Varför är rak sömstålröret det första valet för olje- och gastransport?
Straight seam steel pipe has become the first choice for long-distance pipelines because of its high weld strength and good pressure bearing capacity (X80 steel grade can reach more than 15MPa). Compared with spiral welded pipes, its welds are short and the probability of defects is low. Steel pipes certified by API 5L PSL2 can meet the requirements of acidic environments. In addition, the geometric dimension accuracy of straight seam pipes is higher, which is convenient for on-site butt welding. In projects such as the "West-East Gas Transmission", straight seam submerged arc welded pipes (LSAW) account for more than 70%.
Hur väljer jag raka sömmarna i byggnadsstrukturer?
Q355B straight seam welded pipes are commonly used in building steel structures. Their yield strength is>=355MPa and they have excellent seismic performance. Square and rectangular pipes are mostly used for columns and beams. After cold bending, they need to be annealed to eliminate stress. In high-rise Byggnader, tjockväggade raka sömrör med stor diameter (såsom φ1200 × 30 mm) kan användas som kärnrörsstöd . Brandhämmande beläggningar och galvanisering är standard antikorrosionsmått för att bygga rör .}
Särskilda krav för stålledningar i raka sömmar i vattenbevaringsprojekt?
Water conservancy projects require steel pipes to be resistant to sediment erosion and microbial corrosion, and the inner wall is often sprayed with epoxy coal tar or lined with cement mortar. Pressure pipes must pass the GB/T 3091 water pressure test, and Q235B material is selected when the working pressure is<=2.5MPa. Steel Rör för vattenledningstunnlar måste beakta negativa tryckförhållanden, och ringstyvheten måste vara större än eller lika med 8kn/m².
Varför använder biltillverkare tunnväggiga raka sömmar svetsade rör?
The wall thickness of straight seam pipes for automobile chassis and exhaust systems is only 1.5-3mm, and the ERW process is used to ensure the flatness of the weld. The materials are mostly 409L stainless steel (resistant to high temperature oxidation) or DP600 duplex steel (30% weight reduction). The dimensional tolerance must be controlled within ± 0 . 1mm för att undvika monteringsstörningar . Lasersvetsade rör har använts i nya energibatteriets strukturella delar.
Vilka är begränsningarna för raka sömmarör i kemisk utrustning?
Although 316L straight seam pipe is acid and alkali resistant, Hastelloy C276 must be used in hydrofluoric acid working conditions. High-pressure reactors need to be forged as a whole, because the hoop stress of straight seam pipes is only 80% of that of seamless pipes. When the temperature exceeds 450℃, TP347H austenitic stainless steel must användas och lösning behandlas .
