Q690 Steel, Q690C Q690D Q690E Chemical Composition, Mechanical Properties

Q690 steel and Q690M material is a Chinese GB standard high strength low alloy structural steel, and devides into 3 quality grades: Q690C, Q690D and Q690E, “Q” means Yield Strength, “690” refers to 690 Mpa, Tensile Strength is 770-940 Mpa, “M” is short for “TMCP” (Thermal Mechanical Control Processing), for data sheet and specification, please refer to the following tables.

Steel plates made from Q690 material has high yield strength and tensile strength and is widely used in coal mine machinery and engineering machinery, such as hydraulic support, port cranes, flatbed trucks and so on.

Q690 Steel Chemical Composition

The chemical compositon of Q690C, Q690D, Q690E are displayed in the following table.

Q690 Chemical Composition (%)

Steel Grade

Quality Grade

Q690

Q690C

≤ 0.18

≤ 0.60

≤ 2.00

≤0.030

≤ 0.11

≤ 0.12

≤ 0.20

≤ 1.00

≤ 0.80

≤ 0.015

≤ 0.30

≤ 0.004

≥ 0.015

Q690D

≤0.030

≤0.025

Q690E

≤0.025

≤0.020

Q690 Carbon Equivalent Value (CEV): ≤0.49% (including C, D, E; all diameter)

Q690 Steel Mechanical Properties

			Q690 Yield Strength (≥N/mm2); Thickness or Dia. d (mm)
Standard	Steel Grade	Quality	d≤16	16<d≤40	40<d≤63	63<d≤80
GB/T 1591 – 2008	Q690	C, D, E	690	670	660	640
GB/T 1591 – 2018	Q690M	C, D, E	690	680	670	650

			Q690 Tensile Strength (N/mm2); d (mm)			Elongation
Standard	Steel Grade	Quality	d≤40	40<d≤63	63<d≤80	%
GB/T 1591 – 2008	Q690	C, D, E	770-940	750-920	730-900	≥14
GB/T 1591 – 2018	Q690M	C, D, E	770-940	750-920	730-900	≥14

1 Mpa= 1N/mm2

Q690M: “M” means TMCP (Thermal Mechanical Control Processing)

Welding crack sensitivity index (Pcm): ≤0.25% (Only for bars)

Charpy Impact Test of Q690 Material

Charpy Impact Test (V) – Test temperature and impact absorbed energy
Grade	Quality Grade	Test Temp. (℃)	Thickness	Absorbed Energy (KV2/J)
Q690 steel	Q690C	0	12mm-150mm	≥55
	Q690D	-20		≥47
	Q690E	-40		≥31
Impact test to take longitudinal samples.

Alloy Steel Structural Steel