Factory Promotional Hot Rolled Thick Wall Steel Pipe - Q345D low temperature resistant steel pipe quality assurance – Weichuan

Good comprehensive mechanical properties, weldability, cold and hot workability and corrosion resistance, and good low temperature toughness

Ships, boilers, pressure vessels, oil storage tanks, bridges, power station equipment, hoisting and transportation machinery and other welded structural parts with high load

18nb killed steel containing Nb, with properties similar to 14MnNb, is mainly used for cranes, blowers, chemical machinery, etc

09mncupti atmospheric corrosion resistant steel has good low-temperature impact toughness, weldability and cold and hot workability. It is mainly used for all kinds of machinery in humid and rainy areas and corrosive atmosphere environment

12mnv low temperature steel with working temperature of – 70 ℃ is mainly used for structural parts of refrigeration machinery working at low temperature

14MnNb has similar properties to 18nb steel and is mainly used for vessels and other structural parts with working temperature of – 20-450 ℃

16Mn has good comprehensive mechanical properties, low temperature performance, cold stamping performance, welding performance and machinability. It is mainly used in mining, transportation, chemical industry and other machinery

The properties of 16mnre are similar to 16Mn steel, the impact toughness and cold bending properties are better than 16Mn, and the purpose is the same as 16Mn steel

Q345D steel pipe is one of the materials of steel pipe.

Q345D steel pipe

Q345D steel pipe

Q345A, Q345B, Q345C, Q345D and Q345E are the quality grades. They increase from a to e, mainly due to the difference in impact temperature caused by different contents of micro elements such as phosphorus and sulfur, which represents the difference in impact temperature and mechanical properties of pipe chemical composition.

Q345A, no impact; Q345B, 20 ° normal temperature impact; Q345C, 0 degree impact; Q345D, is – 20 degree impact; Q345E is – 40 degree impact. At different impact temperatures, the impact values are also different.

Q the yield strength is not lower than 345mp, and the quality grade indicates that it contains impurity elements (carbon, manganese, silicon, sulfur and phosphorus). Is the amount of impurities (elements) in the steel. The later the A, B, C and D, the less the impurity content

Q345A contains both phosphorus and sulfur less than or equal to 0.045%

Q345B contains both phosphorus and sulfur less than or equal to 0.040%

Q345C contains both phosphorus and sulfur less than or equal to 0.035%

Q345D contains both phosphorus and sulfur less than or equal to 0.030%

Q345E contains both phosphorus and sulfur less than or equal to 0.025%

The more phosphorus and sulfur impurities in steel, the worse the impact toughness

Q345A -

Q345B Akv not less than 34 at 20 ℃

At Q345C 0 ℃, Akv shall not be less than 34

Q345D – Akv not less than 34 at 20 ℃

At Q345E – 40 ℃, Akv is not less than 27

The final reason is that the reduction of P and s impurities in steel promotes the improvement of impact toughness at low temperature. One is the chemical composition of Q345 and the other is the mechanical properties of Q345.

C:≤0.18 Si:0.20-0.60 Mn:1.00-1.60 P:≤0.030 S:≤0.030 Ni:≤0.30 Cr≤0.30 Cu:≤0.20 Al:≥0.015 V:0.02-0.15 Nb:0.015-0.06

Chemical composition of Q345B seamless pipe:

C:0.12-0.20 Si:0.20-0.60 Mn:1.00-1.60 P:≤0.040 S:≤0.040 Ni:≤0.30 Cr:≤0.30 Cu:≤0.20 V:0.02-0.15 Nb:0.015-0.06

Chemical composition of Q345A seamless pipe:

C:0.12-0.20 Si:0.20-0.60 Mn:1.00-1.60 P:≤0.045 S:≤0.045 Ni:≤0.30 Cr:≤0.30 Cu:≤0.20 V:0.02-0.15 Nb:0.015-0.06

Chemical composition of Q345C seamless pipe:

C:0.12-0.20 Si:0.20-0.60 Mn:1.00-1.60 P:≤0.035 S:≤0.035 Ni:≤0.30 Cr:≤0.30 Cu:≤0.20 Al:≥0.015 V:0.02-0.15 Nb:0.015-0.06

Chemical composition of Q345E seamless pipe:

C:≤0.18 Si:0.20-0.60 Mn:1.00-1.60 P:≤0.025 S:≤0.025 Ni:≤0.30 Cr≤0.30 Cu:≤0.20 Al:≥0.015 V:0.02-0.15 Nb:0.015-0.06

Mechanical properties of Q345D seamless steel pipe:

Tensile strength: 490-675 yield strength: ≥ 345 elongation: ≥ 22

Mechanical properties of Q345B seamless pipe:

Tensile strength: 490-675 yield strength: ≥ 345 elongation: ≥ 21

Mechanical properties of Q345A seamless pipe:

Tensile strength: 490-675 yield strength: ≥ 345 elongation: ≥ 21

Mechanical properties of Q345C seamless pipe:

Tensile strength: 490-675 yield strength: ≥ 345 elongation: ≥ 22

Mechanical properties of Q345E seamless pipe:

Tensile strength: 490-675 yield strength: ≥ 345 elongation: ≥ 22