Q345B seamless square tube 150 * 150 * 12

Compared with solid steel materials such as round steel, steel pipes are lighter in weight when their bending and torsional strength is the same. They are an economical cross-sectional steel material widely used in the manufacture of structural and mechanical parts, such as oil drill rods, automotive transmission shafts, bicycle frames, and steel scaffolding used in construction. Using steel pipes to manufacture circular parts can improve material utilization, simplify manufacturing processes, save materials and processing time, such as rolling bearing rings, jack sleeves, etc. Steel pipes were used for manufacturing in 2013. Steel pipes are still an indispensable material for various conventional weapons, such as gun barrels and cannon barrels, which require steel pipes for manufacturing. Steel pipes can be divided into circular pipes and special-shaped pipes according to their cross-sectional area and shape. Due to the fact that the circular area is the largest under the condition of equal circumference, a circular tube can transport more fluid. In addition, when subjected to internal or external radial pressure, the circular cross-section is subjected to more uniform force, therefore, the vast majority of steel pipes are circular.

1. Performance index analysis of square tube - plasticity

Plasticity refers to the ability of metal materials to undergo plastic deformation (permanent deformation) under load without failure.

2. Performance index analysis of square tube - hardness

Hardness is a pointer to measure the softness and hardness of metal materials. The most commonly used method for measuring hardness in production is the indentation hardness method, which uses a certain geometric shape of the indenter to press into the surface of the tested metal material under a certain load, and determines its hardness value based on the degree of pressing.

The commonly used methods include Brinell hardness (HB), Rockwell hardness (HRA, HRB, HRC), and Vickers hardness (HV).

3. Performance index analysis of square tube - fatigue

The strength, plasticity, and hardness discussed earlier are all indicators of the mechanical properties of metals under static loads. In fact, many machine parts work under cyclic loads, and under these conditions, the parts will experience fatigue. The road also requires special-shaped steel pipes with other cross-sectional shapes.

1. Welded steel pipes for low-pressure fluid transportation (GB/T3092-1993), also known as general welded pipes, commonly known as black pipes. It is a welded steel pipe used for transporting generally low-pressure fluids such as water, gas, air, oil, and heating steam, as well as for other purposes. The wall thickness of steel pipes is divided into ordinary steel pipes and thickened steel pipes; The form of the connecting end is divided into non threaded steel pipe (plain pipe) and threaded steel pipe. The specifications of steel pipes are expressed in nominal diameter (mm), which is an approximate value of the inner diameter. It is commonly expressed in inches, such as 11/2. Welded steel pipes for low-pressure fluid transportation are not only directly used for transporting fluids, but also widely used as raw pipes for galvanized welded steel pipes for low-pressure fluid transportation.

2. Galvanized welded steel pipes for low-pressure fluid transportation (GB/T3091-1993), also known as galvanized welded steel pipes, commonly known as white pipes. It is a hot-dip galvanized welded (furnace welding or electric welding) steel pipe used for transporting water, gas, air oil, heating steam, warm water and other generally low-pressure fluids or other purposes. The wall thickness of steel pipes is divided into ordinary galvanized steel pipes and thickened galvanized steel pipes; The types of takeover ends are divided into non threaded galvanized steel pipes and threaded galvanized steel pipes.

3. Ordinary carbon steel wire conduit (GB3640-88) is a steel pipe used to protect wires in electrical installation projects such as industrial and civil buildings, and installation of machinery and equipment.

4. Straight seam welded steel pipe (YB242-63) is a steel pipe with a weld seam parallel to the longitudinal direction of the steel pipe. Usually divided into metric welded steel pipes, welded thin-walled pipes, transformer cooling oil pipes, etc.

5. Spiral seam submerged arc welded steel pipe (SY5036-83) for pressurized fluid transportation is a spiral seam steel pipe made of hot-rolled steel strip coil as pipe blank, formed by constant temperature spiral forming, welded by double-sided submerged arc welding method, and used for pressurized fluid transportation. Steel pipes have strong pressure bearing capacity and good welding performance. After various rigorous scientific inspections and tests, they are safe and reliable to use. The steel pipe has a large diameter, high conveying efficiency, and can save investment in laying pipelines. Mainly used for pipelines transporting oil and natural gas.