Q345 is a low-alloy steel widely used in Bridges, vehicles, ships, construction, pressure vessels, special equipment, etc. “Q” means yield strength and 345 means yield strength of this steel is 345MPa.Of the low alloy materials, Q345 is the most common. Q345 used to be called 16Mn.

Q345 will reduce its yield value with the thickness of the material.In addition, the output of China may be less than 345, so the strength of mechanical design must be less than 345, otherwise there will be problems.

Q345 is also divided into A, B, C, D and E grades.The difference of grade mainly lies in the difference of impact temperature.

Q345A: no impact

Q345B: impact at room temperature of 20℃

Q345C: 0℃ impact

Q345D: impact at -20℃

Q345E: impact at -40℃

External standard of Q345: GB709, internal standard: GB/ t1591-2008

Due to the implementation of the standard, this steel plate allows negative tolerance delivery.

The chemical composition of Q345 material is as follows:

Q345A: C≤0.20, Mn ≤1.70, Si≤0.50, P≤0.035, S≤0.035;

Q345B: C≤0.20, Mn ≤1.70, Si≤0.50, P≤0.035, S≤0.035;

Q345C: C≤0.20, Mn ≤1.70, Si≤0.50, P≤0.030, S≤0.030, Al≥0.015;

Q345D: C≤0.18, Mn ≤1.70, Si≤0.50, P≤0.030, S≤0.025, Al≥0.015;

Q345E: C≤0.18, Mn ≤1.70, Si≤0.50, P≤0.025, S≤0.020, Al≥0.015;

Q345A, B, C, D and E all contain Nb≤0.07, V≤0.15, Ti≤0.20, Cr≤0.30, Ni≤0.012, Mo≤0.10.

Compared with Q235, Q345 material has different yield strength

The lower limit of yield strength of Q235 is 235Mpa, and that of Q345 is 345Mpa (Q means “qu” in Chinese, and the following value represents the lower limit of yield strength).

They have different gold content: Q235 is ordinary carbon steel, Q345 is low alloy steel.

Mechanical properties of Q345:

Mechanical properties of Q345D seamless pipe:

Tensile strength: 490-675mpa yield strength: ≥345MPa elongation: ≥22%

Mechanical properties of Q345B seamless pipe:

Tensile strength: 490-675mpa yield strength: ≥345MPa elongation: ≥21%

Mechanical properties of Q345A seamless pipe:

Tensile strength: 490-675mpa yield strength: ≥345MPa elongation: ≥ 21%

Mechanical properties of Q345C seamless pipe:

Tensile strength: 490-675mpa yield strength: ≥345MPa elongation: ≥22%

Mechanical properties of Q345E seamless pipe:

Tensile strength: 490-675mpa yield strength: ≥345MPa elongation: ≥22%

The Q345 material is widely used by people nowadays. Let’s have a look at the small field of application of Q345 material that I have recently come into contact with.

This is the hilt part of a sword, and the circle at the front is a small counterweight made from Q345B material. It is small, but it has a great effect, which increases the weight of hilt part and makes users safer in fencing.

The material of Q345 is very common in life. Although it is not inseparable from Made in China, most of the time we cannot do without Made of Q345.For example, the automobile, everywhere can be seen, a car parts are many, many and a number of cold stamping parts.Many of the cold stamping parts, which account for 50% to 60% of the total number of auto parts, are made by Q345.

All in all, Q345 is a good low-alloy steel, which is widely used in life. Of course, if you have any questions or requirements in this aspect, please join us.Let’s communicate together.

 

 

Eternal Bliss Alloy Casting & Forging Co, Ltd.

Technical Dept.

Telephone: 18800596372

E-mail: sales@ebcastworld.com

Justin.