Volume 15 - Casting Part 10 pptx

Table 1 Effects, levels, and sources of some trace elements in gray ironElement Trace level, % inoculants, scrap contaminated with aluminum components white metal bearing shells, delib

Between two points in the same part of the mold; not affected by parting plane or core

>25 >1 0.38 ± 0.002 mm/mm over 25 mm 0.015 ± 0.002 in./in over 1 in

Flatness tolerance, as-cast

Greatest

Within 0.020 Each additional mm (in.) (b) 0.003 mm/mm 0.003 in./in

Across parting plane; A-type dimension plus below

Projected area of casting,

affected by moving part,

Precis Met.,

Table 4 Typical tolerance relations for shell mold steel castings

Dimension

Across

mm in ± mm ± in ± mm

0.010 0.010 0.015 0.015 0.020 0.020 0.020 0.025 0.025 0.030

0.030 0.030 0.035 0.035 0.040 0.040 0.040 0.045 0.045

508 20 1.52 0.060 1.27 0.050

• Geometric dimensioning and tolerancing

Characteristic Symbols.

Table 5 Symbols used in geometric dimensioning and tolerancing

Type of feature Type of tolerance Characteristic

Total

Design of Ferrous Castings,

Aluminum Casting Technology,

Mod Cast.,

Precis Met.,

Casting Design Handbook,

Mod Met., Geo-Metrics II,

Composition

Type of Iron Total carbon,

%

Silicon, %

Sulfur levels

Table 1 Effects, levels, and sources of some trace elements in gray iron

Element Trace

level, %

inoculants, scrap contaminated with aluminum components

white metal bearing shells, deliberate addition

bismuth-containing molds and core coatings

scrap

refined pig iron

scrap, some refined pig iron

binders, some ferroalloys, steel scrap

≤ Free-cutting brasses, mold and core

coatings, deliberate addition

refined pig iron, deliberate addition

vitreous enamels and paints, deliberate addition

Vanadium ≤0.08 Forms carbides; promotes pearlite Steel scrap; some pig irons

Solidification

Graphite Morphology

Matrix Structure

α

Phase Tensile strength,

Table 2 Hardness ranges for various combinations of gray iron microstructures

110-140 200-260 300-450 260-350 350-550 Austenite + graphite 140-160

Section Sensitivity

Table 3 Minimum recommended section sizes for unalloyed gray irons

0.28

0.48 0.48 0.47

0.90 0.90 0.90

1.29 1.29

Plate 114 mm (4 in.) × 305 × 305 mm (12 × 12 in.)

32.7 1.29

Hochwertiges Gusseisen,

Trans AFS,

Trans AFS,

Principles of Metal Casting,

Metallographic Etching,

Mod Cast.,

Mod Cast.,

Typical Microstructures of Cast Metals, Gray and Ductile Iron Castings Handbook, Physical and Engineering Properties of Cast Iron,

Cast Met Res J.,

Trans AFS, Trans AFS,

Melting

Charge constituent

-7 to 12

-10 to 20 -10 to 15 -15 to 25 -15 to 25 +Trace -10 to 20 -2 to 5 -2 to 5 -5 to 10 Sulfur +40 to 60

Inoculation

Table 5 Compositions of ferrosilicon inoculants for gray cast iron

Performance category

of inoculant

Alloying

Trans AFS,

Proceedings of AFS-CMI Conference,

Proceedings of AFS-CMI Conference,

Proceedings of AFS-CMI Conference,

Trans AFS,

Proceedings of AFS-CMI Conference,

AIME Electric Furnace Conference Proceedings,

Trans AFS,

Foundry Trade J.,

Foundry Trade J.,

Trans AFS,

Heat Treating ASM Handbook.

Mechanical Properties

Table 7 As-cast mechanical properties of standard gray iron test bars

Tensile strength Torsional

shear strength

Compressive strength

Reversed bending fatigue limit

Transverse load

on test bar Class

Material

2-4 8-15 5-20 20-100 100-500

4

5

Aluminum 0.4

Properties and Selection: Irons, Steels, and Performance Alloys ASM Handbook.

