Basic Overview of Q345 Series Steel

Q345 is a low-alloy high-strength structural steel specified in China's GB/T 1591 standard. The "Q" denotes yield strength, and "345" indicates a minimum yield strength of 345 MPa.

 

It is classified into grades such as Q345A, Q345B, and Q345C based on impact toughness and delivery conditions. The main differences are as follows:

 

Grade	Impact Test Temperature	Impact Absorption Energy (KV2, ≥J)	Delivery Condition	Application Scenario Characteristics
Q345A	No requirement	-	Hot-rolled/Normalized	Ordinary structures in non-freezing 常温 non-severe cold areas
Q345B	20℃ (ambient temperature)	34	Hot-rolled/Normalized	Structures 承受 dynamic loads in temperate zones
Q345C	0℃	34	Normalized	Structures in cold areas (-20℃ and above)

 

 

 

 

 

Application Scenarios and Selection Tips

Main Application Fields

Construction Engineering: High-rise building frames, large-span factories, gymnasium space frames (commonly using Q345B/C).

Bridge Engineering: Steel structures for highway and railway bridges (Q345C is preferred, requiring welding procedure qualification).

Mechanical Manufacturing: Crane booms, mining machinery structural components (requiring quenching and tempering to enhance strength).

 

Selection Key Points

Environmental Temperature: Prioritize Q345C in subzero regions to avoid cold brittleness fracture; choose Q345B for ambient temperature environments to reduce costs.

Load Type: Dynamic loads (e.g., vibration, impact) require higher impact toughness, while static loads allow looser requirements.

Processing Technology: For welded structures, pay attention to the carbon equivalent (CEV) – Q345C has a lower CEV and better weldability.

 

Why Choose Us?
We take pride in our ability to provide custom solutions for our customers' unique needs.
We analyze and compare the previous products and the current technical situation of our Q345 Q345A Q345B Q345C Alloy Steel Plate Hot Sale, and develop new technical specifications and processes.
Our customers trust us to deliver high-quality Cold-rolled Steel products on time and on budget.
We strictly implement the warm and thoughtful after-sales service, adhere to the development of good professional ethics.
We offer a wide range of Cold-rolled Steel products to meet diverse customer needs.
We adhere to the customer-centric and brand-oriented business philosophy, and continue to provide customers with reliable and excellent products and services.
Our factory is committed to upholding the highest standards of safety and quality.
All staff of our company and all departments work together to combine business management, professional technology, quantitative statistical methods and ideological education.
Our Cold-rolled Steel products are known for their durability and reliability.
Relying on the superior conditions and strong advantages of mass production, we are able to meet the different needs of our customers.

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