DIN 14mm Welded ERW Steel Pipe Hydrostatic Test

Hydrostatic Test High Frequency Welded Pipe Water Engineering ERW Steel Pipe

The high frequency welding thermal process of ERW steel tube results in the gradient of temperature distribution near the edge of the tube blank, and forms the characteristic areas such as melting zone, semi-melting zone, superheated structure, normalizing zone, incomplete normalizing zone and refiring zone.Among them, the austenite grains in the overheated area grow rapidly due to the welding temperature above 1000℃, and the hard and brittle coarse grain phase will be formed under the cooling condition.

The welding is pressure bonding rather than molten welding. Compared with molten welding, the welding heat affected area is relatively small and has little influence on the microstructure of the base material. After welding, the strength and toughness of the weld are different from that of the parent. According to the use of the material, the internal and external welding burrs can be cleaned or not.

Welding to the work piece can not be cleaned, can be welded thin wall pipe, welding metal pipe.For liquid transport: water supply, drainage. For gas transmission: gas, steam, liquefied petroleum gas. For structural use: as pile driving pipe, as bridge; Pipes for wharves, roads, building structures, etc. High-frequency straight seam welded steel tube process: longitudinal shear -- uncoiling -- strip flattening -- head and tail shear -- strip butt welding -- sleeve storage -- forming -- welding -- removing burrs -- sizing -- flaw detection -- flying cut -- initial inspection -- straightening of steel tubes -- pipe section processing -- hydrostatic test -- flaw detection -- printing and coating -- finished products. High frequency straight seam welded steel pipe is mainly used in water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, urban construction.