High-Physical Properties

Table 8 Physical properties of gray iron as a function of tensile strength

Tensile strength Density (a) Thermal conductivity at indicated temperature (b) , W/m·K

Mpa ksi g/cm 3 lb/in 3 100 °C (212 °F) 300 °C (572 °F) 500 °C (932 °F)

μΩ

0.80 0.78 0.76 0.73 0.70 0.67

Brake drums and clutch plates for moderate service where high carbon is desirable to minimize heat checking

Cylinder blocks, heads, liners, flywheels, pistons, clutch plates

Truck cylinder blocks and heads, heavy flywheels, differential carriers

Brake drums and clutch plates for heavy-duty service that require heat resistance and high strength

Truck and tractor cylinder blocks and heads, heavy flywheels, tractor transmission cases, differential carriers, heavy gear boxes

Extraheavy-duty brake drums

Alloyed automotive engine camshafts

Diesel engine castings, liners, cylinders, and pistons; heavy-duty parts for general industry Valve bodies, paper mill dryer rollers, chemical process equipment, pressure vessel castings

Stoker and firebox parts, grate bars, process furnace parts, ingot molds, glass molds, caustic pots, metal melting pots

Automobile, truck, appliance, and machinery castings in quantity

Valve guides, insecticide pumps, flood gates, piston ring bands

Seawater valve and pump bodies, pump section belts

Fertilizer applicator parts, pump impellers, pump casings, plug valves

Caustic pump casings, valves, pump impellers

Turbocharger housings, pumps and liners, stove tops, steam piston valve rings, caustic pumps and valves

Range tops

Glass rolls and molds, machine tools, gages, optical parts requiring minimal expansion and good damping qualities, solder rails and pots

6 Valves

Iron Castings Handbook,

Metal Progress: Materials & Processing Databook,

Hochwertiges Gusseisen,

Trans AFS,

Trans AFS, Principles of Metal Casting,

Metallographic Etching,

Mod Cast.,

Mod Cast.,

Typical Microstructures of Cast Metals, Gray and Ductile Iron Castings Handbook, Physical and Engineering Properties of Cast Iron,

Cast Met Res J.,

Trans AFS, Trans AFS,

Foundry Trade J.,

Trans AFS,

Mod Cast., The Gray Iron Castings Handbook,

Trans AFS,

Proceedings of AFS-CMI Conference,

Proceedings of AFS-CMI Conference,

Proceedings of AFS-CMI Conference,

Trans AFS,

Proceedings of AFS-CMI Conference,

AIME Electric Furnace Conference Proceedings,

Trans AFS, Foundry Trade J.,

Foundry Trade J.,

Trans AFS, Iron Castings Handbook,

Metal Progress: Materials & Processing Databook,

Trans AFS, The Structure of Cast Iron,

Trans AFS,

Physical Chemistry of Ferrous Melting,

J Iron Steel Inst.,

et al., International Atlas of Casting Defects, Trans AFS,

Mechanism of Graphite Formation in Iron-Silicon-Carbon Alloys,

Grade

0.03 max

Table 1 Typical minor element contents of raw materials for ductile iron

Raw Material

<0.01 0.01

Sc Sc

Met Prog., Gray, Ductile and Malleable Iron Castings Current Capabilities,

Magnesium Treatment

Inoculation (Ref 4)

Ductile Iron Molten Metal Processing,

Modern Inoculating Practices for Gray and Ductile Iron,

Solidification and Feeding (Risering)

M

M M

M M

Br Foundryman,

Br Foundryman,

Foundry Trade J Int.,

Giesserei-Prax.,

Table 2 Ductile iron property requirements of various national and international standards

Impact energy Tensile strength 0.2% offset

J ft · lbf J ft · lbf

Hardness, HB

Pearlite or tempered Pearlite

Pearlite + ferrite Ferrite + pearlite Ferrite

Ferrite

Ferrite Ferrite + pearlite Ferrite + pearlite Pearlite

DQ&T (c) Martensite

Table 3 Some tentative specifications for austempered ductile iron

Tensile strength

(min)

0.2% offset yield strength (min) Grade

Elongation (min), %

269-321 302-363 363-444 388-477

250-310 280-340 330-390

300-310 345-355 1200/1 1200 174 940 136 1 390-400

Engineering Data on Nodular Cast Irons-SI Units,

Properties and Selection: Irons, Steels, and High-Performance Alloys ASM Handbook.

Trans AFS,

Trans AFS,

Trans ASM,

Single-Stage Treatment.

Selection of Annealing Treatment.

