Q690D Steel Late Introduction

1, Q690D belongs to low alloy high strength structural steel plate, Q690D implementation standard for GB/T1591-2008 special technical conditions.

Q690D itself not only has this very high strength but also has a certain flexibility, wear resistance, fatigue resistance, impact resistance, easy processing and wear resistance, often used in the manufacturing industry for example; Mining machinery, crane, iron anchor, shield machine, hydraulic support, port machinery, Marine equipment bridge structure, etc

2, Q690D because it has enough high quality performance

First, it meets the needs of many manufacturing industries in material selection

Second, the high quality performance in the process of use has also been deeply loved and praised by the manufacturing industry. Later, because of the recognition of the society, the frequent use of the manufacturing industry and the continuous optimization of the manufacturer, Q690D has gradually become one of the commonly used raw materials in the manufacturing industry.

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 <CLASS C D E> are displayed in the following table.

Q690 Chemical Composition (%)

Steel GradeQuality GradeCSiMnPSNbVTiCrNiCuNMoBAl
Q690C≤ 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

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 ClassTest Temp. (℃)ThicknessAbsorbed Energy (KV2/J)
Q690 steelC012mm-150mm≥55
Impact test to take longitudinal samples.