3. HOT ROLLING SHOP 4. COLD ROLLING SHOP

Transcription

1 STAINLESS STEEL MANUFACTURING PROCESS 1. INTRODUCTION 2. MELTING SHOP 3. HOT ROLLING SHOP 4. COLD ROLLING SHOP

2 1. INTRODUCTION CONVERT RAW MATERIALS IN FINAL PRODUCTS (COILS AND SHEETS) RAW MATERIALS YARDS

3 STAGE 1: Melting Shop Raw Materials Slabs

4 STAGE 2: Hot Rolling Mill Slab Black Coil

5 STAGE 3: Cold Rolling Mill Black Coil Final Product (Coils and Sheets)

6 2. MELTING SHOP 2.1. RAW MATERIALS 2.2. ELECTRIC ARC FURNACE 2.3. A.O.D. CONVERTER 2.4. CONTINUOUS CASTING 2.5. GROUNDING.

7 2. MELTING SHOP MELTING SHOP Raw Materials Electric Arc Furnace A.O.D. Continuous Converter Casting Slab Grounding MELTING SHOP PROCESS FLOW

8 2.1. RAW MATERIALS TYPES SCRAPS FERROALLOYS AUXILIARIES.

9 2.1. RAW MATERIALS Scrap Ferroalloys

10 2.2. ELECTRIC ARC FURNACE DESCRIPTION PROCESO ELECTRODES BRICK ARCH CHARGE BASKET MELTING TILTING SAMPLES

11 2.2. ELECTRIC FURNACE Charge Basket tilting in EAF

12 2.2. Electric Furnace Tilting

13 2.3. A.O.D. CONVERTER Argon-Oxygen-Decarburation

14 2.3. A.O.D. CONVERTER PROCESS DECARBURATION REDUCTION SLAGGING OFF DESULFURIZATION REFINING

15 2.3. A.O.D. CONVERTER DECARBURATION OXYGEN AND INERT GAS (partial pressure) 2C + O 2 2CO CO + 1/2O 2 CO 2 REDUCTION ON DECARBURATION IS PRODUCED: 2M+O 2 2MO REDUCER MIX: Si + CaO MO + Si SiO 2 +M SLAGGING OFF + CaO Slag former

16 2.3. A.O.D. CONVERTER Slagging off

17 2.3. A.O.D. CONVERTER DESULFURIZATION DESULPHURIZING MIX: CaO + Si SM + CaO SCa + OM OM + Si SiO 2 +M REFINING SEVERAL CHEMICAL COMPOSITION CONTROLS DURING THE PROCESS

18 2.4. CONTINUOUS CASTING DESCRIPTION Ladle Tundish Casting mold Cooling, roller table Torch cutting

19 2.4. CONTINUOUS CASTING Tundish

20 2.4. CONTINUOUS CASTING Torch cutting

21 2.5. GROUNDING REMOVE SUPERFICIAL DEFECTS ABRASIVE WHEELS

22 3. HOT ROLLING MILL 3.1. PREHEATING FURNACE 3.2. ROUGHING MILL 3.3. FINISHING MILL 3.4. DOWN COILER 3.5. HOT PLATE SHOP

23 3. HOT ROLLING MILL HOT ROLLING MILL Hot Plate Shop Preheating Roughing Steckel Hot rolled Furnace Mill Mill coil

24 3.1. PREHEATING FURNACE ROLLING TEMPERATURE: ºC HOLDING TIME: 200 minutes

25 3.2. ROUGHING MILL From 200 mm to 25 mm Reversing Mill (Several roll pass) Exit temperature: 1050ºC

26 3.2. FINISHING MILL COILS FROM 2 TO 10 mm STECKEL MILL REVERSING FURNACE COILERS (temperature holding) EXIT TEMPERATURE: ºC

27 3.2. FINISHING MILL Steckel Mill

28 3.3. DOWN COILER BLACK COIL OBTAINING TEMPERATURE: 800 ºC

29 3.4. HOT PLATE SHOP PLATES: SHEETS GAUGE FROM 10 TO 50 mm HOT PLATE SHOP PROCESS ANNEALING PICKLING CUTTING INSPECTION AND Y PACKING

30 4. COLD ROLLING MILL 4.1. HOT ANNEALING AND PICKLING 4.2. COLD ROLLING 4.3. FINAL ANNEALING ANG PICKLING

31 4. COLD ROLLING MILL Hot Annealing and Pickling Line Bell Furnac e Final Annealing and Pickling Lines Bright Annealing Lines Push Pickling Line 2B Finish Coils BA Finish Coils Packing Packing Annealed and Pickled Coil. Finish Nº 1 Slitter Line Shearing Line 2B/BA Finish Coils 2B/BA Finish Sheets Sendzimir Mill Polishing Line Polish nº3,4, etc., coils End Inspection Packing and Expedition Circle Cutting Press

32 4.1. HOT ANNEALING AND PICKLING HOT ANNEALING AND PICKLING OBJECT Structure regeneration (recrystallisation) Characteristics recovering

33 4.1. HOT ANNEALING AND PICKLING PROCESS DIFFERENCES BETWEEN: Austenitics 1050 ºC Short holding times Ferritics and Martensitics 800º C Long holding times CONTINUOUS LINES / BELL LINES FURNACES OXIDIZING ATMOSPHERE FURNACES

34 4.1. HOT ANNEALING AND PICKLING PICKLING To remove hot rolling and annealing scale. PROCESS Blasting Acid tanks Intermediate rinsings Final rinsing and drying

35 4.2. COLD ROLLING Hot Annealing and Pickling Line Bell Furnac e Final Annealing and Pickling Lines Bright Annealing Lines Push Pickling Line 2B Finish Coils BA Finish Coils Packing Packing Annealed and Pickled Coil. Finish Nº 1 Slitter Line Shearing Line 2B/BA Finish Coils 2B/BA Finish Sheets Sendzimir Mill Polishing Line Polish nº3,4, etc., coils End Inspection Packing and Expedition Circle Cutting Press

36 4.2. COLD ROLLING OBTAIN COILS GAUGES BETWEEN 0,25 AND 6 mm ROLLING ON SENDZIMIR MILLS Coilers 20-rolls stand

37 4.2. COLD ROLLING

38 4.3. FINAL ANNEALING AND PICKLING FINAL ANNEALING OBJECT: Structure regeneration (recrystallisation) Characteristics recovering PROCESS: Treatment temperature Austenitics: 1050 ºC Ferritics and martensitics: 800º C Holding time neccesary to recrystallisation Quenching to avoid carbide precipitation and embrittlement

39 4.3. FINAL ANNEALING AND PICKLING PICKLING Remove annealing scale PROCESS Molten salts bath Acid Tanks Intermediate rinsings Final rinsing and dryng

40 4.3. BRIGHT ANNEALING BA LINES Inert atmosphere N 2 /H 2 Pickling isn t needed Vertical furnaces Muffle Electric Mixed

41 SKP PROCESS Two-roll mill. Target Flatness Brightness Remove fluence (elastic plastic flow transition region)

42 CUTTING LINES Slitter lines Cut to length shearing lines Circle cutting press

43 PACKING