--- title: "12SiMoVNb — composition, equivalents and standards" description: "12SiMoVNb: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/gb/12simovnb language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/12simovnb.md cs: https://steelequivalents.com/cs/materiály/gb/12simovnb.md de: https://steelequivalents.com/de/werkstoffe/gb/12simovnb.md es: https://steelequivalents.com/es/materiales/gb/12simovnb.md fr: https://steelequivalents.com/fr/matériaux/gb/12simovnb.md hu: https://steelequivalents.com/hu/anyagok/gb/12simovnb.md it: https://steelequivalents.com/it/materiali/gb/12simovnb.md nl: https://steelequivalents.com/nl/materialen/gb/12simovnb.md pl: https://steelequivalents.com/pl/materiały/gb/12simovnb.md pt: https://steelequivalents.com/pt/materiais/gb/12simovnb.md ru: https://steelequivalents.com/ru/материалы/gb/12simovnb.md tr: https://steelequivalents.com/tr/malzemeler/gb/12simovnb.md zh: https://steelequivalents.com/zh/材料/gb/12simovnb.md ja: https://steelequivalents.com/ja/材料/gb/12simovnb.md ar: https://steelequivalents.com/ar/المواد/gb/12simovnb.md ko: https://steelequivalents.com/ko/재료/gb/12simovnb.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/12simovnb.md hi: https://steelequivalents.com/hi/सामग्री/gb/12simovnb.md content_hash: sha256:f70d11faddc992904686953a6c12b314061f2851e4a449af86258d932ce76c22 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/gb/12simovnb > Canonical URL: https://steelequivalents.com/materials/gb/12simovnb > 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. GB · China · 1 designation # 12SiMoVNb 12SiMoVNb is a grade designated under GB. Its recorded composition includes C 0.08–0.14%, Si 0.5–0.8%, V 0.3–0.5%, Mn 0.6–0.9% and Mo 0.9–1.1%. No cross-standard equivalents are recorded for this grade yet. - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=ca01d6ff-cf5b-4022-b0ee-ce56d5132944&designation=ec31d45d-ddc3-410a-81fb-25c003c944ee "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/12simovnb.pdf "Datasheet as PDF") ## Chemical composition 11 elements on file · weight % What this alloy is Fe Mo Mn Si Iron — the balance, never listed by a standard — 96.2 % Mo — 1 % Mn — 0.8 % Si — 0.7 % Traces & impurities · 1.4 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.08–0.14 | | Si | 0.5–0.8 | | Mn | 0.6–0.9 | | P | ≤ 0.025 | | S | ≤ 0.015 | | Cr | ≤ 0.3 | | Mo | 0.9–1.1 | | Ni | ≤ 0.3 | | V | 0.3–0.5 | | Cu | ≤ 0.2 | | Nb | 0.04–0.08 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Vanadium Copper Niobium 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 | 0.08-0.14 | 0.080 | 0.140 | Range | | Si | 0.5-0.8 | 0.500 | 0.800 | Range | | P | ≤0.025 | — | 0.025 | Max | | S | ≤0.015 | — | 0.015 | Max | | V | 0.3-0.5 | 0.300 | 0.500 | Range | | Cr | ≤0.3 | — | 0.300 | Max | | Mn | 0.6-0.9 | 0.600 | 0.900 | Range | | Ni | ≤0.3 | — | 0.300 | Max | | Cu | ≤0.2 | — | 0.200 | Max | | Nb | 0.04-0.08 | 0.040 | 0.080 | Range | | Mo | 0.9-1.1 | 0.900 | 1.100 | 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 computed from composition · °C Predicted Ae3 847 °C Predicted Ae1 731 °C Predicted Acm 395 °C Predicted Bs 538 °C These four temperatures are a CALCULATION from this grade's own composition, using the published Li, Niebuhr, Meekisho & Atteridge (1998) model — never a measurement, and computed from the UPPER BOUND of each element's specified range, not a mid-range figure. Where this grade also has a measured transformation point (Ac1, Ac3, Ar1, Ar3) on file, it is shown separately, in Physical & mechanical properties, and is never replaced by the predicted figures here — Ae (predicted, equilibrium) and Ac/Ar (measured, on heating or cooling) are different physical quantities and can differ by tens of degrees; a mismatch between the two is not an error in either. ## Physical & mechanical properties 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. ## Heat treatment Supply condition - Normalizing and Tempering Conditions the standard permits on delivery. No temperature or medium is published for these, so no order and no alternation is implied. Source: [www.caishuku.com](https://www.caishuku.com/detail/azhlNWIxMzM1MzM_ "Source: www.caishuku.com") ## 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=ca01d6ff-cf5b-4022-b0ee-ce56d5132944&designation=ec31d45d-ddc3-410a-81fb-25c003c944ee "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/12simovnb.pdf "Datasheet as PDF")