Q690 Steel, Q690C Q690D Q690E Chemical Composition, Mechanical Properties

q690 steel plate, steel flat, steel sheet

Q690 steel or 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 GradeQuality GradeCSiMnPSNbVTiCrNiCuNMoBAl
Q690Q690C≤ 0.18≤ 0.60≤ 2.00≤0.030≤0.030≤ 0.11≤ 0.12≤ 0.20≤ 1.00≤ 0.80≤ 0.80≤ 0.015≤ 0.30≤ 0.004≥ 0.015

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)
StandardSteel GradeQualityd≤1616<d≤4040<d≤6363<d≤80
GB/T 1591 – 2008Q690C, D, E690670660640
GB/T 1591 – 2018Q690MC, D, E690680670650
Q690 Tensile Strength (N/mm2); d (mm)Elongation
StandardSteel GradeQualityd≤4040<d≤6363<d≤80%
GB/T 1591 – 2008Q690C, D, E770-940750-920730-900≥14
GB/T 1591 – 2018Q690MC, D, E770-940750-920730-900≥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
GradeQuality GradeTest Temp. (℃)ThicknessAbsorbed Energy (KV2/J)
Q690 steelQ690C012mm-150mm≥55
Impact test to take longitudinal samples.


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