Table 4 Examples of alloying combinations used to increase the hardenability of ductile iron

Alloying elements used, %

1 1.1 1.2 1.5 2.0 3.4 2.0 0.9 1.5 0.25 63 2.5

•

Flame and induction hardening

hardness, HRC

Surface hardness after treatment, HRC

0.06

Remelt Hardening.

The Heat Treatment of SG Cast Iron,

Austempered Ductile Iron: Your Means to Improved Performance, Productivity and Cost, Austempered Ductile Iron: Your Means to Improved Performance, Productivity and Cost,

Properties and Selection: Irons, Steels, and High-Performance Alloys ASM Handbook.

Table 5 Some mechanical properties expected in ductile iron grades covered by UK standard B52789

Tensile

strength

Yield strength

Yield strength in compression

Shear strength

Torsional strength

Poisson's ratio, ν

Hardness, HB

MPa ksi MPa

26

28

29

30

32

36

41

44

46

41

44 900/2 900 131 710 103 2 719 104 810 117 810 117 172 24.9 67.1 9.7 0.275 >259 190 46 317 46

Table 6 Some physical properties expected of ductile iron grades covered by UK specification BS2789

Specific heat capacity, 20-700 °C (68-1290

°C (68-750 °F), 10 -6 /K

0.500 0.510 0.530

0.540 0.540 0.540

>0.540

>0.540

Table 7 Tensile design stresses for three nodular irons at elevated temperatures

Temperature Maximum tensile

design stress Grade Structure

0.52 × (0.1% offset yield strength)

0.45 × (0.1% offset yield strength)

300 570 147 21

0.45 × (0.1% offset yield strength)

Table 8 Growth and scaling of ductile irons in air

Exposure temperature

Growth Grade

°C °F

Exposure time, years

mm/mm in./in.

0.00 8.77 12.61

13.71 0.00 21.93 29.60 33.44 0.00 5.48 9.87 9.87 0.00 16.45 26.31 32.34 0.00 6.03 10.42 9.87 0.00 17.54 24.12 21.3 0.000 0.000 27.96

Table 9 Stress required to produce specific creep strain or rupture in ductile iron

225 (32.5) 195 (28) 154

(22.5)

136 (20) 114 (16.5)

Engineering Data on Nodular Cast Irons-SI Units,

Austempered Ductile Iron: Your Means to Improved Performance, Productivity and Cost,

Gray Iron News,

Corrosion ASM Handbook Metals Handbook.

Ductile Iron II Engineering Design, Properties, Applications,

γ

Trans AFS,

Trans AFS,

Trans AFS,

Table 10 Mechanical properties of weld joints in ASTM A 536, grade 60/45/10, ductile iron

Tensile strength 0.2% offset

yield strength Specimen Type of shielding

Elongation,

%

Reduction in area, %

81

80

86

80 Transverse (a) CO 2 467 68 300 43.5

Properties and Selection: Irons, Steels, and High-Performance Alloys ASM Handbook

Foundryman,

Weld J., Machining Data Handbook,

VDI Z., VDI Z.,

Ductile Iron II Engineering Design, Properties, Applications,

Konstruieren and Giessen,

Met Prog., Gray, Ductile and Malleable Iron Castings Current Capabilities,

Ductile Iron Molten Metal Processing,

Modern Inoculating Practices for Gray and Ductile Iron,

Br Foundryman,

Br Foundryman,

Foundry Trade

J Int.,

Giesserei-Prax., Engineering Data on Nodular Cast Irons-SI Units,

Trans AFS,

Trans AFS,

Trans ASM, The Heat Treatment of SG Cast Iron,

Heat Treating, Metals Handbook, Austempered Ductile Iron: Your Means to Improved Performance, Productivity and Cost,

Austempered Ductile Iron: Your Means to Improved Performance, Productivity and Cost,

