Folds and internal cracks in medium and low pressure boiler tubes are the most common forms of defects. Internal folds and internal cracks may be distributed along the entire length of the steel pipe, or located only at both ends or part of the length. When rolling alloy steel pipes, inward folding is particularly easy to occur, and rolling general carbon steel pipes sometimes occur.
Read moreSpiral steel pipe is a spiral seam steel pipe made of strip steel coils as raw materials, often extruded and formed by automatic double-wire double-sided submerged arc welding.
Read moreThe rapid cooling of steel pipes after rolling has obvious effects on the production of bearing steel pipes, reducing network carbides, improving the pearlite structure, and shortening the spheroidizing annealing time.
Read moreThe forming technologies of large-size seamless pipe fittings mainly include: hot spinning, hot extrusion, hot piercing and rolling, and hot pushing and expanding.
Read moreThis method includes the setting of the furnace temperature and holding time in two passes.
Read moreThe temperature conditions of the two experiments are basically the same, but the length and force of the weld are different. In the bending test, the weld is located on the side of the main surface of the bend, while in the flattening test, the weld is perpendicular to the direction of load application.
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