EN-GJS-700-2 (High-Strength Pearlitic Ductile Iron)

Description

EN-GJS-700-2 per EN 1563. Fully pearlitic matrix (achieved through Cu/Sn pearlite-promoting additions and controlled cooling) gives Rm>=700 MPa -- one step below the top GJS-800-2 grade, with slightly better castability and machinability. Standard for heavy-duty industrial gears, medium-to-large diesel engine crankshafts, and structural castings requiring high strength as a cost-effective alternative to forged steel.

Key Properties — As Cast (pearlitic)

Rm (Tensile Strength)

700 – 850

MPa

Re / Rp0.2 (Yield)

420

MPa

A₅ (Elongation)

≥ 2.0

Hardness

225 – 305

E (Young's Modulus)

175

GPa

Density

7.10

g/cm³

Main Designations (8)

Standard Body	Designation	Country / Region	Note
EN	EN-GJS-700-2	EU
ISO	ISO 1083 Grade 700-2	International
ASTM	A536 Grade 100-70-03 (nearest)	USA
JIS	FCD700-2	Japan
GOST	VCh70 (VCh70)	Russia
UNS	F34700 (nearest)	USA (UNS)
GB	QT700-2	China
JUS	Duktilni.700	Yugoslavia/BiH	Sfero-liv perlitni 700-2; JUS B.H3.010

Standards (8)

#	Standard Body	Designation	Country / Region	Note
1	EN	EN-GJS-700-2	EU	—
2	ISO	ISO 1083 Grade 700-2	International	—
3	ASTM	A536 Grade 100-70-03 (nearest)	USA	—
4	JIS	FCD700-2	Japan	—
5	GOST	VCh70 (VCh70)	Russia	—
6	UNS	F34700 (nearest)	USA (UNS)	—
7	GB	QT700-2	China	—
8	JUS	Duktilni.700	Yugoslavia/BiH	Sfero-liv perlitni 700-2; JUS B.H3.010

All values in wt.%

Carbon (total)

3.4000 – 3.7000

Silicon

2.1000 – 2.6000

Manganese

0.3000 – 0.7000

Copper (pearlite promoter)

0.3000 – 0.7000

Magnesium

0.0300 – 0.0600

Element	Symbol	Min %	Max %	Typical %
Carbon (total)	C	3.4000	3.7000	3.5500
Silicon	Si	2.1000	2.6000	2.3500
Manganese	Mn	0.3000	0.7000	0.5000
Copper (pearlite promoter)	Cu	0.3000	0.7000	0.5000
Magnesium	Mg	0.0300	0.0600	0.0450

Mechanical Properties

Condition	Code	Rm min MPa	Rm max MPa	Re min MPa	Re max MPa	A₅ min %	Z %	KV J	HB min	HB max	HRC min	HRC max	E GPa
As Cast (pearlitic)	+F	700	850	420	—	2.0	—	—	225	305	—	—	175.0

Physical Properties

Density

7.100

g/cm³

Melting Point

1130–1195

°C

Young's Modulus

175.0

GPa

Poisson's Ratio

0.275

—

Thermal Conductivity

29.0

W/m·K

Thermal Expansion

12.20

×10⁻⁶ /K

Specific Heat

460

J/kg·K

Electrical Resistivity

0.6600

µΩ·m

Magnetic

Yes

Heat Treatment

Stress Relieving

Temperature:500°C – 560°C

Medium:Furnace

Duration:2-4 h

Cooling:<=30 C/h

Hardness After:+-5 HB

For precision machined components.

Surface Hardening (induction)

Temperature:850°C – 920°C

Medium:-

Duration:-

Cooling:Water spray

Hardness After:HRC 50-58

Common on crankshaft journals and gear teeth.

Normalising (optional, for property consistency)

Temperature:880°C – 920°C

Medium:Air cool

Duration:-

Cooling:Air cool

Hardness After:Uniform pearlite content

Improves consistency in castings with variable section thickness.

Machinability

Machinability Rating

relative to AISI B1112 = 100%

38.0%

Very Difficult

Turning Speed (HSS)

m/min

Turning Speed (Carbide)

128

m/min

Feed Rate (Turning)

0.140

mm/rev

Drilling Speed (HSS)

m/min

Milling Speed (Carbide)

130

m/min

Coolant	Dry or light air blast; flood for heavy cuts
Chip Formation	Short abrasive chips -- more difficult than GJS-600-3
Tool Material	Carbide K10 TiAlN; CBN for high-volume production
Surface Finish	Ra 0.8-3.2 um

More difficult than GJS-600-3. CBN recommended for production gear/crankshaft machining.

Applications

Heavy Gears

Industrial gearbox gears requiring strength above GJS-600-3 capability.

Crankshafts

Medium-to-large diesel engine crankshafts.

Structural Castings

High-strength structural castings as a forged-steel alternative.

Technical Notes

✅

GJS-700-2 vs GJS-600-3 vs GJS-800-2

GJS-600-3: A=3%, moderate strength, better machinability. GJS-700-2: A=2%, higher strength, between 600-3 and 800-2. GJS-800-2: A=2% (min), maximum standard GJS strength, most difficult to machine. GJS-700-2 offers a practical strength step-up from 600-3 while remaining somewhat easier to machine than the top 800-2 grade.