Ingot Cleanliness Improvements Using Sprue Extensions ...

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Ingot Cleanliness Improvements Using SprueExtensions Beyond The Mold Outlet

Ryan VanderMeulen

ArcelorMittal Coatesville

April 11, 2012

2

Steelton

Coatesville

Conshohocken

Burns Harbor Cleveland

Lackawanna

Hennepin

Columbus Coatings

Riverdale

Indiana Harbor

Steelmaking and processing facilities

Processing facilities

Research center

Research Center

Weirton

Georgetown

ArcelorMittal USA Locations

Newton

3

ArcelorMittal USAPlate Production Locations

Steelmaking, Rolling, Heat Treating:Burns Harbor, Coatesville

Rolling & Heat Treating:Conshohocken, Gary

Steelmaking:Indiana Harbor,Cleveland, Riverdale

CoatesvilleConshohocken

BurnsHarbor,Gary

ClevelandIndiana Harbor

Riverdale

4

Plate Mills Production Focus

• Burns Harbor– 160” – larger, TMCP, Q&T, precise weight

– 110” – commodity to 1”

– 160” @ Gary – commodity to 1.5”, Q&T

• Conshohocken– 110” - commodity, thin, Q&T

• Coatesville –– 140” - heavy, varied chemistries, Q&T

– 206” - very wide and heavy, Q&T

5

Production Focus

• EastClad, Flamecut, ConversionMost alloy and Q&TVery clean steelVery wide or heavy plateLight thickness plateSmall special orders

• WestControl rolledPrecise weightSpecial surface requirementsVery large ordersHeat Treated Commodity

6

ArcelorMittal USA OperationsCoatesville Steelmaking Process Plan

Ladle

Argon Stirring

Electrodes

Wire Feed

Argon Stirring

AutomaticAlloys

Ladle Furnace

Electric Arc Furnace

ContinuousCast Slabs

Ladle Degasser

BottomPoured Ingots

AutomaticAlloys

7

Ingot CastingCoatesville

• Bottom pouring

• Hot topping

• Argon shrouding

• Maximum sizeplate 50 tons (45 Mt)

8

Bottom Poured, Ingot Casting

Ladle

ArgonShroud

Argon Inlet

CenterRunner

RunnerBrick

MoltenSteel

Mold

CastingPowder

Hot Top

9

Products Produced From Ingots

• Thick plates, 3/1 reduction for PVQ; structural grades2/1; military 4/1

• Heavy plates over ~13.5 sTon

• Difficult chemistries– High sulfur free machining grades

– Tool steels

– Certain military grades

– Some unique customer requirements (prequalification)

• Grades covering wide thickness range with limitedproduction

10

High Strength Q&T Steels

• A514 family and T-1®

Steels, Hardwear®

• High strength orabrasion resistance

• Flatness requirements

1/2 commercial

• Fabrication guidelines

11

A514 Steels

• A514A - to 1-1/4” N-A-Xtra,National

• A514B * T-1A® to 1-1/4”

• A514E - to 6” ex-Armco

• A514F* T-1® to 2-1/2”

• A514H* T-1B® to 2”

• A514Q* T-1C® to 6” basis for gearrack grades

* PWHT cracking concerns

12

API Offshore Steels

• 2H42 and 50 (N)

• 2Y50 and 50T (QT)

• 2MT1 (CR, AC)

• 2Y60 (QT)

• Burns Harbor

– AC, N, QT

• Coatesville

– N, QT

– Special Chemistry (Pcm)

– Heavy plate, ingot

– RP 2Z prequalified Ingot to 3”

13

Pressure Vessel Steels

• Shipped to ASTM A20requirements

• Fabricators export theirvessels

• Plate export opportunities

• Most popular grades A516,A387 - 11/22, A353/553, Clad,A203E, A537, A299

14

A516

• C-Mn steels to 15” (380 mm) thick and 100,000pounds (45,000 kg) weight

• -50oC to +300oC temperature pressure vesselapplications, Grades 55, 60, 65 and 70

• Carbon equivalent controls and HIC - testing

• Available normalized or Q&T

• Similar behavior of A299 steels

15

A387

• Cr-Mo steels to 12” (305 mm) thick and 100,000pounds (45,000 kg) weight

• Grades 11 (1-1/4 Cr - 1/2 Mo) and 22 (2-1/4 Cr - 1Mo) most popular; other grades to 9% Cr

• Elevated temperature pressure vessel applications

• Temper embrittlement resistance

• Post weld heat treatment (stress relief)

• Available N&T or Q&T

16

Roll-Bonded Clad

• Composite of economical “Backing Steel” and high performancealloy

– examples: A516/304L, A387/410S, A36/C276

• Assembly of a “Clad Pack”

• Cost advantages

• Fabrication procedures - forming and welding

• Pressure vessels, FGD systems, pulp and paper equipmentSpacer bars

Nickel LayerBacking Steel

Alloy Inserts Parting Compound

17

Military Armor

• Navy Armor Steels - HY-80 & 100,HSLA-80 & 100 - surface shipsand submarines

• Army Armor Steels - moderateand high hardness grades - M-1tanks, other vehicles

• Require Q&T and Fineline®

• Special testing - first article,ballistic

• Plates from ingots usedparticularly in Carriers

18

AISI Alloy and Mold Steels

• Chemistry only grades

• Most popular 4140, 4142, 4130,

8620, 4340

• All vacuum degassed, some may

be Clean-Cut or Fineline

• Thermal cutting and quench

cracking concerns

• Used in variety of tooling

applications, including MTD steels

19

MTD® Steels

• Mold, tool and die pre-hardened steels for plasticinjection molds and holder blocks, 262-321HB*

