- 1 -IfG - Institut für Gießereitechnik
- 1 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Dr.-Ing. Wolfram Stets; Dr.-Ing. Herbert Löblich;
Prof. Dr.-Ing. Peter Schumacher; Dr. Gert Gassner
Solution strengthened ferritic spheroidal graphite cast iron according DIN EN 1563:
2012-03- Production, properties and application
- 2 -IfG - Institut für Gießereitechnik
- 2 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Economic efficiency
Product quality
Process stability
Materials properties
Qualified employees
Environmental protection and health & safety
…..Single – source consultancy and research
IfG – Institut für GießereitechnikThe branch institute of the German foundry industry
- 3 -IfG - Institut für Gießereitechnik
- 3 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
The revised standard DIN EN 1563 includes three new cast iron grades:
EN-GJS-450-18
EN-GJS-500-14
EN-GJS-600-10
EN-GJS- 450-18 500-14 600-10
Rm [N/mm2]
min.450 500 600
Rp0,2 [N/mm2]
min.350 (310) 400 (320) 470 (370)
A [%] min. 18 (10) 14 (7) 10 (3)
Material
Values in brackets: comparable grades of the conventional GJS
Initial situation
- 4 -IfG - Institut für Gießereitechnik
- 4 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Si contents between 3 and 4,3 % cause a solution strengthened 100 % ferrite microstructure with high
mechanical properties
The pearlite generating elements
Mn, Cu, Sn
in the conventional alloys determine the pearlite / ferrite ratio and the mechanical properties.
EN GJS-600-3
EN GJS-600-10
- 5 -IfG - Institut für Gießereitechnik
- 5 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Contents of the project
• Static Mechanical properties in dependence on the Silicon content
• Influence of carbide and pearlite generating elements (Mn, Cr, V) on the static mechanical properties
• Cast technological properties of high Silicon ductile iron
• Influence of inoculation on microstructure in dependence on the wall thickness
• Investigation of the machinability of high Silicon ductile iron
- 6 -IfG - Institut für Gießereitechnik
- 6 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Production of several cast samples for the materials investigation
Radial sample
Y2 sample
Y4 sample
Wedge samples
Samples for shrinkage testing
1) Static mechanical properties
- 7 -IfG - Institut für Gießereitechnik
- 7 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Rm and Rp0,2 pass through a maximum in dependence on the Si content
Massenprozent Silicium
Rm
[Mpa
]
Y-2Y-4
2 3 4 5 60
100200
300400500600700
4,3%
Si
Separate cast Y-samples
[MP
a]
Mass% Silicon
- 8 -IfG - Institut für Gießereitechnik
- 8 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Massenprozent Silicium
Bru
chde
hnun
g [%
]Y-2Y-4
2 3 4 5 60
5
10
15
20
25
30
In the neighbourhood of 4,3 % Si the elongation is decrasing
4,3%
Si
Separate cast Y-samples
Mass% Silicon
Elo
ngat
ion
[%]
- 9 -IfG - Institut für Gießereitechnik
- 9 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Mass% Silicon
HB
Har
dnes
s
Continous course of the hardness in dependence on Si content
- 10 -IfG - Institut für Gießereitechnik
- 10 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
[MP
a]
No influence of the added elements on the tensile strength
2) Influence of carbide and pearlite generating elements on the static mechanical properties.
