Comparison Of Q345B And Q355B Steel

Q345B and Q355B steel are common low-alloy high-strength structural steel, the two have some of the following comparisons:

1. the chemical composition of carbon content: both carbon content is low, usually below 0.2%. But the specific value may be slightly different, generally speaking, the impact on performance is not particularly significant. Manganese content: Q355B manganese content may be slightly higher than Q345B, manganese helps to improve the strength and toughness of steel. Other alloying elements: all contain a small amount of silicon, vanadium, niobium and other alloying elements, play a role in refining the grain, improve strength and so on.

2. Mechanical properties strength: Q355B yield strength and tensile strength is slightly higher than Q345B. Q355B yield strength is generally above 355MPa, Q345B yield strength is generally above 345MPa. Q355B yield strength is generally above 355MPa, Q345B yield strength is generally above 345MPa, which makes Q355B more advantageous in some of the structural components with high strength requirements.

Toughness: both have good toughness, at low temperatures can still maintain a certain impact toughness. However, in the specific use of the environment, may be due to production processes and heat treatment and other factors.
Welding performance: all have good welding performance, can be connected using a variety of welding methods. But in the welding process need to pay attention to the control of welding parameters to avoid welding defects.
3. the use of building structures: are widely used in building structures, such as steel plants, bridges, high-rise buildings.
Q355B can be used in structural parts that bear greater loads due to its higher strength. Machinery manufacturing: in the field of machinery manufacturing, it can be used to manufacture cranes, mining machinery, pressure vessels and so on. According to the requirements of different equipment, choose the appropriate steel. Shipbuilding: in shipbuilding, both steels can be used for hull structure and some mechanical parts.

4. the price in general, the price of Q355B may be slightly higher than Q345B, which is mainly due to its chemical composition and performance differences.
You can choose more suitable steel for steel pipe according to your project requirements and price demand, if you have other questions you can consult us.