--- title: "Z20CNS25.04 — Heat resistant steels" description: "Z20CNS25.04 in AFNOR: material number 1.4821, also listed as X15CrNiSi25-4. Category: Heat resistant steels. Designations recorded for this grade: 5." canonical: https://steelequivalents.com/materials/afnor/z20cns25-04 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/afnor/z20cns25-04.md cs: https://steelequivalents.com/cs/materiály/afnor/z20cns25-04.md de: https://steelequivalents.com/de/werkstoffe/afnor/z20cns25-04.md es: https://steelequivalents.com/es/materiales/afnor/z20cns25-04.md fr: https://steelequivalents.com/fr/matériaux/afnor/z20cns25-04.md hu: https://steelequivalents.com/hu/anyagok/afnor/z20cns25-04.md it: https://steelequivalents.com/it/materiali/afnor/z20cns25-04.md nl: https://steelequivalents.com/nl/materialen/afnor/z20cns25-04.md pl: https://steelequivalents.com/pl/materiały/afnor/z20cns25-04.md pt: https://steelequivalents.com/pt/materiais/afnor/z20cns25-04.md ru: https://steelequivalents.com/ru/материалы/afnor/z20cns25-04.md tr: https://steelequivalents.com/tr/malzemeler/afnor/z20cns25-04.md zh: https://steelequivalents.com/zh/材料/afnor/z20cns25-04.md ja: https://steelequivalents.com/ja/材料/afnor/z20cns25-04.md ar: https://steelequivalents.com/ar/المواد/afnor/z20cns25-04.md ko: https://steelequivalents.com/ko/재료/afnor/z20cns25-04.md pt-br: https://steelequivalents.com/pt-br/materiais/afnor/z20cns25-04.md hi: https://steelequivalents.com/hi/सामग्री/afnor/z20cns25-04.md content_hash: sha256:26951573454b42e8a5749aaeb9ace00ee283890afabdaf4e9cb5540e136db80f 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/z20cns25-04 > Canonical URL: https://steelequivalents.com/materials/afnor/z20cns25-04 > 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 · 5 designations # Z20CNS25.04 Z20CNS25.04 is a designation in AFNOR for the material held under material number 1.4821, also listed as X15CrNiSi25-4. It is a material in the category Heat resistant steels. We list 5 designations recorded for this grade, in the standards DIN / EN, AFNOR, SRPS and PN. - [*Material no.* **1.4821**](/materials/material-no/1.4821 "Material no.: 1.4821") - [*Category* **Heat resistant steels · 64 grades**](/categories/heat-resistant-steels "Category: Heat resistant steels · 64 grades") - *Designations* **5** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=70efd19c-3404-44fc-a3e2-e04ea96a3f74&designation=cd06a809-cbe5-4642-95df-d16dd1c885fa "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/afnor/z20cns25-04.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN X15CrNiSi25-4 This grade’s own name](/materials/din-en/x15crnisi25-4 "DIN / EN X15CrNiSi25-4") ## 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 5 designations · 4 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 - [X15CrNiSi25-4 This grade’s own name](/materials/din-en/x15crnisi25-4 "DIN / EN X15CrNiSi25-4") - [X20CrNiSi25-4 This grade’s own name Withdrawn](/materials/din-en/x20crnisi25-4 "DIN / EN X20CrNiSi25-4") AFNOR France · 1 - **Z20CNS25.04 Indicative** SRPS Serbia · 1 - [Č.4586 Indicative](/materials/srps/c-4586 "SRPS Č.4586") PN Poland · 1 - [H26N4 Indicative](/materials/pn/h26n4 "PN H26N4") 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 Mn Iron — the balance, never listed by a standard — 66.5 % Cr — 25.5 % Ni — 4.5 % Mn — 2 % Traces & impurities · 1.5 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.1–0.2 | | Si | 0.8–1.5 | | Mn | ≤ 2 | | P | 0.04 | | S | 0.015 | | Cr | 24.5–26.5 | | Ni | 3.5–5.5 | | 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 | 0,10-0,20 | 0.100 | 0.200 | Range | | N | 0,11 | 0.110 | 0.110 | Exact | | Si | 0,80-1,50 | 0.800 | 1.500 | Range | | P | 0,04 | 0.040 | 0.040 | Exact | | S | 0,015 | 0.015 | 0.015 | Exact | | Cr | 24,5-26,5 | 24.500 | 26.500 | Range | | Mn | ≤2,00 | — | 2.000 | Max | | Ni | 3,50-5,50 | 3.500 | 5.500 | 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 7,7 g/cm³ Exact 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 1 conditions · 1 values By delivery state**Solution annealed** source `steelnumber` | Delivery state | HB | |---|---| | Solution annealed | 235 | 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. [X12CrNi26-5 1.4820 Cr 24,8-27,2 · Ni 4,10-5,90 - ΔCr 0.50 - ΔNi 0.50 - 1 designations](/materials/din-en/x12crni26-5 "X12CrNi26-5") ## 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=70efd19c-3404-44fc-a3e2-e04ea96a3f74&designation=cd06a809-cbe5-4642-95df-d16dd1c885fa "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/afnor/z20cns25-04.pdf "Datasheet as PDF")