2 "GOST 20Ch25N20S2") - [20KH25N20S2 Indicative](/materials/gost/20kh25n20s2 "GOST 20KH25N20S2") - [20Х25Н20С2 Indicative](/materials/gost/20kh25n20s2 "GOST 20Х25Н20С2") - [ст.20Х25Н20С2 Indicative](/materials/gost/st-20kh25n20s2 "GOST ст.20Х25Н20С2") - [Х25Н20С2 Indicative](/materials/gost/kh25n20s2 "GOST Х25Н20С2") - [ЭИ283 Indicative](/materials/gost/ei283 "GOST ЭИ283") UNI Italy · 2 - [X16CrNiSi25-20 Indicative](/materials/din-en/x16crnisi25-20 "UNI X16CrNiSi25-20") - [X25CN25-20 Indicative](/materials/uni/x25cn25-20 "UNI X25CN25-20") SS Sweden · 1 - [2376 Indicative](/materials/ss/2376 "SS 2376") ČSN Czechia · 3 - [17255 Indicative](/materials/csn/17255 "ČSN 17255") - [17265 Indicative](/materials/csn/17265 "ČSN 17265") - [17265PH Indicative](/materials/csn/17265ph "ČSN 17265PH") STN Slovakia · 1 - [17 265 Indicative](/materials/csn/17265 "STN 17 265") SRPS Serbia · 1 - [Č.4578 Indicative](/materials/srps/c-4578 "SRPS Č.4578") JUS former Yugoslavia · 1 - [Č.4578 Indicative](/materials/srps/c-4578 "JUS Č.4578") PN Poland · 1 - [H25N20S2 Indicative](/materials/pn/h25n20s2 "PN H25N20S2") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 8 elements on file · weight % What this alloy is Fe Cr Ni Si Iron — the balance, never listed by a standard — 50.1 % Cr — 25 % Ni — 20.5 % Si — 2 % Traces & impurities · 2.4 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.2 | | Si | 1.5–2.5 | | Mn | ≤ 2 | | P | 0.045 | | S | 0.015 | | Cr | 24–26 | | Ni | 19–22 | | N | 0.11 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Nickel Nitrogen 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. | Element | As published source text, verbatim | Min% by weight | Max% by weight | Bound | |---|---|---|---|---| | C | ≤0,20 | — | 0.200 | Max | | N | 0,11 | 0.110 | 0.110 | Exact | | Si | 1,50-2,50 | 1.500 | 2.500 | Range | | P | 0,045 | 0.045 | 0.045 | Exact | | S | 0,015 | 0.015 | 0.015 | Exact | | Cr | 24,0-26,0 | 24.000 | 26.000 | Range | | Mn | ≤2,00 | — | 2.000 | Max | | Ni | 19,0-22,0 | 19.000 | 22.000 | 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 Not enough recorded composition to predict a transformation temperature for this grade — missing: Mo. ## Physical & mechanical properties Density 7,9 g/cm³ Exact Temper brittleness susceptible As published: predisposed 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. ## Properties by condition 4 conditions · 23 values By delivery state**Solution annealed** source `steelnumber` | Delivery state | HB | |---|---| | Solution annealed | 223 | By dimension**Quenching 1100 - 1150°C, air** source `splav` | Dimension mm | Rm N/mm² | Re N/mm² | A5% | Z% | |---|---|---|---|---| | Ø 60 | 590 | 295 | 35 | 50 | By heat-treated condition**no delivery state stated** source `splav` | Heat-treated condition | Rm N/mm² | A5% | |---|---|---| | Sheet thin, GOST 5582-75 | 490 | 35 | At temperature**no delivery state stated** source `splav` | Temperature °C | Density g/cm³ | Thermal expansion coefficient 10^-6/K | Thermal conductivity W/(m·K) | |---|---|---|---| | 20 | 7.72 | — | — | | 100 | 7.68 | 16.1 | 15 | | 500 | — | — | 22 | | 600 | — | 17.8 | 24 | | 700 | — | 17.8 | 25 | | 800 | 7.44 | 18.1 | 27 | | 900 | 7.39 | 18.5 | 29 | | 1000 | — | 18.8 | — | Every figure holds only for the condition on its own row. Values are never merged across conditions or across sources, never averaged, and never interpolated between two rows. An em dash means no value on file — never zero. Figures are converted to the unit in the column header; the source’s own wording is kept and shown where the two differ. ## Similar grades — and why Selection rule, stated so you can disagree with it: same number class 1.4, a shared category, and a published range for Cr / Ni that overlaps this grade’s. These are neighbours in composition space — they are not equivalents, and none is claimed to be interchangeable with this grade. [1.4845 1.4845 Cr 24,0-26,0 · Ni 19,0-22,0 - ΔCr 0.00 - ΔNi 0.00 - 91 designations](/materials/material-no/1.4845 "1.4845")[X6CrNi25-20 1.4951 Cr 24,0-26,0 · Ni 19,0-22,0 - ΔCr 0.00 - ΔNi 0.00 - 34 designations](/materials/din-en/x6crni25-20 "X6CrNi25-20") ## 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. [Search](/search "Steel grade search")[Inquiry](/inquiry?material=1a545dd1-08e5-4d2c-8b4c-6c4a48042e8c&designation=387968da-1037-4374-8692-381b9a0413c5 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/afnor/z12cns25-20.pdf "Datasheet as PDF")