Chemical properties GB standards

Materials come in different chemical compositions which generally increase with increase in material grades, with an exception of carbon which varies. Below is a table of chemical properties.

Chemical Properties

Materials

Grade

% of Mass fraction,based upon heat and product analyses

 

 

Carbon

Silicon

Chrome

Copper

Molybdenum

Nickel

Nitrogen

Aluminium

Manganese

 

 

max.

min.

max.

max.

max.

max.

max.

max.

max.

Q345

Grade A

≤0.20

≤0.50

0.3

0.3

0.1

0.5

0.012

0.015

≤1.70

Grade B

Grade C

Grade D

≤0.18

Grade E

Q390

Grade A

≤0.20

≤0.50

0.3

0.3

0.1

0.5

0.015

0.015

≤1.70

Grade B

Grade C

Grade D

Grade E

Q420

Grade A

≤0.20

≤0.50

0.3

0.3

0.2

0.8

0.015

0.015

≤1.70

Grade B

Grade C

Grade D

Grade E

Q460

Grade C

≤0.20

≤0.60

0.3

0.55

0.2

0.8

0.015

0.015

≤1.80

Grade D

Grade E

Q500

Grade C

≤0.18

≤0.60

0.6

0.55

0.2

0.8

0.015

0.015

≤1.80

Grade D

Grade E

Q550

Grade C

≤0.18

≤0.60

0.8

0.8

0.3

0.8

0.015

0.015

≤2.00

Grade D

Grade E

Q620

Grade C

≤0.18

≤0.60

1

0.8

0.3

0.8

0.015

0.015

≤2.00

Grade D

Grade E

Q690

Grade C

≤0.18

≤0.60

1

0.8

0.3

0.8

0.015

0.015

≤2.00

Grade D

Grade E

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