Q345 Medium Heavy Plate

Sanhe Steel is a professional manufacturer and supplier of Q345 Medium Heavy Plates in China. We have our own factory and strictly follow relevant standards. We supply various grades and specifications of Q345 medium and heavy plates, providing you with stable product quality and professional supply services.

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Product Description

Product and Execution Standard Description

Q345 Medium Heavy Plate is a type of low-alloy medium-thick plate. It was formerly known as 16Mn and belongs to the most commonly used basic material in the low-alloy series. The name "Q" represents the yield strength, "345" indicates that the lower limit of the yield strength at room temperature is 345 MPa. Its comprehensive mechanical properties are excellent, and it is widely used as a structural material in the construction and engineering fields.

The external execution standard for Q345 Medium Heavy Plate is GB709, and the internal execution standard is GB/T 1591-2008. The normal usage state is hot rolling or annealing. Due to the requirements of the execution standards, this type of steel plate allows for negative tolerance delivery. During the procurement process, the tolerance range can be confirmed according to actual needs.

Quality grade classification and impact requirements

The Q345 Medium Heavy Plate is divided into five quality grades: A-E. The main difference lies in the different impact test temperatures. The specific requirements are as follows:

1. Q345A grade: No impact test is conducted, meeting the requirements for normal temperature scenarios;

2. Q345B grade: Conducts a 20℃ normal temperature impact test, suitable for general environment structural components;

3. Q345C grade: Conducts an 0℃ impact test, suitable for low-temperature environment foundation structures;

4. Q345D grade: Conducts a -20℃ impact test, suitable for light-load structures in cold regions;

5. Q345E grade: Conducts a -40℃ impact test, with the lowest phosphorus and sulfur content, suitable for cold regions and harsh conditions.

The impact values of the products vary under different impact temperatures. The higher the grade, the better the low-temperature toughness.

Core mechanical performance parameters

The mechanical properties of Q345 Medium Heavy Plate are significantly influenced by thickness. The core parameters are as follows:

1. Yield strength: The lower limit at room temperature is 345 MPa. It decreases as the material thickness increases. Domestic products may be lower than 345 MPa;

2. Tensile strength: The normal range is 490-675 MPa. In some scenarios, it is 470-630 MPa;

3. Elongation rate: ≥ 21%. In normal usage, the elongation rate can reach over 22%;

4. Processing performance: The welding and processing performance are good. Processing can be carried out without complex pre-treatment;

5. Design considerations: During mechanical design, it is necessary to ensure that the mechanical strength is less than 345 MPa to avoid safety hazards.

Chemical composition details

Grade Q345	C（≤%）	Mn（≤%）	Si（≤%）	P（≤%）	S（≤%）	Al（≥%）	Common Components（≤%）
Q345A/B	0.20	1.70	0.50	0.035	0.035	-	Nb≤0.07，V≤0.15，Ti≤0.20，Cr≤0.30，Ni≤0.012，Mo≤0.10
Q345C	0.20	1.70	0.50	0.030	0.030	0.015	Nb≤0.07，V≤0.15，Ti≤0.20，Cr≤0.30，Ni≤0.012，Mo≤0.10
Q345D	0.18	1.70	0.50	0.030	0.025	0.015	Nb≤0.07，V≤0.15，Ti≤0.20，Cr≤0.30，Ni≤0.012，Mo≤0.10
Q345E	0.18	1.70	0.50	0.025	0.020	0.015	Nb≤0.07，V≤0.15，Ti≤0.20，Cr≤0.30，Ni≤0.012，Mo≤0.10

Special Performance Description

Q345 Medium Heavy Plate possesses two core special features, suitable for different application scenarios:

1. Thickness Direction Performance: In some applications, specific thickness direction performance is required. This can be achieved by adding the Z-direction performance grade symbol after the material code, such as Q345BZ15;

2. Low Temperature Impact Performance: It has outstanding impact resistance in low-temperature environments, especially for grade E products, which can be applied to various structures in cold regions with temperatures below -40℃.

The core difference from Q235 carbon steel

Compared to Q235 carbon steel, Q345 Medium Heavy Plate has significant advantages due to the addition of alloy elements such as manganese and vanadium:

1. Superior mechanical properties: Higher yield strength, better low-temperature toughness, suitable for more demanding loading scenarios;

2. Broader application range: Can be used in environments above -40℃ for structural components, showing significant advantages in medium and low-pressure vessels, mechanical equipment, and construction in cold regions.

Application fields

Q345 Medium Heavy Plate, with its excellent performance, is widely applied in several key fields:

1. Construction Engineering: It is used for the load-bearing parts of building structures to ensure the stability of the building;

2. Bridge Construction: As the main structural material for bridges, especially Q345qC, Q345qD, and Q345qE special steel for bridges;

3. Machinery Manufacturing: It is used to manufacture various mechanical equipment and pressure vessels, suitable for medium and low pressure conditions;

4. Other Fields: It can also be used in structures and mechanical parts of vehicles, cranes, mining machinery, power stations, etc. that are subjected to dynamic loads, as well as in engineering in low-temperature environments.

Core advantages and supply guarantee

The Q345 Medium Heavy Plate has excellent comprehensive mechanical properties, outstanding low-temperature performance, plasticity and weldability. It can be used in both hot-rolled and normalized states, effectively enhancing the service life and safety of structural components, and reducing the costs of construction and maintenance. As a professional supplier, Sanhe Steel strictly controls product quality, ensuring that each batch of products complies with the GB/T 1591-2008 standard. It supplies multiple grades and specifications of products to meet the individualized needs of different fields, providing reliable material support for various projects.