Ductile iron, Chinese standard:GB/T 1348-1998
Ductile iron cast a single test blocks of the mechanical properties and metallographic structure
Grades | Intensity of tensionσb≥/MPa | Yield strengthσ0.2≥/MPa | Elongationδ5≥(%) | HardnessHBS | The main metallographic structure |
QT400-18 | 400 | 250 | 18 | 130~180 | Ferrite |
QT400-15 | 400 | 250 | 15 | 130~180 | Ferrite |
QT450-10 | 450 | 310 | 10 | 160~210 | Ferrite |
QT500-7 | 500 | 320 | 7 | 170~230 | Ferrite+pearlite |
QT600-3 | 600 | 370 | 3 | 190~270 | Pearlite+ferrite |
QT700-2 | 700 | 420 | 2 | 225~305 | Pearlite |
QT800-2 | 800 | 480 | 2 | 245~335 | Pearlite or tempering |
QT900-2 | 900 | 600 | 2 | 280~360 | Bainite or tempered martensite |
Impact performance of V-notch test specimens of single block
Grades | Room temperature impact toughness (23±5℃)αK≥/(J/cm2) | Low temperature impact toughness (-20±2℃)αK≥/(J/cm2) | ||
The average of three samples | Few values | The average of three samples | Few values | |
QT400-18 | 14 | 11 | – | – |
QT400-18L | – | – | 12 | 9 |
Mechanical properties of ductile cast attached test block and metallographic structure
Grade | Casting wall thickness/mm | Intensity of tensionσb≥/MPa | Yield strengthσ0.2≥/MPa | Elongationδ5≥(%) | HardnessHBS | The main metallographic structure |
QT400-18A | >30~60>60~200 | 390370 | 250240 | 1812 | 130~180 | Ferrite |
QT400-15A | >30~60>60~200 | 390370 | 250240 | 1512 | 130~180 | Ferrite |
QT500-7A | >30~60>60~200 | 450420 | 300290 | 75 | 170~240 | Ferrite+pearlite |
QT600-3A | >30~60>60~200 | 600550 | 360340 | 31 | 180~270 | Pearlite+ferrite |
QT700-2A | >30~60>60~200 | 700650 | 400380 | 21 | 220~320 | Pearlite |
Impact strength of V-notch test blocks of ductile iron attached
Grade | Casting wall thickness/mm | Room temperature impact toughness (23±5℃)αK≥/(J/cm2) | Low temperature impact toughness (-20±2℃)αK≥/(J/cm2) | ||
The average of three samples | Few values | The average of three samples | Few values | ||
QT400-18A | >30~60>60~200 | 1412 | 119 | — | — |
QT400-18AL | >30~60>60~120 | — | — | 1210 | 97 |
Hardness grades of ductile iron, hardness range and microstructure
Hardness grades | HardnessHBS | The main metallographic structure | Mechanical properties (reference value) | ||
Intensity of tensionσb≥/MPa | Yield strengthσ0.2≥/MPa | Elongationδ5≥(%) | |||
QT-H330 | 280~360 | Bainite or tempered martensite | 900 | 600 | 2 |
QT-H300 | 245~335 | Pearlite or tempering | 800 | 480 | 2 |
QT-H265 | 225~305 | Pearlite | 700 | 420 | 2 |
QT-H230 | 190~270 | Pearlite+ferrite | 600 | 370 | 3 |
QT-H200 | 170~230 | Ferrite+pearlite | 500 | 320 | 7 |
QT-H185 | 160~210 | Ferrite | 450 | 310 | 10 |
QT-H155 | 130~180 | Ferrite | 400 | 250 | 15 |
QT-H150 | 130~180 | Ferrite | 400 | 250 | 15 |
ISO International standard:ISO 1083:1987
Ductile iron grades and mechanical properties of single test blocks,metallographic structure
Grade | Intensity of tensionσb≥/Mpa | Intensity of tensionσ0.2≥/Mpa | Elongationδ≥(%) | HardnessHBS | The main metallographic structure |
900-2 | 900 | 600 | 2 | 280~360 | Bainite or tempered martensite |
800-2 | 800 | 480 | 2 | 245-335 | Pearlite or tempering |
700-2 | 700 | 420 | 2 | 225~305 | Pearlite |
600-3 | 600 | 370 | 3 | 190~270 | Pearlite+ferrite |
500-7 | 500 | 320 | 7 | 170~230 | Ferrite+pearlite |
450-10 | 450 | 320 | 10 | 160~210 | Ferrite+pearlite |
400-15 | 400 | 250 | 15 | 130~180 | Ferrite |
400-18 | 400 | 250 | 18 | 130~180 | Ferrite |
350-22 | 350 | 220 | 22 | ≤150 | Ferrite |