BF–BOF
Iron ore + coke→Blast furnace→Basic oxygen steelmaking→Casting
Follow steel from melt to finished product.
Steelmaking establishes the melt. Rolling, coating and finishing establish different product forms; these are separate choices.
Two steelmaking routes
EAF
Scrap / DRI / pig iron→Electric arc furnace→Casting
EAF does not mean every furnace uses only scrap. Neither route alone establishes the finished grade.
AISI · Steel Production · worldsteel · The steelmaking process
Rolling and finishing branch from the substrate.
| Stage | Resulting distinction | Continue reading |
|---|---|---|
| Hot rolling | HRC; pickling and oiling then produce HRPO. Removing scale does not add cold reduction. | HRC and HRPO |
| Cold reduction / annealing | CRC; grade and delivery condition govern the relevant properties. | CRC |
| Coating | EGI uses an electrolytic route; GI uses hot dipping; GA adds alloying heat treatment after dipping. Hot-rolled substrates can also be coated. | EGI, GI and GA |
| Paint system | A prepainted product joins its substrate, metallic coating where present, pretreatment and organic paint layers. | Prepainted steel |
| Other material families | Stainless and electrical steel are identified by their own composition/property families, not by a surface treatment on ordinary CRC. | STS · Electrical steel |
Hyundai Steel · Cold-rolled steel — PO / CR / GI / GA / EG · POSCO International · Steel products — Cold-rolled / Coated / Electrical / Stainless · Nippon Steel · Proposal of New Functional Prepainted Steel Sheets Utilizing the Color Tone of the Undercoat Film