Low Alloy High Strength Steel Sheets: Q390 and Q460

1. Overview

Q390 and Q460 are low alloy high strength structural steels specified by the Chinese standard GB/T 1591-2018. They contain small amounts of alloying elements (e.g., manganese, silicon, niobium, vanadium) to achieve higher strength and better comprehensive properties than ordinary carbon steel, while maintaining good weldability and formability.

2. Grades and Mechanical Properties

Grade	Yield Strength \(R_eL\) (MPa) (Thickness ≤ 16mm)	Tensile Strength \(R_m\) (MPa)	Elongation A (%)	Impact Test (Temperature, Energy)
Q390	≥390	490–650	≥17	+20℃, ≥34J (Charpy V-notch)
Q460	≥460	550–720	≥17	+20℃, ≥34J (Charpy V-notch)

 

Key Notes:

Higher grades (e.g., Q460) offer significantly greater load-bearing capacity than lower grades (e.g., Q345).

For thicker plates (>16mm), yield strength decreases slightly (e.g., Q460 with thickness 16–100mm has \(R_eL\) ≥420 MPa).

3. Chemical Composition (Typical Values, %)

Grade	C	Si	Mn	P	S	Nb	V	Ti	Alt
Q390	≤0.20	0.20–0.55	1.00–1.60	≤0.035	≤0.035	0.015–0.060	0.015–0.060	0.02–0.20	≥0.015
Q460	≤0.18	0.20–0.60	1.00–1.70	≤0.030	≤0.030	0.020–0.070	0.020–0.080	0.02–0.20	≥0.015

 

Alloying Elements Role:

Niobium (Nb), Vanadium (V), Titanium (Ti): Refine grain structure, improve strength and toughness.

Manganese (Mn): Enhances hardenability and strength.

Aluminum (Alt): Acts as a deoxidizer and stabilizes grain size.

 

 

 

 

 

 

 

 

 

 

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 Low Alloy&High Strength Steel Sheetq460 Q390, 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.

Hot Tags: low alloy&high strength steel sheetq460 q390, China low alloy&high strength steel sheetq460 q390 suppliers, factory, HR500LA, CR240LA, CR1 Steel, CR300LA, CR2 Steel, HR0 Steel