1. STEEL MANUFACTURING

2. IRON AND STEEL MANUFACTURE TECHNOLOGY RELATED TO THE PRODUCTION OF IRON AND ITS ALLOYS, PARTICULARLY THOSE CONTAINING A SMALL PERCENTAGE OF CARBON. THE DIFFERENCES BETWEEN THE VARIOUS TYPES OF IRON AND STEEL ARE SOMETIMES CONFUSING BECAUSE OF THE NOMENCLATURE USED. STEEL IN GENERAL IS AN ALLOY OF IRON AND CARBON, OFTEN WITH AN ADMIXTURE OF OTHER ELEMENTS. SOME ALLOYS THAT ARE COMMERCIALLY CALLED IRONS CONTAIN MORE CARBON THAN COMMERCIAL STEELS. OPEN-HEARTH IRON AND WROUGHT IRON CONTAIN ONLY A FEW HUNDREDTHS OF 1 PERCENT OF CARBON. STEELS OF VARIOUS TYPES CONTAIN FROM 0.04 PERCENT TO 2.25 PERCENT OF CARBON. CAST IRON, MALLEABLE CAST IRON, AND PIG IRON CONTAIN AMOUNTS OF CARBON VARYING FROM 2 TO 4 PERCENT. A 2 SPECIAL FORM OF MALLEABLE IRON, CONTAINING VIRTUALLY NO CARBON, IS KNOWN AS WHITE-HEART MALLEABLE IRON. A SPECIAL GROUP OF IRON ALLOYS, KNOWN AS FERROALLOYS, IS USED IN THE 3. THE EXACT DATE AT WHICH PEOPLE DISCOVERED THE TECHNIQUE OF SMELTING IRON ORE TO PRODUCE USABLE METAL IS NOT KNOWN. THE EARLIEST IRON IMPLEMENTS DISCOVERED BY ARCHAEOLOGISTS IN EGYPT DATE FROM ABOUT 3000 BC, AND IRON ORNAMENTS WERE USED EVEN EARLIER; THE COMPARATIVELY ADVANCED TECHNIQUE OF HARDENING IRON WEAPONS BY HEAT TREATMENT WAS KNOWN TO THE GREEKS ABOUT 1000 BC. THE ALLOYS PRODUCED BY EARLY IRON WORKERS, AND, INDEED, ALL THE IRON ALLOYS MADE UNTIL ABOUT THE 14TH CENTURY AD, WOULD BE CLASSIFIED TODAY AS WROUGHT IRON. THEY WERE MADE BY HEATING A MASS OF IRON ORE AND CHARCOAL IN A FORGE OR FURNACE HAVING A FORCED DRAFT. UNDER THIS TREATMENT THE ORE WAS REDUCED TO THE SPONGE OF METALLIC IRON FILLED WITH A SLAG COMPOSED OF METALLIC IMPURITIES AND CHARCOAL ASH. THIS SPONGE OF IRON WAS REMOVED FROM THE FURNACE WHILE STILL INCANDESCENT AND BEATEN WITH HEAVY SLEDGES TO DRIVE OUT THE SLAG AND TO WELD AND CONSOLIDATE THE IRON. THE IRON PRODUCED UNDER THESE CONDITIONS USUALLY CONTAINED ABOUT 3 PERCENT OF SLAG PARTICLES AND 0.1 PERCENT OF OTHER IMPURITIES. OCCASIONALLY THIS TECHNIQUE OF IRONMAKING PRODUCED, BY ACCIDENT, A TRUE STEEL RATHER THAN WROUGHT IRON. IRONWORKERS LEARNED TO MAKE STEEL BY HEATING WROUGHT IRON AND 3 CHARCOAL IN CLAY BOXES FOR A PERIOD OF SEVERAL DAYS. BY THIS PROCESS THE IRON ABSORBED ENOUGH CARBON TO BECOME A TRUE STEEL. 4. A fte r the 1 4 th ce ntu ry th e fu rn a ce s u sed in sm e ltin g w e re in cre ased in size , a nd in cre a se d d raft w a s used to fo rce the co m b u stio n ga se s th ro ug h the cha rge , th e m ixtu re of ra w m a te ria ls. In th ese la rg e r fu rn a ce s, the iro n o re in the up pe r pa rt of the fu rna ce w a s first re du ce d to m e ta llic iron a nd th en to o k on m o re ca rb on as a re su lt of th e ga se s fo rce d th roug h it b y the b la st. T he p ro d uct of the se fu rn a ce s w a s p ig iron , a n a llo y th at m e lts a t a lo w e r te m pe ra tu re tha n stee l o r w ro ug h t iro n. P ig iro n (so ca lled b e ca u se it w a s u sua lly ca st in stub by, rou nd ingo ts kn o w n as p ig s) w a s the n fu rth e r refin ed to m a ke stee l. M o d e rn ste e lm akin g e m p lo ys b la st fu rn a ce s tha t a re m e re ly refin e m e n ts of th e fu rna ce s u se d b y the o ld iron w o rke rs. T he p ro ce ss of refin ing m o lte n iro n w ith b la sts of a ir w a s a cco m p lish ed b y th e B ritish in ve n to r S ir H en ry B e sse m e r w ho d e ve lop ed th e B e sse m e r fu rna ce , o r co n ve rte r, in 1 85 5. S in ce th e 1 96 0 s, se ve ra l so -ca lled m in im ills h a ve be en p ro du cing stee l fro m scra p m e ta l in e le ctric fu rna ce s. S u ch m ills a re an im p o rtan t co m po ne nt of to ta l U .S . stee l p ro du ctio n . T he g ia nt ste e l m ills re m a in e ssen tia l fo r th e p ro du ction of ste e l fro m iron o re . 4 5. 5 6. WHAT IS STEEL ? In the beginning, there was iron...Then came cast iron......and finally steel 7. GENERAL ISSUES ABOUT STEEL Steel has been called the worlds most useful and inexpensive metal.In recent decades, steel manufacturers have been forced to take a much closer look at what their processes have been doing to the fragile environment around them. 8. WHAT IS STEEL USED FOR - I The structure of the Pyramid of the Louvre, canned food, oil platforms, catalytic converters, paper clips, mounts for electronic chips...are all made of steel.1.In the construction of bridges or buildings...2.In the automobile sector... 9. WHAT IS STEEL USED FOR-II 3.5.For everyday uses: cans,pots,containers,etc...In communications...6.In energy...4.At the heart of food preservation...7.In health... 10. HOW IS STEEL MADE-II 11. HOW IS STEEL MADE-III 12. STEEL PRODUCTS Semi-finished products(continuous cast steel)Finished products (rolled steel) 13. STEEL MAKING PLANTElectric Arc FurnaceLadle FurnaceContinuous Casting Machine 14. HOW IS STEEL MADE-I 15. STEELMAKING MADEscrap SIMPLE Steel Iron Ore Coal/Coke Natural gas Oil ElectricityBlast FurnaceOxygen SteelmakingSecondary SteelmakingSteel scrap Coal/Coke Electricity Natural Gas Electric Arc SteelmakingContinuous Casting 16. 19