Gray Iron News,

VDI Z., VDI Z., Konstruieren and Giessen,

Giesserei-Prax.,

T T

T T

Nodularity =

Giesserei-Prax.,

Trans AFS,

Br Foundryman,

Trans AFS,

Trans AFS,

Trans AFS,

Trans AFS, Trans AFS,

Giesserei-Prax.,

Trans AFS,

Mod Cast, Trans AFS,

AFS Cast Met Res J.,

Trans AFS,

Trans AFS,

Trans AFS, Trans AFS,

The Physical Metallurgy of Cast Iron,

Trans AFS,

Giesserei-Prax.,

Br Foundryman,

Giesserei-Prax.,

Table 2 Typical mechanical properties of CG iron

Tensile strength 0.2% offset yield

strength

Modulus of elasticity Iron matrix

Elongation,

%

GPa ksi × 10 3

130-179 Pearlitic 405-620 59-90 315-425 45-63 1-2 127-165 18.5-24 207-269

•

•

Table 3 Properties of CG as a function of nodularity

Tensile strength Nodularity, %

Table 4 Effect of heat treatment on tensile properties of CG iron

Tensile Yield

strength strength MPa ksi MPa ksi

170

156 Normalized 90% pearlite 490 71 420 61 2.5 229

Br Foundryman,

Trans AFS, Trans AFS,

Trans AFS,

AFS Cast Met Res J.,

Iron Castings Handbook, The Properties of Cast Iron up to 500 °C,

Trans AFS,

Russ Cast Prod., Spravotchnik po Tshugunomu Litiu (Cast Iron Handbook),

Trans AFS,

BCIRA J.,

N

Br Foundryman,

BCIRA J., Giessereiforschung,

Trans.AFS,

Trans AFS, Trans AFS,

Table 5 Thermal conductivities of FG, CG, and SG irons at various temperatures

Br Foundryman,

Trans AFS,

Corrosion ASM Handbook Metals Handbook.

Br Foundryman,

Trans AFS, BCIRA J.,

Trans.AFS, Russ Cast Prod.,

Trans AFS,

Trans AFS,

Br Foundryman,

Trans AFS,

Trans AFS, Trans AFS,

Trans AFS, Trans AFS,

Giesserei-Prax.,

Trans AFS,

Mod Cast, Trans AFS,

AFS Cast Met Res J.,

Trans AFS,

Trans

Trans AFS, Trans AFS,

The Physical Metallurgy of Cast Iron,

Trans.AFS,

Trans AFS, Trans AFS,

Trans AFS,

Russ Cast Prod.,

Trans AFS,

Giessereikalender 1981,

Giesserei,

Table 1 Composition and mechanical requirements of abrasion-resistant cast irons per ASTM A 532

Class Type Designation

1.0 max (a) 1.0 max (a)

1.0 max 1.0 max (b) 0.5-1.0 (c) 1.0-3.0 (c) 2.3-3.5 (c) 1.5 max (c) 1.0-2.0 (c) III A 25% Cr 2.3-3.0 0.5-1.5 1.0 max 1.5 max 23.0-28.0 1.5 max (c)

Class Type Designation

Sand cast, min

Chill cast, min

Hardened, min

Softened, max

III A 25% Cr 450 600 400 8 200

•

•

Melting Practice

Composition Control

Pouring Practices

Molds, Patterns, and Casting Design

Shakeout Practices

Heat Treatment

Machining

Applications

Special Nickel-Chromium White Iron Alloys

Classes of High-Chromium Irons

Microstructures

Selecting Compositions to Obtain Desired Structures

Table 2 Minimum alloy content to avoid pearlite in mold-cooled castings for indicated effective section size (plate thickness or radius of rounds)

ASTM A 532 class Cr (a) , % C (a) , %

25 mm (1 in.)

50 mm (2 in.)

1.5 Mo + 1.0 (Ni + Cu)

2.5 Mo + 1.0 (Ni + Cu) 1.0 Mo + 1.0 (Ni + Cu) 2.0 Mo + 1.0 (Ni + Cu) 1.0 Mo

3.0 1.0 Mo 1.5 Mo 1.5 Mo + 1.0 (Ni + Cu)

Table 3 Minimum alloy content to avoid pearlite in heat treatment for indicated effective section size (plate thickness or radius of rounds)

ASTM A 532 class Cr (a) , % C (a) , %

50 mm (2 in.)

125 mm

2.0 Mo + 1.0 (Ni + Cu) 2.5 Mo + 1.2 (Ni + Cu) (b) 2.0 Mo + 0.5 (Ni + Cu) 2.0 Mo + 1.2 (Ni + Cu) (b) 1.5 Mo + 0.5 (Ni + Cu)

Melting Practice

Pouring Practices

Molds, Patterns, and Casting Design

Shakeout Practices

Heat Treatment

γ

Machining

Applications

Special High-Chromium Iron Alloys

•

•

•

σ

Abrasion Resistant Castings for Handling Coal,

Engineering Properties and Applications of Ni-Hard,

Foundry Trade J.,

Trans AFS,