Q355NHD weathering steel characteristics and application range

Q355NHD weathering steel concept

Q355NHD weathering steel is a low carbon, low silicon, low phosphorus, low sulfur, high strength and low alloy structural steel, belonging to the welding type weathering steel, with excellent atmospheric corrosion resistance. Its brand is composed of the first letter of "yield strength" and "weather resistance" in Chinese pinyin, as well as the lower limit value of yield strength and quality grade. Among them, "Q" represents the yield strength, "355" indicates that the lower limit of the lower yield strength of the steel is 355MPa, and "NHD" represents its weather resistance and quality grade.

Q355NHD weathering steel features

High strength: The yield strength of Q355NHD weathering steel reaches 355MPa, and the tensile strength is as high as 470~630MPa, showing its excellent high strength characteristics.

High toughness: The steel has a high impact toughness and can maintain structural integrity and stability in a variety of harsh environments.

Good weather resistance: By adding a small amount of alloying elements, such as Cu, P, Cr, Ni, etc., Q355NHD weathering steel can form a protective layer on the surface of the metal matrix, thereby improving its atmospheric corrosion resistance.

Excellent welding performance: Q355NHD weathering steel has good welding performance, which is convenient for various welding operations in engineering.

Good processing performance: the steel can be cut, bending and other processing operations, convenient engineering applications.

Q355NHD weather-resistant tempering chemical component

The main chemical composition of Q355NHD weathering steel includes carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S) and a small amount of chromium (Cr), nickel (Ni), molybdenum (Mo) and other alloying elements. The addition of these alloying elements makes Q355NHD weathering steel have higher strength and toughness, while maintaining good weldability and machinability. Specifically, the content range of its chemical composition is as follows:

C: ≤0.16%

Si: ≤0.5%

Mn: 0.5~1.5%

P: ≤0.03%

S: ≤0.03%

Ni: ≤0.65%

Cr: 0.4~0.8%

Mo: ≤0.3%

In addition, alloying elements such as Nb, V and Ti can be added according to needs to improve its performance.

Q355NHD weathering steel application range

Q355NHD weathering steel is widely used in various fields due to its excellent performance characteristics:

Construction field: Used in the manufacture of high-rise buildings, Bridges, highways and other structural parts. Its high strength and weather resistance enable the building to withstand greater loads and harsher environmental conditions.

Vehicle field: Used to manufacture automobile shell, compartment and other parts. Its good weather resistance and mechanical properties improve the durability and safety of the vehicle.

Marine field: Used to manufacture hull, deck and other components. Its corrosion resistance and mechanical properties enable the ship to operate stably in the Marine environment for a long time.

Other fields: It is also used in petrochemical, electric power and other fields, such as making storage tanks, pipelines and other equipment. Its corrosion resistance and mechanical properties meet the demand for high-performance steels in these fields.