--- title: "B444 — Heat resistant steels" description: "B444 in ASTM: material number 2.4856, also listed as NiCr22Mo9Nb. Category: Heat resistant steels. Designations recorded for this grade: 24." canonical: https://steelequivalents.com/materials/astm/b444 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/astm/b444.md cs: https://steelequivalents.com/cs/materiály/astm/b444.md de: https://steelequivalents.com/de/werkstoffe/astm/b444.md es: https://steelequivalents.com/es/materiales/astm/b444.md fr: https://steelequivalents.com/fr/matériaux/astm/b444.md hu: https://steelequivalents.com/hu/anyagok/astm/b444.md it: https://steelequivalents.com/it/materiali/astm/b444.md nl: https://steelequivalents.com/nl/materialen/astm/b444.md pl: https://steelequivalents.com/pl/materiały/astm/b444.md pt: https://steelequivalents.com/pt/materiais/astm/b444.md ru: https://steelequivalents.com/ru/материалы/astm/b444.md tr: https://steelequivalents.com/tr/malzemeler/astm/b444.md zh: https://steelequivalents.com/zh/材料/astm/b444.md ja: https://steelequivalents.com/ja/材料/astm/b444.md ar: https://steelequivalents.com/ar/المواد/astm/b444.md ko: https://steelequivalents.com/ko/재료/astm/b444.md pt-br: https://steelequivalents.com/pt-br/materiais/astm/b444.md hi: https://steelequivalents.com/hi/सामग्री/astm/b444.md content_hash: sha256:bc33805ca1d5d0121c3d6e3cb977299defaa2bbc9bc1360f18076ce8a05b65e4 generated: 2026-09-24 --- > **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/astm/b444 > Canonical URL: https://steelequivalents.com/materials/astm/b444 > 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. ASTM · United States · 24 designations # B444 B444 is a designation in ASTM for the material held under material number 2.4856, also listed as NiCr22Mo9Nb. It is a material in the category Heat resistant steels. We list 24 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, ASTM, AFNOR and SAE AMS. - [*Material no.* **2.4856**](/materials/material-no/2.4856 "Material no.: 2.4856") - [*Category* **Heat resistant steels · 64 grades**](/categories/heat-resistant-steels "Category: Heat resistant steels · 64 grades") - *Designations* **24** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=2c83a9b8-6d35-47d7-bf9b-eeba08b9bd08&designation=eeb94bb8-4c40-44ae-b72a-3795071ec45a "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/astm/b444.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN NiCr22Mo9Nb This grade’s own name · 3 grades on that route](/materials/din-en/nicr22mo9nb "DIN / EN NiCr22Mo9Nb") - [UNS N06625 This grade’s own name · 4 grades on that route](/materials/uns/n06625 "UNS N06625") ## 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 24 designations · 6 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 · 1 - [NiCr22Mo9Nb This grade’s own name](/materials/din-en/nicr22mo9nb "DIN / EN NiCr22Mo9Nb") UNS United States · 4 - [N06625 This grade’s own name](/materials/uns/n06625 "UNS N06625") - [N06626 This grade’s own name](/materials/uns/n06626 "UNS N06626") - [N26010 This grade’s own name](/materials/uns/n26010 "UNS N26010") - [N26625 Indicative](/materials/uns/n26625 "UNS N26625") AISI / SAE United States · 1 - [5581 Indicative](/materials/aisi-sae/5581 "AISI / SAE 5581") ASTM United States · 12 - [B 366 Indicative](/materials/astm/b366 "ASTM B 366") - [B 443 Indicative](/materials/astm/b-443 "ASTM B 443") - [B 443 Gr 1 Indicative](/materials/astm/b-443-gr-1 "ASTM B 443 Gr 1") - [B 446 Indicative](/materials/astm/b-446 "ASTM B 446") - [B 564 Indicative](/materials/astm/b564 "ASTM B 564") - **B444 Indicative** - [B704 Indicative](/materials/astm/b704 "ASTM B704") - [B705 Indicative](/materials/astm/b705 "ASTM B705") - [B751 Indicative](/materials/astm/b751 "ASTM B751") - [B775 Indicative](/materials/astm/b775 "ASTM B775") - [B829 Indicative](/materials/astm/b829 "ASTM B829") - [F3056 Indicative](/materials/astm/f3056 "ASTM F3056") AFNOR France · 1 - [NC 22 FeDNB Indicative](/materials/afnor/nc-22-fednb "AFNOR NC 22 FeDNB") SAE AMS United States / Aerospace · 5 - [5599 Indicative plate sheet strip](/materials/ams/5599 "SAE AMS 5599") - [5666 Indicative bar forging](/materials/ams/5666 "SAE AMS 5666") - [5837 Indicative wire](/materials/ams/5837 "SAE AMS 5837") - [5869 Indicative plate sheet strip](/materials/ams/5869 "SAE AMS 5869") - [5879 Indicative](/materials/ams/5879 "SAE AMS 5879") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 14 elements on file · weight % What this alloy is Fe Ni Cr Mo Iron — the balance, never listed by a standard — 4.4 % Ni — 58 % Cr — 21.5 % Mo — 9 % Traces & impurities · 7.1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.03–0.1 | | Si | ≤ 0.5 | | Mn | ≤ 0.5 | | P | 0.02 | | S | 0.015 | | Cr | 20–23 | | Mo | 8–10 — Unusual | | Ni | ≥ 58 | | Co | ≤ 1 | | Cu | ≤ 0.5 | | Al | ≤ 0.4 | | Ti | ≤ 0.4 | | Nb | 3.15–4.15 — Unusual | | Fe | ≤ 5 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Cobalt Copper Aluminium Titanium Niobium Iron 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 | 0,03-0,10 | 0.030 | 0.100 | Range | | Al | ≤0,40 | — | 0.400 | Max | | Si | ≤0,50 | — | 0.500 | Max | | P | 0,02 | 0.020 | 0.020 | Exact | | S | 0,015 | 0.015 | 0.015 | Exact | | Ti | ≤0,40 | — | 0.400 | Max | | Cr | 20,0-23,0 | 20.000 | 23.000 | Range | | Mn | ≤0,50 | — | 0.500 | Max | | Fe | ≤5,00 | — | 5.000 | Max | | Co | ≤1,00 | — | 1.000 | Max | | Ni | ≥58,0 | 58.000 | — | Min | | Cu | ≤0,50 | — | 0.500 | Max | | Nb | 3,15-4,15 | 3.150 | 4.150 | Range | | Mo | 8,00-10,0 | 8.000 | 10.000 | 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: Ni. ## Physical & mechanical properties Density 8,4 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**Soft annealed** source `steelnumber` | Delivery state | HB | |---|---| | Soft annealed | 240 | 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 2.4, a shared category, and a published range for Ni / Cr 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. [NiCr23Fe 2.4851 Ni 58,0-63,0 · Cr 21,0-25,0 - ΔNi 2.50 - ΔCr 1.50 - 21 designations](/materials/din-en/nicr23fe "NiCr23Fe") ## 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=2c83a9b8-6d35-47d7-bf9b-eeba08b9bd08&designation=eeb94bb8-4c40-44ae-b72a-3795071ec45a "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/astm/b444.pdf "Datasheet as PDF")