Engineering Materials
Cobalt in steel

Improves cutting ability and reduce hardenability
Refines grain size and produces less tendency to carburisation, improve corrosion and heat resistant proper ties
Gives ductility, toughness, tensile strength and anti corrosion property
Improves wear resistance, cutting ability and toughness

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Engineering Materials
In a hardening process, the hypo-eutectoid steel is

Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
Heated below or closes to the lower critical temperature and then cooled slowly
Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium

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