R05321805-steel-making

Set No. 1

Code No: R05321805

III B.Tech II Semester Supplimentary Examinations, Aug/Sep 2008 STEEL MAKING (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) (b) (c) (d)

Distinguish between acid iron and basic iron Explain why acid iron is also called haematite iron or sweedish iron. Explain what is Thomas iron. What is steel scrap? Explain about various types of steel scraps used in steel making. [5+3+3+5]

2. Explain (a) Molecular theory and (b) Ionic theory of refininng of slags in steel making process. [16] 3. With the help of a neat sketch describe the process of Basic Bessermer process steel making with respect to Construction, refractories, melting practice and refining of steel making. [16] 4. Explain with the help of a neat sketch steel making by Rotor oxygen process in detail with reference to vessel design, refractory lining, oxygen lance and operation. [16] 5. (a) Compare and contrast Open Hearth Furnace and Electric Arc Furnace. (b) Describe about the various types of scrap charged in Electric Arc Furnace. [8+8] 6. Describe the following with figures : (a) Teeming Ladle (b) Stopper assembly (c) Ladle lining

[6+6+4]

7. (a) Write about the formation of zone of columnar crystals. (b) Describe scab, lappiness, splash and double skin.

[8+8]

8. Write short notes on the following used in continuous casting of steel making : (a) Molten steel handling system (b) Tundish (c) Mould

[4+6+6] ⋆⋆⋆⋆⋆ 1 of 1

Set No. 2

Code No: R05321805

III B.Tech II Semester Supplimentary Examinations, Aug/Sep 2008 STEEL MAKING (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Why the steel produced by cementation process is called blister steel? Explain. (b) Distinguish between single-shear steel and double-shear steel. (c) Describe the traditional steel making process which was in practice untill the end of Nineteenth century. What are the limitations of the process. [5+4+7] 2. Write short notes about the following: (a) Ladle degassing (b) Cementation process (c) Triplex process.

[5+5+6]

3. (a) Give the typical composition of hot metal used in basic Bessemer process and discuss the sequence of reactions in basic Bessemer process. (b) Discuss the modern developments in the open-hearth steel making practice. [9+7] 4. (a) What are the basic differences between top and bottom blown converter processes? What are the advantages of the combined blowing processes? Explain. (b) Consider the momentum flow rate as a parameter of oxygen jet characterstics, compare the performance of 3 hole nozzle and 4 hole nozzle for refining in BOF process. [10+6] 5. (a) What are the steps in Electric Arc Furnace ? (b) Describe melting and refining in Electric Arc Furnace process with reactions. [6+10] 6. Write short notes on : (a) Mould Materials (b) Bottom plate (c) Hot tops (d) Mold life and mold preparation 7. With the help of neat sketches explain the following : (a) Principle components of ladle furnace 1 of 2

[3+3+5+5]

Set No. 2

Code No: R05321805 (b) Describe SKF furnace

[6+10]

8. (a) What are the advantages of producing blooms, slabs etc by primary mills ? (b) What are the advantages of continuous casting of steel ? (c) What is the principle of continuous casting of steel ? What are the equipment used for continuous casting of steel ? [4+4+8] ⋆⋆⋆⋆⋆

2 of 2

Set No. 3

Code No: R05321805

III B.Tech II Semester Supplimentary Examinations, Aug/Sep 2008 STEEL MAKING (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Explain the deleterious effects of sulphur, phosphorus, and manganese on steels. (b) Explain the term gunning/fettling with reference to refractory lining. [10+6] 2. (a) Write short notes on ionic theory of slags. (b) Explain the essential conditions required for effective desulphurization and dephosphorization in steel making processes. [8+8] 3. (a) With reference to open hearth process, discuss the following i. Design of ports and port ends ii. Function of air and gas uptakes downtakes and slag pockets. (b) Explain carbon boil and lime boil periods in open hearth process.

[10+6]

4. What is L.D process? With the help of a neat sketch explain the steel making by L D process. What are the advantages and limitations of this process over other methods of steel making. [16] 5. Describe the process of steel making in Electric Arc Furnace.

[16]

6. Discuss about various types of ingot moulds used for casting of steel.

[16]

7. (a) Write about the formation of zone of columnar crystals. (b) Describe scab, lappiness, splash and double skin.

[8+8]

8. (a) Compare ESR and VAR processes. (b) Explain the process of producing stainless steel. ⋆⋆⋆⋆⋆

1 of 1

[8+8]

Set No. 4

Code No: R05321805

III B.Tech II Semester Supplimentary Examinations, Aug/Sep 2008 STEEL MAKING (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) What are the various fluxes used in steel making process? Explain about them. Also give theoritical analysis of various fluxes. (b) What are the main raw materials required for steel making? Briefly explain about them. [8+8] 2. What do you mean by deoxidation? What are the main requirements of a deoxidiser? Mention four simple and complex deoxidisers and explain about them in detail. [16] 3. (a) Explain the nitrogen problem in Bessemer steel making practice giving reasons and methods to minimise/eliminate such problems. (b) How the use of liquid fuels, in place of gaseous fuels, simplifies design and construction of open hearth furnace. [8+8] 4. (a) Give a detailed list of parameters in a blowing process in LD converter. Explain about them. (b) Briefly explain the AJAX process of steel making.

[10+6]

5. Write short notes on : (a) Electrodes (b) Transformers and power ratings and consumption. (c) Electrode support assembly

[5+5+6]

6. (a) What is teeming of steel ? (b) What factors affect teeming temperature of steel ? (c) What are the functions of a teeming ladle ?

[4+6+6]

7. (a) Define killed steel, semi-killed steel and rimmed steel. (b) What are the uses of killed steel ? (c) Explain the mechanism of solidification of killed steel with a diagram. [4+4+8] 8. (a) What are the advantages of producing blooms, slabs etc by primary mills ? (b) What are the advantages of continuous casting of steel ? (c) What is the principle of continuous casting of steel ? What are the equipment used for continuous casting of steel ? [4+4+8] ⋆⋆⋆⋆⋆ 1 of 1