welded pipe, is a steel plate

　　Welded steel pipe, also known as welded pipe, is a steel plate or strip after the coil formed by the welding made of steel. Welding steel pipe production process is simple, the production efficiency is high, the variety specification is much, but the strength is lower than the seamless steel pipe.

　　Since the thirties of the 20th century, along with the rapid development of high quality cold rolling strip steel rolling production and progress of welding and inspection technology, weld quality rising, welding steel pipe specifications and more and more, and in more and more fields instead of the seamless steel pipe.

　　Product standards

　　Commonly used materials for welded pipe: Q235C Q235B, Q235A, 16Mn, 20#, Q345, etc. Welded pipe due to its different materials and usage, are divided into the following several standard: GB/T3091-2008 (low pressure fluid transport welded steel pipe). Mainly used for conveying water, gas, air, oil and heating hot water or steam and other generally low pressure fluid and other use pipe. Its representative material is: Q235A. GB/T14291-2006 (mineral fluid transport welded steel pipe). Mainly used in mine air pressure, drainage, gas drainage shaft with a straight seam welded steel pipe. Its representative material Q235A and Q234B.

　　production process

　　ERW production has the advantages of simple process, high production efficiency, low cost, rapid development. Strength of spiral welded pipe is usually better than straight seam welded pipe is high, can use a narrow diameter of billet production larger pipe can also differ with the same width of the billet production diameter pipe. Pipe process raw material uncoiling, leveling, end cutting and welding, looper, forming, welding - both inside and outside the weld bead removal -- pre correction - induction heat treatment, size and alignment: eddy current testing - cut -- check the water pressure, pickling, final inspection (strictly) -- packing, shipment.