Overview of High Strength Steel Plates: Q345, SM490, A572

High-strength steel plates are critical materials in construction, machinery, and infrastructure due to their superior mechanical properties. Below is a detailed comparison of three widely used grades-Q345 (China), SM490 (Japan), and A572 (USA)-covering their standards, properties, applications, and key differences.

Q345 (China GB Standard)

Standard: GB/T 1591 (High-Strength Low-Alloy Structural Steel)
Classification: Low-alloy high-strength steel (HSLA) with variants (e.g., Q345B, Q345D, Q345E) differing in impact toughness and chemical composition.

Key Properties

Yield Strength: ≥345 MPa (for thickness ≤16 mm).

Tensile Strength: 470–630 MPa.

Impact Toughness:

Q345B: 27 J at +20°C (Charpy V-notch).

Q345D: 27 J at -20°C; Q345E: 27 J at -40°C (suitable for cold regions).

 

 

 

Specification we supply：

Thickness	3-200mm
Width	1500-4000mm
Length	5000-15000mm

 

 

Chemical Composition:

Low carbon (~0.20%) with alloying elements like Mn, Si, Nb, V, Ti to enhance strength and grain refinement.

Low carbon equivalent (CE) ensures good weldability.

Applications

Construction: Bridges, high-rise buildings, industrial steel structures.

Machinery: Heavy equipment frames, mining machinery, pressure vessels.

Transportation: Railway vehicles, shipbuilding (non-critical components).

Standards Update:

Replaced by Q355 in GB/T 1591-2018 (higher purity and improved toughness), but Q345 remains in use for legacy projects.

 

 

 

 

 

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 High Strength Steel Plate Q345 SM490 A572, 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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