Casting Material: Spheroidal Graphite Cast Iron 400-18LT
Ductile Iron EN-GJS-400-18 is defined in standard EN1563: 2011 Founding. Spheroidal graphite cast irons, There are three grades: EN-GJS-400-18 LT, EN-GJS-400-18 RT and EN-GJS-400-18. LT means low temperature; RT for room temperature.
China grade is QT400-18LT.
It’s mainly used in wind turbine and wind power station, include hub, gear box, bed and base. It’s a low temperature impact resistant ductile cast iron.
Generally, this grade material will be made by sand casting include green sand and resin sand casting method. Casting Quality Industrial provide to 20ton castings.
Wind Power Casting, EN-GJS-400-18LT
Chemical Composition for 400-18LT
To get the good property, the chemistry is very important in casting process. The chemical composition shall be left to the discretion of the manufacturer
Recommend chemistry:
| C | Si | Mn | P | S | Mg | RE |
| 3.5-3.8 | 2.0-2.3 | 0.3 | 0.04 | 0.03 | 0.025-0.030 | 0.02-0.04 |
Heat Treatment for 400-18LT
Heat Treatment: Anneal is necessary to improve the mechanical property.
Heat to 900-950C, hold 2-5 hours, 600c in furnace, cool in air.
Annealing Process for EN-GJS-400-18LT
The Mechanical Property for 400-18LT
| Specimen from Separately sample | Specimen from Cast-On sample | Tensile Strength Rm N/mm2 min | 0.2Proff Stress Rp0.2 N/MM2 Min | Elongation A % min | Minimum Impact Resistance Value (inJ) | |||||
| Symbol | Number | Symbol | Number | At Room Temperature (23+/5) C | At -20+/-2 C | |||||
| EN-GJS-400-18 | EN-JS1020 | EN-GJS-400-18U | EN-JS1062 | 400 | 250 | 18 | Average | Individual | Average | Individual |
| EN-GJS-400-18LT | EN-JS1025 | EN-GJS-400-18U-LT | EN-JS1049 | 400 | 240 | 18 | – | – | 12 | 9 |
| EN-GJS-400-18RT | EN-JS1024 | EN-GJS-400-18U-RT | EN-JS1059 | 400 | 250 | 18 | 14 | 11 | – | – |
Microstructures example for ductile iron 400-18LT
 100X Surface Microstructure, unetched, EN-GJS-400-18 |  100X Core Microstructure unetched, EN-GJS-400-18 |
 400X Anneal unetched , EN-GJS-400-18 |  400X Anneal, etched , EN-GJS-400-18 |
Comparison:
| EN/EU | USA | DIN | JIS | FRANCE | UK | EN | Sweden | Norway | ISO |
| EN-GJS-400-18LT | 60-40-18 | 0.7043 GGG40.3 | FCD400-18L | 400-18L20 | 400/18L20 | EN-JS1025 | 17-02 | SJK-400.3 | 400-18 400-18LT |
Mechanical properties
ReH Minimum yield strength / Mindestwert der oberen Streckgrenze / Limite d elasticite minimale
Rm Tensile strength / Zugfestigkeit / Resistance a la traction
A Minimum elongation / Mindestwert der Bruchdehnung / Allongement minimal
J Notch impact test / Kerbschlagbiegeversuch / Essai de flexion par choc