Homework cap 2
What is the difference (regarding alloying elements percentage) between stainless
steel and low alloyed steel?
Correct answer :
Low alloy steel: up to approximately 5% of alloying elements Stainless steel: >5%, mainly chromium and
nickel as an alloying element
Explain the difference between Hot and Cold rolled steel.
Correct answer :
Cold rolling
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T < 721°C (<recrystallization)
Heavier equipment than hot rolling
Thin products possibilities e.g. < 4mm
Hard and smooth surfaces, the piece strength increment by strain work hardening
Higher quality of surface
More expensive than hot rolling due to stronger rollers and the need for heat stress releasing
treatment (annealing) which is done by moderate re-heating
No mill scale created
Hot rolling
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High temperatures >721°C
Low adherent mill scale created