Added elementsNon
- 11 -IfG - Institut für Gießereitechnik
- 11 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
4,3%
Si
[MP
a]
No influence of the added elements on the yield strength
Added elementsNon
- 12 -IfG - Institut für Gießereitechnik
- 12 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
The elongation is reduced with 0,6 % Cr
[%]
Non Added elements
Elo
ngat
ion
[%]
- 13 -IfG - Institut für Gießereitechnik
- 13 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Y2-Probe: 4,03% Si; 3,01 %C; 1,0 % Mn
Rm: 581 MPa; Rp0,2: 486 MPa; A: 19,8 %
Y2-Probe: 3,99 % Si; 3,01 %C; 0,63 % Cr
Rm: 649 MPa; Rp0,2: 506 MPa; A: 14,3 %
ca. 25% pearlite
- 14 -IfG - Institut für Gießereitechnik
- 14 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
3) Cast technological properties of high Silicon ductile iron
Downsprue with
turbulences
Filter
Collecting bassin with scale
• Dross generating behaviour
Filling of the bassin in dependence on the time
- 15 -IfG - Institut für Gießereitechnik
- 15 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
• Mold filling behaviour
Cast harp sample
Degree of filling in dependence on the Si content and pouring temperature
No strong influence of Si
- 16 -IfG - Institut für Gießereitechnik
- 16 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
4) Influence of inoculation on microstructure in dependence on the wall thickness
Wall thickness (radial sample)
inoculantC
onte
nt o
f gra
phite
sh
ape
V +
VI [
%]
Different inoculants generate a wide range of microstructure
- 17 -IfG - Institut für Gießereitechnik
- 17 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Con
tent
of g
raph
ite
shap
e V
+ V
I [%
]
Wall thickness (radial sample)
Inoculant 2
Not only the inoculant determines the microstructure but also the Si content.
- 18 -IfG - Institut für Gießereitechnik
- 18 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Schematic correlation between inoculation technique, wall thickness and microstructure
Rising Si content
Inoculation good
Inoculation poor
Different inoculants
Wall thickness [mm]
Con
tent
of g
raph
ite
shap
e V
+ V
I [%
]
- 19 -IfG - Institut für Gießereitechnik
- 19 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Graphite shape deviation comparable to Chunky graphite
- 20 -IfG - Institut für Gießereitechnik
- 20 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
5) Investigation of the machinability of high Silicon ductile iron
Longitudinal turning of cylindrical castings (diameter 120 mm)- tool life at cutting speed 240 m/min
Tool life 50 – 60 % longer
- 21 -IfG - Institut für Gießereitechnik
- 21 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
GJS-600-3GJS-600-10
min
Mittelwert
max
476
271288
210
135 165
0
50
100
150
200
250
300
350
400
450
500
Frei
fläch
enve
rsch
leis
s in
µm
minMittelwertmax
Flank wear at the machining of planet carriers (300 kg), materials GJS-600-3 and GJS-600-10.
- 22 -IfG - Institut für Gießereitechnik
- 22 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Comparison of hardness and microstructure of GJS-600-3 with GJS-600-10
Hardness course
- 23 -IfG - Institut für Gießereitechnik
- 23 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Microstructure of GJS-600-3
etched
- 24 -IfG - Institut für Gießereitechnik
- 24 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Microstructure of GJS-600-10
etched
- 25 -IfG - Institut für Gießereitechnik
- 25 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
6) Summarization
• The new grades of GJS give a optimized combination of strength and thoughness (static loading).
• The worse influence of carbide generating elements is suppressed by the high Si content.
• The castability of the Si alloyed GJS is not worse than the conventional alloys
• The inoculation technology must be adapted to the new grades
• The high Si contents enhance the probability of graphite deviations
• The cyclic mechanical properties of the Si alloyed GJS grades are higher
- 26 -IfG - Institut für Gießereitechnik
- 26 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Das vorgestellte IGF-Vorhaben der Forschungsvereinigung Gießereitechnik e.V. FVG, Sohnstraße 70, 40237 Düsseldorf wurde
über die AiF Allianz Industrieforschung im Rahmen des Programms zur Förderung der industriellen Gemeinschaftsforschung und –entwicklung
(IGF) vom BMWi Bundesministerium für Wirtschaft und Technologie aufgrund eines Beschlusses des Deutschen Bundestages gefördert.
- 27 -IfG - Institut für Gießereitechnik
- 27 -CastTech, Krefeld, 09.11.2012 – High Silicon Ductile Iron
Thank you !