• MTD #1 - N&T 4142 used to 6-1/2” thick

• MTD #2 - Q&T 4130 used to 12” thick

• MTD #3 - Q&T .30% carbon, Fineline quality to12” thick; ingot only for internal quality, BEUwhere possible

• MTD #4 - N&T 4150 used to 6-1/2” thick

• MTD #1, #2, #4 may be Clean-Cut quality

* MTD #1 and #4, to 3”: 241-320 over 3 - 6-1/2”

20

Free Machining Grades

• Higher sulfur levels for improved machinability

• Clean-Cut® 20 and 45, .06/.12 sulfur, twocarbon levels, calcium treated to 15” thick

• C1119 mod. and C1144 mod., .24/.33 and.20/.33 sulfur levels always ingot

• Clean-Cut® Alloy Steels, .02/.04 sulfur, calciumtreatment available in 4140, 4142, 4150, 8620,MTD #1, #2 and #4

21

Tool Steels

• Cold work tool steels - A2, 01, S7, S5, D2, A8 mod.

• Mostly ingot produced at Coatesville, some meltedoff-site– D2 ingot from outside source

– S5 can be strand cast

• Long processing cycles

• Produce full sized plates that customers can cut intobars

• Flatness tolerances are critical for cutting andmachining

22

Bridge Steels

• Industry push to use ASTMA709

• Grades 36 through 100 ksiyield

• Three zones for determiningCVN impact requirements,also fracture-critical membercriteria

• New HPS 50W/70W/100W

• Ingots used in thick, wide&/or long plates

23

Flame-Cut Products

• Oxygen-fuel or plasma cuttingof all grades, thicknesses andweights of plate we can roll

• Beveling of edge detail/weldpreparation to drawingspecifications

• Plates/parts can be pressflattened to meet tolerances

• Finished pieces used instructural and sub-assembly,forming, fabrication andmachining applications

24

Common Ingot Quality Issues

• Cracks

– Rate of Rise

– Mold Centering

• Hot Top Fins

– Board Fit in Molds

• End/Side Laminations

– Solidification

– Rolling

• Pipe/Burst/UT Failure

– Solidification

– Cooling

– Trapped Junk

25

Potential Sources of Trapped Junk

• Foreign debris including cardboard

• Damaged Refractory Brick

• Nalcosil

• Runner Sand

• Fluxes/Powders – most common HT2

26

Ladle Sand

• Prevents steel from escaping through the outlet

• Protects opening of ladle from damage

• Allows for better flow of steel

27

Refractory Brick

• Can be easily fractured or crack

• Uneven plates cause bricks to be misaligned

28

The‘Trap’

29

The ‘Trap’

Sprue Cap

14” Double MaleStraights

9” Slotted Outlet

30

Picture of Sprue

31

End of Sprue

32

Diagram of Sprue

Note: A, B, C, D, E are all ½”

13”

OUTLET

.5”0 2”1” 2.5” 6.5” 7” 13.5”

END A B C D E

Distance from the End to Outlet

1” 4” 6”

33

End Pieces

• Where most junk was found

• Not fully circular

C0082 C0086Melt No.-Position C0192-1 C0192-3

34

Definition of Junk

• All non-metallics

• Material on edge of piece extending deep into the surface

• For air bubbles, only parts that appeared to have been non-steel material

35

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

4.0%

0 2 4 6 8 10 12 14

Distance from End to Outlet (inches)

Per

cen

tIn

clu

sio

n

C0082

C0086

Trapped Inclusions for C0082/C0086

36

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

0 2 4 6 8 10 12 14

Distance from End to Outlet (inches)

Per

cen

tIn

clu

sio

n

C0192-1

C0192-3

Trapped Inclusions for C0192

37

Percent Inclusion by Piece

Piece C0082 C0086 C0192-1 C0192-3

A 3.8% 3.6% 13.3% 15.8%

B 1.2% 0.59% 9.8% 6.5%

C 0.17% 0.08% 3.9% 6.0%

D 0.17% 0% 2.8% 7.6%

E 0.12% 0% 0%

Total % Inclusion 0.42% 0.25% 3.3% 5.5%

38

Indication of Swirling Motion

C0086A

C0086B

C0192-1D

C0192-3D

39

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Middle % 6.7% 2.2% 27.3% 25.1%

Outer % 93.3% 97.8% 72.7% 74.9%

C0082 C0086 C0192-1 C0192-3

Location of JunkOutside

Middle

1.5”

1.06”50% ofArea

40

Flow Model

CenterRunner

Mold

Sprue

‘Trap’

41

Flow Video

42

Cost

• Refractory cost increase per ingot of ~3%.

• Worst-case yield loss of ~0.1%.

• Total cost increase under $1.00/ton.

• One trapped junk rejection = $5,000+ depending on size andgrade. Can be over $20,000 for large armor ingots.

43

Follow-Up Work

• Work with vendor to develop a standard “trap brick”

• Integrate trap usage into all special heats to start

• Make traps standard for all heats

44

Conclusion

• Demonstrated ‘Trap’ is capable of catching junk

• Minimal cost and yield loss

• Potential to produce cleaner ingots and reduce the number ofrejections

45

Questions?

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