Q345 Steel, Q345A Q345B Q345C Q345D Q345E Equivalent, Specification, Chemical Composition, Properties
Q345 Steel Properties
Q345 steel is a Chinese GB standard Low Alloy High Strength Structural Steel, material density is 7.85 g/cm3, tensile strength is 470-630 Mpa, and yield strength is 345 MPa, it has better properties than Q235. According to GB/T 1591 – 2008, Q345 material has 5 quality grades: Q345A, Q345B, Q345C, Q345D and Q345E.
Q345 steel has good weldability, cold & hot workability and corrosion resistance. Widely used in bridges, ships, boilers, pressure vessels, petroleum storage tanks, lifting transport machinery and other high-load welded structural parts.
Meaning & Designation
“Q” is the first letter of Chinese Pinyin: “qu fu dian”, that means Yield Point, “345” is the minimum value of yield strength 345 MPa for steel thickness ≤16mm.
Datasheet and Specification
Datasheet and specification are listed in the tables below, including chemical composition, machenical properties, etc.
Chemical Composition of Q345 Steel
Based on melting analysis.
| Chemical Composition Content (≤%) | ||||||||||||||||
| Steel Grade | Quality Grade | C | Si | Mn | P | S | Cr | Ni | Mo | Cu | Ti | N | Nb | V | B | Als, ≥ |
| Q345 | Q345A | 0.20 | 0.50 | 1.70 | 0.035 | 0.035 | 0.30 | 0.50 | 0.10 | 0.30 | 0.20 | 0.012 | 0.07 | 0.15 | – | – |
| Q345B | 0.035 | 0.035 | ||||||||||||||
| Q345C | 0.030 | 0.030 | 0.015 | |||||||||||||
| Q345D | 0.18 | 0.030 | 0.025 | |||||||||||||
| Q345E | 0.025 | 0.020 | ||||||||||||||
Notes: The P and S contents of profiles and bars can be increased by 0.005%, and the upper limit of Grade A steel can be 0.0045%.
Material Q345 Mechanical Properties
| Mechanical Properties: Yield Strength (≥ MPa) | ||||||||||
| Steel Grade | Quality Grade | d ≤16 | 16< d ≤ 40 | 40 <d ≤ 63 | 63 <d≤ 80 | 80 < d ≤ 100 | 100 < d ≤ 150 | 150 < d ≤ 200 | 200 < d ≤ 250 | 250 < d ≤ 400 |
| Q345 | Q345A | 345 | 335 | 325 | 315 | 305 | 285 | 275 | 265 | – |
| Q345B | ||||||||||
| Q345C | ||||||||||
| Q345D | 265 | |||||||||
| Q345E | ||||||||||
Notes:
- d= Thickness or wire diameter in mm;
- 1 MPa = 1 N/mm2
| Mechanical Properties: Tensile Strength (MPa) | ||||||||
| Grade | Quality Level | d≤ 40 | 40 <d ≤ 63 | 63 <d ≤ 80 | 80 <d≤ 100 | 100 < d≤ 150 | 150 < d ≤ 250 | 250 < d ≤ 400 |
| Q345 | Q345A | 470-630 | 470-630 | 470-630 | 470-630 | 450-600 | 450-600 | – |
| Q345B | ||||||||
| Q345C | ||||||||
| Q345D | 450 – 600 | |||||||
| Q345E | ||||||||
| d mm, Elongation (≥%) | |||||||
| Grade | Quality Level | d≤40 | 40 <d ≤ 63 | 63 < d≤ 100 | 100 <d≤ 150 | 150 < d ≤ 250 | 250 <d ≤ 400 |
| Q345 | Q345A | 20 | 19 | 19 | 18 | 17 | – |
| Q345B | |||||||
| Q345C | 21 | 20 | 20 | 19 | 18 | ||
| Q345D | 17 | ||||||
| Q345E | |||||||
Charpy Impact
Charpy (V-notch) impact test temperature and impact absorption energy (KV2/J), thickness (t).
| Quality | Temperature, °C (°F) | 12-150 (mm) | 150<t≤250 (mm) | 250<t≤400 (mm) |
| Q345B | 20 (68) | ≥34J | ≥27J | – |
| Q345C | 0 (32) | |||
| Q345D | -20 (-4) | 27J | ||
| Q345E | -40 (-40) |
Material Q345 Equivalent
Q345 steel: Q345A, Q345B, Q345C, Q345D, Q345E equivalent to US ASTM, European Germany DIN, British BS, France NF, Japan JIS, and ISO Standard (For Reference).
Notes: Q345 steel has been replaced by Q355 in the latest version of GB standard “GB/T 1591 – 2018”, the previous version is “GB/T 1591 – 2008”.
| Low Alloy Structural Steel Q345 Equivalent | |||||||||||||
| China | US | Germany | Japanese | ISO | |||||||||
| Standard | Grade | Standard | Standard | Grade (steel number) | Standard | Grade | Standard | Grade | |||||
| GB/T 1591 – 2008 (Year) | Q345A | ASTM A529 Grade 50; ASTM A572 Grade 50; ASTM A588 Grade 50; ASTM A678 Grade 50 |
JIS G3135 | SPFC590 | ISO 630-2 | S355C, S355D (S355) | |||||||
| GB/T 1591 – 2008 | Q345B | DIN EN 10025-2; DIN 17100 |
S355, S355JR (1.0045), E355 (1.0060); St52-3 |
JIS G3135 | SPFC 590 | ISO 630-2 | S355C, S355D (S355) | ||||||
| GB1591 – 2008 | Q345C | DIN EN 10025-2; DIN 17100 |
S355J0 (1.0553), E335 (1.0060); St52-3 |
JIS G 3135 | SPFC590 | ISO 630-2 | S355D (S355) | ||||||
| GB 1591 – 2008 | Q345D | ASTM A656 Grade 50; ASTM A529 Grade 50 |
DIN EN 10025-2; DIN EN 10025: 1993; DIN 17100 |
S355J0 (1.0553), E335 (1.0060); S355J2G3 (1.0570); St52-3 |
JIS G 3135 | SPFC590 | ISO 630-2 | S355D (S355) | |||||
| GB/T 1591 – 2008 | Q345E | ASTM A656/A656M Grade 50; ASTM A529/A529M Grade 50; ASTM A808 Grade 50 |
DIN EN 10025-2; DIN EN 10025: 1993 |
S355J2 (1.0553), S355K2 (1.0596), E335 (1.0060); S355J2G4 (1.0577), S355K2G3 (1.0595), S355K2G4 (1.0596) |
JIS G3135 | SPFC 590 | |||||||
Tags: Q345A steel, Q345B steel, Q345C steel, Q345D steel, Q345E steel
Related material: SS400 Steel, SUJ2 Steel, 304 Stainless Steel
I sent an enquiry on this yesterday if the Q345 material can withstand caustic without corroding. We want to fabricate a tanker for transporting caustic on long distance.
Kindly respond.
Thanks
Hi, Fred, so sorry that we don’t sell steel products.
What’s the brinell scale of Q345B