Processing and Usage Precautions

Cutting and Forming

Cutting Methods: Flame cutting and plasma cutting are applicable. For thick Q420 plates, pay attention to thermal deformation control during cutting (e.g., preheating or optimized cutting sequences).

Cold Forming: Q420 requires higher-tonnage equipment for cold forming to avoid processing cracks, especially for thick sections.

Welding Key Points

Electrode Matching:

Q345: Use E50-series electrodes (e.g., E5015, E5016) for general welding.

Q420: Recommend low-hydrogen electrodes (e.g., E5515-G) to reduce hydrogen-induced cracking risks.

Preheating and Post-Weld Cooling:

For thick plates (≥30mm), preheat to 80–120°C before welding and use post-weld insulation to slow cooling, preventing cold cracks.

Anti-Corrosion Treatment

Coating: In outdoor or humid environments, apply anti-rust paints (e.g., zinc-rich primer) to protect the surface.

Weathering Grades: Opt for weather-resistant grades (e.g., Q345NH) to reduce maintenance needs in corrosive atmospheres.

 

 

 

 

 

 

Specification we supply：

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

 

 

 

 

Comparison with Other Steel Grades

vs. Ordinary Carbon Steel (e.g., Q235)

Strength: Q345 offers ≥40% higher yield strength, enabling 20–30% steel savings under the same load, though at a slightly higher cost.

Application: Ideal for load-bearing structures requiring moderate strength beyond Q235's capacity.

vs. Higher-Strength Steels (e.g., Q460)

Cost-Effectiveness: Q345–Q420 provide better value for non-extreme load scenarios, avoiding the specialized design requirements of Q460 and above.

Usage Scenarios: Q460+ grades are reserved for high-performance applications (e.g., aerospace, military), while Q345–Q420 dominate general industrial and infrastructure uses.

Summary

Q345, Q390, and Q420 are workhorse steel grades in industrial applications, offering a gradient of strength and toughness to meet diverse structural needs-from ordinary to mid-to-high-end projects. Their balanced performance, cost efficiency, and adaptability make them essential for reliable, economical engineering solutions.

 

 

 

 

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 Q390 Q420 Low Alloy High Strength Steel Plate, 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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