Q345 Steel Plate

Q345 steel  specification: Q345 steel belongs to 16Mn steel grade, usually it is produced in hot rolled state, hot rolled steel plate, hot rolled steel coil/sheet, it has comprehensive mechanical and welding property, as it shows good performance in structural purposes, it is widely used as welding structural part in manufacturing of ship, railway and vehicles, bridges, boiler, pressure vessel container, steel oil tank, etc. Yield point of Q345 steel plate decreases as plate thickness increases.

Q345 steel properties: welding property of Q345 steel is occasionally questioned by end users, although welding property is mainly affected by its chemical content, its production technology has been improved after all those years of research, and has been proved to be one excellent steel standard for steel structure purposes, you can contact us if there’s any doubt in your mind.  

Application difference Q345 - Q235

As Q345 and Q235 alloy element content is different, their applications are quite different.  

  • Q235 carbon structural steel is made for metal construction that doesn’t have high demand for steel strength, tie rod, connecting rod, hook, coupler, bolt and nut, sleeve, shaft and welding parts.

  • Q345 is low alloy structural steel with good mechanical properties, low temperature performance, plasticity and good weldability, it is mostly used in low pressure vessel, oil tank, vehicles, cranes, mining machinery, power stations, mechanical parts, building structure, general metal parts, Q345 steel plate is always delivered in hot rolled or normalizing state, can be used in areas where its temperature is above -40 ℃.

Q345 Steel Chemical Property

Steel Standard Steel Grade Chemical Composition
C≤ Mn Si≤ P≤ S≤ V Nb Ti Al≥
Q345 A 0.20 1.00~1.60 0.55 0.045 0.045 0.02~0.15 0.015~0.060 0.20 -
B 0.20 1.00~1.60 0.55 0.040 0.040 0.02~0.15 0.015~0.060 0.20 -
C 0.20 1.00~1.60 0.55 0.035 0.035 0.02~0.15 0.015~0.060 0.20 0.015
D 0.20 1.00~1.60 0.55 0.030 0.030 0.02~0.15 0.015~0.060 0.20 0.015
E 0.20 1.00~1.60 0.55 0.025 0.025 0.02~0.15 0.015~0.060 0.20 0.015

Q345 Steel Mechanical Property

Steel Standard Steel Grade Yield Strength Mpa Tensile Stregth Map Elongation %
Q345 A 345 470~630 21
B 345 470~630 21
C 345 470~630 22
D 345 470~630 22
E 345 470~630 22

Mechenical Property Comparision of Q345/Q235/S355

Steel Grade Tensile strength Yield strength Elongation afrer fracture
S355 450-630Mpa ≥355MPa 21-22%
S500MC 550-700Mpa ≥500MPa ≥12%
Q345B 490-675Mpa ≥345Mpa ≥21%
Q235B 375-500Mpa ≥235Mpa ≥26%

Chemical Composition Comparision of Q345/Q235/S355

Steel Grade C Si Mn P S
S355 ≤0.22 ≤0.55 ≤1.60 ≤0.025 ≤0.025
S500MC ≤0.12 ≤0.50 ≤1.70 ≤0.025 ≤0.015
Q345B ≤0.20 ≤0.50 ≤1.70 ≤0.035 ≤0.035
Q235B ≤0.20 ≤0.35 ≤1.40 ≤0.045 ≤0.045

Q345 Steel Equivalent Standard(ASTM/EN/JIS)

Steel for boiler and other pressure vessels GB 713-2008
ASTM A537-08
JIS G3115
Q245R (20g/20R); Q345R (16Mng/16MnR)
Class 1/2/3
SPV235; SPV315; SPV355
High strength low alloy structural steel GB/T 1591-2008
EN 10028-3-2003
EN 10025-2004
ASTM A572-07
ASTM A588-05
Q345 (A/B/C/D/E); Q390; Q420
Grade 50; Grade 60
Grade A; Grade B



*Haizhongjin has 16 years of experience in steel export and is a high-quality steel manufacturer in China. This data is for reference only. If you have any questions or needs, you are welcome to post your message to the form at the end of the article/static/upload/images/4f81818cbf1d968cc2d32ee0bb0b4d4d.png, and we will reply you as soon as we receive the email.

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