Building Materials, Third Edition

p2w  — QUU

The important reasons for alloy additions are:

1. To increase the hardenability of steel. The steel in this group are usually heat treated by
   quenching and tempering, for it is only this way that the added expanse of the alloys can
   be justified through the better combination of properties that is obtained.


2. To strengthen the steel when it is to be used without special heat treatment. The steels
   that fall in this category are designed specifically for constructional purposes.


3. To confer some special property such as machinability, corrosion resistance wear resistance,
   etc.

iˆi‚gsƒiƒ

1. (a) Name the ores required for making steel.
   (b) What is pig iron? Describe how it is manufactured from iron ore.
   (c) Describe briefly the manufacture of steel by open hearth process.


2. (a) State the differences between mild steel, wrought iron, cast iron and cast steel.
   (b) Give the properties and uses of stainless steel and high carbon steel.
   (c) What are the different methods of castings? State their advantages and disadvantages?


3. What is the effect of carbon, sulphur, phosphorus and silicon on
   (a) Steel (b) Cast iron (c) Wrought iron


4. (a) Specify some important uses of cast iron, wrought iron and mild steel.
   (b) What are the factors controlling composition and quality of steel?
   (c) What is alloy? Describe the properties and uses of some of the steel alloys.


5. (a) What is meant by cold short and red short irons?
   (b) What are the effects of different types of impurities in iron on its physical and mechanical
   properties?
   (c) Briefly describe the defects of cast iron.


6. What type of steel would you recommend in the following cases
   (a) Reinforcement in prestressed concrete and cement concrete
   (b) Cables of suspension bridge (c) Bridge girder
   (d) Spring (e) Hammer


7. Write short notes on the following:
   (a) Puddling (b) Red shortness
   (c)Grey cast iron (d) Bessemer pig iron


8. State the carbon contents and uses of the following metals:
   (a) Pig iron (b) Cast iron
   (c)Wrought iron (d) Low-carbon steel


9. (a) Describe in detail about the reinforcing steel used in reinforced cement concrete.
   (b) Describe in detail testing of steel sections.
   (c)Write a note on rolled steel sections.


10. (a) Defferentiate between mild steel rods and HYSD Bars.
    (b) Illustrate different market forms of rolled steel sections.


11. (a) Enumerate the properties of hard steel and mild steel.
    (b) Describe the properties and uses of high tensile steel.


12. Describe breefly corrosion of steel and measures adopted for its prevention.