The Chinese cast iron material grades were named by "HT" for gray cast iron, and "QT" as the ductile cast iron. The followings are their detailed grades, and related physical properties.As for the comparison table for Chinese material grades with the equal / equivalent grades in other countries, such as USA, UK, ISO, Japan, Italy, Spain, Austria and Germany etc., please refer to the article "Cast Iron Grades" made by Dandong Foundry.
Gray Cast Iron Grades in China
|
Grade |
Tensile Strength |
Hardness grade |
Hardness |
Relevant miscrostructure |
|
HT100 |
≥ 100 |
H145 |
≤170 |
ferrite |
|
HT150 |
≥ 150 |
H175 |
150~200 |
ferrite + pearlite |
|
HT200 |
≥ 200 |
H195 |
170~220 |
pearlite |
|
HT250 |
≥ 250 |
H215 |
190~240 |
pearlite |
|
HT300 |
≥ 300 |
H235 |
210~260 |
pearlite (inoculated cast iron) |
|
HT350 |
≥ 350 |
H255 |
230~280 |
pearlite (inoculated cast iron) |
Ductile Cast Iron Grades in China
|
Grade |
Tensile strength |
Yield strength |
Elongation |
Hardness |
Main microstructure |
|
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 + perlite |
|
QT600-3 |
600 |
370 |
3 |
190~270 |
perlite + ferrite |
|
QT700-2 |
700 |
420 |
2 |
225~305 |
perlite |
|
QT800-2 |
800 |
480 |
2 |
245~335 |
perlite or tempered structure |
|
QT900-2 |
900 |
600 |
2 |
280~360 |
Bainite or tempered martensite |