Professional China A178 Rectangular Pipe - Q345B thick wall square pipe quality assurance – Weichuan

Large diameter thick walled square pipe is a kind of light thick walled steel pipe with hollow square section, also known as steel cold-formed profile. It is a section steel with square section shape and size, which is made of Q235 hot-rolled or cold-rolled strip or coil as the base material, cold bending and high-frequency welding.

According to the production process, large-diameter thick wall square pipe is divided into hot-rolled thick wall square pipe, cold drawn thick wall square pipe, extruded thick wall square pipe and welded square pipe.

(a) According to the process – arc welding square tube, resistance welding square tube (high frequency and low frequency), gas welding square tube and furnace welding square tube

(b) Divided by weld – straight welded square pipe and spiral welded square pipe

Large diameter thick wall square pipe is divided into ordinary carbon steel square pipe and low alloy square pipe according to material. Ordinary carbon steel is divided into: Q195, Q215, Q235, SS400, 20# steel, 45# steel, etc; Low alloy steels are divided into Q345, 16Mn, Q390, St52-3, etc.

Square steel pipe, thick wall square steel pipe, large diameter square steel pipe, seamless square steel pipe, low alloy square steel pipe, 135 * 135 * 10 square steel pipe, square steel pipe for tower crane, Q345B low alloy square steel pipe, 20# seamless square steel pipe

Square tube, as the name suggests, is a kind of square tube. Many materials can form square tube. It is used for, what to do and where to use. Most square tubes are steel tubes, mostly structural square tubes, decorative square tubes, building square tubes, etc

Square pipe is a name for square pipe, that is, steel pipe with equal side length. It is made of rolled strip steel after process treatment. Generally, the strip steel is unpacked, leveled, crimped and welded to form a round pipe, then rolled into a square pipe, and then cut into the required length. Generally 50 pieces per package.

Square tubes can be divided into seamless and welded ones. Seamless square tubes are extruded from seamless circular tubes. Square steel pipe, thick wall square steel pipe, large diameter square steel pipe, seamless square steel pipe, low alloy square steel pipe, 135 * 135 * 10 square steel pipe, square steel pipe for tower crane, Q345B low alloy square steel pipe, 20# seamless square steel pipe

1. Performance index analysis of square tube – plasticity

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

2. Performance index analysis of square tube – hardness

Hardness is a pointer to measure the hardness and softness of metal materials. At present, the most commonly used method for measuring hardness in production is the indentation hardness method. It uses an indenter with a certain geometry to press into the surface of the tested metal material under a certain load, and determines its hardness value according to the degree of indentation.

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 above are all indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.

4. Performance index analysis of square tube – impact toughness

The load acting on the part at a great speed is called impact load, and the ability of metal to resist failure under impact load is called impact toughness.

5. Performance index analysis of square pipe – strength square steel pipe, thick wall square steel pipe, large diameter square steel pipe, seamless square steel pipe, low alloy square steel pipe, 135 * 135 * 10 square steel pipe, square steel pipe for tower crane, Q345B low alloy square steel pipe, 20# seamless square steel pipe

Strength refers to the resistance of metal materials to failure (excessive plastic deformation or fracture) under static load. Since the action modes of load include tension, compression, bending and shear, the strength is also divided into tensile strength, compressive strength, flexural strength and shear strength. There is often a certain connection between various strengths. Generally, tensile strength is used as the most basic strength indicator.