mcq2-17

What is the purpose of the hardening process?

• Increase ductility
• Develop high hardness and wear-resistance properties
• Reduce toughness
• Lower the melting point

At what temperature is steel typically heated during hardening?

• Below freezing point
• 30-500°C above the upper critical temperature
• Room temperature
• 1000°C and above

How is the soaking time determined during hardening?

• Fixed at 1 hour
• 10 minutes per 1 cm of steel thickness
• Varies depending on the day of the week
• Not required

Which cooling medium is commonly used for plain carbon steels during quenching?

• Air
• Oil
• Brine solution
• Water

What effect does hardening have on steel's mechanical properties?

• Reduces strength and ductility
• Increases toughness
• Lowers hardness
• Affects all properties except hardness