What “the material” actually is
鋼 is sold as grades, not as a single substance. Chemistry Fe–C (±Mn, Si, Cr…), density 7.85 g/cm³, heat band 1370–1530 °C.
This atlas treats 鋼 as a system: mill route, coatings, tests and the cavity it sits in.
基本データ
7.85 g/cm³Density
1370–1530 °CMelting
~200 GPaE-modulus
Euroclass A1Fire
Highly recyclableLoop
metalsFamily
鋼 is one of 32 materials in this atlas, grouped under metals: history, structure, measured properties, process routes, uses, safety and market — not a product catalogue.
Scores compare 鋼 with the rest of the atlas on strength, heat, fire behaviour, insulation, workability and circularity. They are editorial, not certificates.
Seven chapters follow. Fire and insulation claims name test families (Euroclass, ASTM E84, ISO 5660, KS F) rather than inventing a single safety number.
深く読む
Deep dive: 鋼
鋼 (Fe–C (±Mn, Si, Cr…)) is a family of grades whose density 7.85 g/cm³, heat band 1370–1530 °C, and fire letter A1 as construction steel.
Heat, fire and insulation
Conductivity note: ~50 W/m·K. Insulation score 8/100 is relative to 32 entries — metals lose, VIPs and aerogels win.
Fire letter in editorial use: A1 as construction steel. Do not equate A1 with “safe in a blaze” or E with “illegal”. Assemblies decide.
How it is made and used
Origin: bloomery c. 1800 BCE / Bessemer 1856, Anatolia → Sheffield. The process chapter follows feedstock → conversion → forming → finish → install.
Uses span construction to packaging. Pairings matter: Concrete.
Market and circularity
Producers below are landmarks, not an endorsement ranking. Prices are bands, not live quotes.
Circularity mark 64/100. Ask which scrap, which certificate, which year.
プロファイル
強度
88
耐熱
72
火災性能
84
断熱
8
加工性
80
循環性
64
七つの章
よくある質問
Is steel non-combustible?
As a metal it is Euroclass A1, but it loses yield in fire and usually needs protection for a rated duration.
鋼 vs iron?
鋼 is iron with controlled carbon (typically <2%) and alloys; cast iron has more carbon and a different solidification path.
Does steel insulate?
No. Thermal conductivity is tens of W/m·K. Insulation is a separate layer (mineral wool, boards, VIP).
Why does steel rust?
Iron oxidises in the presence of water and oxygen. Alloys, zinc, paint or concrete cover slow that.
Is stainless “stainless” forever?
No. Chlorides, crevices and wrong grades pit. 304 vs 316 is a chemistry choice, not a slogan.
Can steel be recycled endlessly?
Magnetically, yes as a family. Copper contamination and coatings constrain some high-spec loops.
What is AHSS?
Advanced high-strength steels (dual-phase, TRIP, martensitic) used to lighten car bodies while keeping crash performance.
Green steel — real or label?
Hydrogen-DRI and high-scrap EAF cut process CO₂. Certificates vary; ask which route and which year.
アイコン
Bessemer converter
United Kingdom · 1856–
Bessemer converter is a reference point in the public image of 鋼.
Damascus / Wootz
India / Levant · antiquity
Damascus / Wootz is a reference point in the public image of 鋼.
POSCO Gwangyang
South Korea · 1987–
POSCO Gwangyang is a reference point in the public image of 鋼.
Cor-Ten weathering
United States · 1933–
Cor-Ten weathering is a reference point in the public image of 鋼.
Dual-phase AHSS
Global auto · 1970s–
Dual-phase AHSS is a reference point in the public image of 鋼.
Tamahagane tatara
Japan · traditional
Tamahagane tatara is a reference point in the public image of 鋼.
Sheffield crucible
United Kingdom · 1740–
Sheffield crucible is a reference point in the public image of 鋼.
Blast furnace
Global · medieval–
Blast furnace is a reference point in the public image of 鋼.
アイコンのオンオフで、棒が選択内の首位に合わせて再スケールされる。
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対戦
同じ家族、違う点数 — 一戦を選ぶ。
近い素材
六軸で最も近い隣人 — 強度、耐熱、火災、断熱、加工性、循環性。