HOT ROLLING MILL OF NARROW STEEL STRIP
[EIRI/DPR/3656](J.C.: 6156)
INTRODUCTION
Mechanical working of a metal is simply plastic deformation performed to change dimensions, properties and surface condition by means of mechanical pressure. Mechanical working may be either hot working or cold working depending on temperature and strain rate such that recovery processes take place simultaneously with the deformation. Plastic deformation above recrystallisation temperature, but below the melting or burning point, is hot work. Some metals, such as lead and tin, have a low recrystalline range and can be hot worked at room temperature, but most commercial metals require some heating. Plastic deformation below the recrystallisation temperature is cold work. Although normal room temperatures are ordinarily used for cold working of steel, temperatures up to the recrystallisation range are sometimes used. In cold working, recrystallisation processes are not effective. It is, therefore, important to realise that the distinction between hot working and cold working does not depend upon any arbitary temperature, but also on the recrystallisation temperature, of deformation.
Hot Working
Hot working is the initial step in the mechanical working of most metals and alloys. Hot working combines the working and annealing processes by deforming metal above the recrystallisation temperature at which new grains are formed. Since most metals and alloys have relatively high recrystallisation temperatures, they must be worked at high temperatures. Each metal of course, has a characteristic hot-working temperature range over which hot working may be performed. The upper limit of working temperature depends on metal composition, prior deformation and impurities within the metal. Obviously, the upper limit for working must be somewhat below the melting or burning point. The finishing temperature, however, is usually just above the minimum recrystallisation temperature at which reheating is desired before further hot working.
In addition to mere change of shape, hot working has profound effects on metal characteristics or properties. These are listed under Table 6.1. The changes in structure from hot working improve mechanical properties such as ductility, toughness, elongation percentage, reduction of area percentage and resistance to shock and vibration.
COST ESTIMATION
Plant Capacity 16.67 MT/Day
Land & Building (20,000 sq.mt.) Rs. 41.00 Lac
Plant & Machinery Rs. 1.15 Cr
Working Capital for 3 Months Rs. 3.59 Cr
Total Capital Investment Rs. 5.37 Cr
Rate of Return 37%
Break Even Point 47%
CONTENTS
INTRODUCTION
USES AND APPLICATIONS
PROPERTIES
PRESENT MINI STEEL UNIT
B.I.S. SPECIFICATIONS
RAW MATERIAL REQUIREMENT
MANUFACTURING PROCESS
BLOCK DIAGRAM FOR ROLLING STRUCTURAL SHAPES
ABOUT THE TOOL ROOM
PLANT LAYOUT
SUPPLIERS OF PLANT & MACHINERIES
APPENDIX – A:
01. PLANT ECONOMICS
02. LAND & BUILDING
03. PLANT AND MACHINERY
04. OTHER FIXED ASSESTS
05. FIXED CAPITAL
06. RAW MATERIAL
07. SALARY AND WAGES
08. UTILITIES AND OVERHEADS
09. TOTAL WORKING CAPITAL
10. TOTAL CAPITAL INVESTMENT
11. COST OF PRODUCTION
12. TURN OVER/ANNUM
13. BREAK EVEN POINT
14. RESOURCES FOR FINANCE
15. INSTALMENT PAYABLE IN 5 YEARS
16. DEPRECIATION CHART FOR 5 YEARS
17. PROFIT ANALYSIS FOR 5 YEARS
18. PROJECTED BALANCE SHEET FOR (5 YEARS)