Introduction of high weather-resistant steel Q355GNH

High weather-resistant steel Q355GNH, also known as atmospheric corrosion-resistant steel, is a low-alloy steel series that exists between stainless steel and ordinary steel. A small amount of corrosion-resistant elements such as copper and nickel are added to ordinary carbon steel to make it have the characteristics of high-quality steel such as plastic extension, welding and cutting, toughness, abrasion, forming, fatigue resistance, and high temperature; the paintability is 10 times that of ordinary carbon steel, The weather resistance is 8 times that of ordinary carbon steel, forming a new type of steel—weather steel. At the same time, it also has the characteristics of rust resistance, corrosion resistance and life extension of components.

Classification of high weather-resistant steel

There are four kinds of high weather-resistant steel, namely Q355GNH, Q310GNH, Q265GNH, Q295GNH, and these four kinds of high weather-resistant steel are also its grades; welding weather-resistant steel is divided into seven grades according to the standard, namely Q550NH, Q295NH, Q500NH, Q415NH , Q460NH Q235NH, Q355NH seven.

The chemical composition of high weather-resistant steel Q355GNH

C: ≤0.12

S: 0.20~0.75

Mn: ≤1.00

P: 0.07~0.75

S: ≤0.020

Cu: 0.25~0.55

Cr: 0.30~1.25

Ni: ≤0.25

Mechanical properties of high weather-resistant steel Q355GNH:

Tensile strength: ≥490~630Mpa

Yield strength: ≤355

Growth rate: ≤26

High weather-resistant steel Q355GNH is often used to manufacture structural parts such as railway vehicles, seaport buildings, containers, oil production platforms, chemical petroleum equipment, and containers containing hydrogen sulfide corrosive media in oil derricks. It can also be used to manufacture towers, railways, bridges, vehicles and other steel structures exposed to the atmosphere for a long time.

The difference between Q355GNH and Q355NH

The difference between Q355GNH high weather resistance steel and Q355NH weather resistance steel is mainly in the chemical composition and mechanical properties. Let's compare their differences below:

The chemical composition of Q355GNH high weather-resistant steel:

C: ≤0.12

S: 0.20~0.75

Mn: ≤1.00

P: 0.07~0.75

S: ≤0.020

Cu: 0.25~0.55

Cr: 0.30~1.25

Ni: ≤0.25

Chemical composition of Q355NH high weather-resistant steel:

C: ≤0.16

Si: ≤0.50

Mn: 0.50~1.50

P: ≤0.030

S: ≤0.030

Mo: ≤0.30

Cu: 0.25~0.55

Ti: ≤0.10

V: ≤0.12

Nb: ≤0.06

Cr: 0.40~0.80

Mechanical properties of Q355GNH high weather-resistant steel:

Tensile strength: ≥490~630Mpa

Yield strength: ≤355

Growth rate: ≤26

Mechanical properties of Q355NH high weather-resistant steel:

Tensile strength: ≥516~670Mpa

Yield point: ≥355

High weather-resistant steel Q355NH is a weather-resistant steel plate, and high weather-resistant steel Q355GNH is a weather-resistant steel plate, both of which belong to the low-alloy series. In addition, in terms of performance and price, the performance and composition of Q355GNH are better than those of Q355NH, and the price is also higher.