Spiral submerged arc pipe for liquid transportation: water supply and drainage. For gas transportation: gas, steam, liquefied petroleum gas. For structural use: for piling pipes, for bridges; for piers, roads, building structures, etc. Mainly used in water supply engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, urban construction, is the 20 key points developed in China One of the products. There are several kinds of fractures of spiral steel pipes. According to the situation after the material is destroyed, the fractures of the anti-corrosion steel pipes and the metal materials are roughly divided into three types, namely: 1 cleavage fracture, 2 dam hole reverse fracture, 3 slip surface Separation fracture. Among them, 7, 5 are shear fractures.

The cross-section of the cleavage fracture is strictly separated along a certain aspect of the crystal, which is called the cleavage plane. When breaking along this crystal plane, the theoretical rupture strength is the lowest and is determined by the formula (1-4). The factor that determines the cleavage plane is the surface energy y, the surface spacing of the crystal plane and the elastic modulus along the normal direction. The cleavage fracture is almost accompanied by plastic deformation, which is a brittle fracture, which occurs in the body-centered cubic and densely packed hexagonal gold. Face-centered cubic metals generally do not undergo cleavage fracture. For the gold phase of the nature of the ductile material, shear fracture is the main fracture mechanism. For example, the second phase particles in the anti-corrosion steel tube alloy hinder the slippage and increase the resistance to plastic deformation; when the plastic deformation increases, the second phase particles and the matrix interface are peeled off to produce micro-holes; Forming, growing and combining form a shear section.

For high-purity metals, the bimetallic wear-resistant composite steel pipe is not produced because of the absence of the second phase particles. The micro-holes are produced, and the surface area is increased only as a result of the migration. Finally, the cross-section of the slip surface is formed. Anti-corrosion steel pipe spinning composite technology is under the precise control of special equipment. The friction roller rotates with the inner liner to generate heat energy, which quickly reaches the softening point of stainless steel. The pressure roller is pressed outward to make the outer tube elastically deform. Cooperate to achieve close integration. From the perspective of the gold histology, the fracture is divided into transgranular fracture and fracture along the product.

Three kinds of fracture hungry of the above anti-corrosion steel pipes are likely to occur. For the destruction of actual materials, depending on the material or external conditions, one of the three fracture mechanisms will play a leading role, but in the case of the ship, they should be present at the same time.

Confined fluid transport, using spiral submerged arc welded steel pipe SY5036-2000, mainly used to transport oil and natural gas pipelines;
Spiral seam high-frequency welded steel pipe SY5038-2000 for pressure fluid conveying, spiral high-frequency welded steel pipe for high-pressure lap welding. The steel pipe has strong pressure bearing capacity and good plasticity, which is convenient for welding and processing;

General low-pressure fluid transportation, submerged arc welded steel pipe for general low-pressure fluid transportation such as water, gas, air and steam, which is made by double-sided automatic submerged arc welding or single-side welding using spiral submerged arc welded steel pipe SY5037-2000. Commonly used standards for spiral steel pipes are generally divided into: SY/T5037-2008 (partial standard, also called spiral seam submerged arc welded pipe for ordinary fluid conveying pipeline), GB/T9711.1-2008 (national standard, also called oil and gas industry conveying steel pipe Technical conditions of the goods Part I:
Class A steel pipe (strictly required GB/T9711.2 Class B steel pipe)), API 5L (American Petroleum Institute, also called pipeline steel pipe; which is divided into two levels of PSL1 and PSL2), SY/ T5040-2008 (spiral welded steel pipe for piles). SY/T5037-2008 is the standard set by the Ministry of Petroleum. GB/T9711.1-2008 national spiral pipe, oil and gas industry conveying steel pipe, class A general low pressure fluid conveying spiral seam high frequency welded steel pipe (SY5039-2000) is hot rolled steel strip coil for tube blank, regular temperature spiral forming It is welded by high frequency lap welding method for erw steel pipe for general low pressure fluid transportation.