Size Range： Thickness 2MM-120MM

Tolerance： According to GB/T 1591-2018

Length：As request

Certificate: Mill Certificate

Grade

C

Si

Mn

P

S

Nb

V

Ti

Cr

Ni

Cu

N

Mo

Als

Q345B

≤0.20

≤0.50

≤1.70

≤0.035

≤0.035

≤0.07

≤0.15

≤0.20

≤0.30

≤0.50

≤0.30

≤0.012

≤0.10

/

Q345C

≤0.20

≤0.50

≤1.70

≤0.035

≤0.030

≤0.07

≤0.15

≤0.20

≤0.30

≤0.50

≤0.30

≤0.012

≤0.10

≥0.015

Q345D

≤0.18

≤0.50

≤1.70

≤0.035

≤0.025

≤0.025

≤0.15

≤0.20

≤0.30

≤0.50

≤0.30

≤0.012

≤0.10

≥0.015

Mechanical Properties:

Grade	Yeild Strength    min Mpa			Tensile Strength	Elongation	Impact Test
	T in mm			Mpa
	≤16	＞16 ≤30	＞30			℃	Impact/J
							≥
Q345B	345	325	295	470-630	≥20	20	34
Q345C	345	325	295	470-630	≥21	0	34
Q345D	345	325	295	470-630	≥21	-20	34

Q345C is a kind of low-alloy high-strength structural steel: (corresponding to the old grades before 88 years: 16Mn, 12MnV, 14MnNb, 16MnRe, 18Nb five grades merged) Q is the first letter of the Chinese pinyin of the Chinese character "yield", indicating the strength of yield 345 is the specific value of yield strength: 345MPa The C at the back is the quality grade symbol of the steel of this strength level, generally divided into A, B, C, D, E and other levels (the higher the level, the higher the level) Note: The five grades A, B, C, D, E do not correspond to the previous five steel grades, but the quality grades. The main difference is that the requirements for impact energy are different: Q345-A: Impact power is not required Q345-B: Requirements for impact energy at room temperature Q345-C: requires 0℃ impact energy Q345-D: requires an impact energy of -20℃ Q345-E: requires -40℃ impact energy It can be seen that the following steel grades can be used at low temperatures