Page 634 - Automotive Engineering Powertrain Chassis System and Vehicle Body

CHAP TER 1 8. 2 Materials for consideration and use in automotive body structures

Continuous
Mould: formation of liquid steel feed
a solid shell

Initial solidification
front
Secondary cooling:
continued solidification

Final solidification
front

Bottom of the liquid pool:
end of solidification Continuous withdrawal
at constant speed

Oxy-gas cut-off

The principle of continuous casting

Ladle liquid steel

Tundish

Mould

Product
transfer
Secondary
cooling
Withdrawal
Straightening Oxy-gas cut-off
Layout of a curved mould type continuous slab caster.
Fig. 18.2-4 Continuous casting showing solidification and extraction processes. 3

the length of the cycle being less than 10 minutes means correct allocation of material to the less demanding jobs
that recrystallization and grain growth are not as com- and a reasonable degree of rework to tools, the CAPL
plete as for the batch annealed (BA) product. This has products are now in regular use. The rapid annealing
been observed in the press shop where for lower grades capability has also been used to tailor the properties of
of forming steels (DCO 2/3) the ‘as received’ properties high strength steels by control of composition and
have not matched the BA ductility levels. However, by temperature/time cycle with the result that bake-hardening

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