Q345B large-diameter seamless square steel pipe is a long steel product with a hollow section and no seams, which is made of seamless steel pipe as the base material through rolling or cold drawing. Compared with solid steel materials such as round steel, large-diameter seamless square steel pipes are lighter in weight when the bending and torsional strength are the same. They are an economical cross-section steel and are widely used in manufacturing structural parts and mechanical parts.

Q345B large-diameter seamless square steel pipes can be divided into square steel pipes and special-shaped steel pipes according to different cross-sectional area shapes. When the circular cross-section is subjected to internal or external radial pressure, the force is relatively uniform. Therefore, the vast majority of steel pipes are circular pipes. However, circular pipes also have certain limitations. For example, under the condition of plane bending, the circular pipe will It is not as strong as seamless square steel pipes and rectangular pipes in bending strength. Square and rectangular pipes are commonly used in some agricultural machinery frames, steel and wood furniture, etc. Special-shaped steel pipes with other cross-sectional shapes are also required according to different uses.

What are the advantages of Q345B large diameter square steel pipe?
1. The surface of Q345B large-diameter square steel pipe is more durable and has anti-rust and anti-rust treatment. The oxidation rate will not be too fast and white rust will not form on the square steel pipe.
2. It has anti-corrosion and wear-resistant properties, making the seamless steel pipe have a longer service life.
3. Seamless steel pipes are protected. After heating, hot-dip galvanizing is performed on each position of the seamless steel pipe, and the convex and concave positions are protected.
4. Because the seamless steel pipe is hot-dip galvanized on the outside, it saves the time of painting or brushing, making the construction more convenient.
5. Hot-dip galvanized steel pipes will not freeze or break even within 39 days, making them very suitable for northern regions.

During the project acceptance of Q345B large-diameter square steel pipe, it is important to pay attention to the consistency of the four corners, and the deviation of the four sides is within the scope of the national standard. The national standard for the replacement of seamless square and rectangular pipes is generally: GB/T3094-2008, and it is still within this standard. The dimensional error of the R angle has been adjusted. The bright square steel pipe is much stronger than the straight seam square steel pipe in terms of bearing pressure. The price of the bright square steel pipe is at least much higher. The bright square steel pipe will have pipe ends during processing. In the case of a flat tail, choosing a tail is a supplementary measure.

Why do Q345B large-diameter square steel pipes need to be deployed? The main reason is to improve the quality of Q345B large-diameter square steel pipes, including:
(1) Regarding high carbon steel and high alloy steel, quenching can develop its strength to improve drillability.
(2) Regarding low-carbon steel, quenching can replace heat treatment to prepare for induction quenching can reduce the deformation of seamless pipes and reduce production costs.
(3) Regarding high-carbon steel, quenching can remove the network structure of cementite distribution, which is beneficial to spheroidizing annealing.
(4) For large and medium-sized seamless pipes or steel castings with significantly changed cross-sections, quenching can be used instead of heat treatment to reduce the tendency of deformation and cracking or to prepare for heat treatment.
(5) The heat-treated anti-repair parts of seamless pipes can be quenched to eliminate over-temperature damage so that they can be heat-treated again.
(6) Used in aluminum die castings to increase the normal ferrite content and improve the strength and wear resistance of castings.