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).
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
Q690 Chemical Composition (%) | ||||||||||||||||
| Steel Grade | Quality Grade | C | Si | Mn | P | S | Nb | V | Ti | Cr | Ni | Cu | N | Mo | B | Al |
| Q690 | C | ≤ 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 |
| D | ≤0.030 | ≤0.025 | ||||||||||||||
| E | ≤0.025 | ≤0.020 | ||||||||||||||
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 |
Charpy Impact Test of Q690 Material
| Charpy Impact Test (V) – Test temperature and impact absorbed energy | ||||
| Grade | Quality Class | Test Temp. (℃) | Thickness | Absorbed Energy (KV2/J) |
| Q690 steel | C | 0 | 12mm-150mm | ≥55 |
| D | -20 | ≥47 | ||
| E | -40 | ≥31 | ||
