Cold-rolled seamless steel pipe, also known as cold-drawn seamless steel pipe, and its process are: round tube → heating → perforation → start → annealing → pickling → oiled (copper) → Multi-pass cold drawing → blank → heat treatment → straightening → hydrostatic test (flaw detection) → mark → storage. Cold drawn (rolled) seamless steel pipe rolling method than hot-rolled (extruded seamless steel pipe) complex. The first three steps of their production process is basically the same. The difference from the fourth step, the round tube blank after the blow, to start, anneal. After annealing with a special acid liquid pickling. Pickled, oiled. Then followed by a multi-pass cold drawing (cold rolling) and then pipe, special heat treatment. After heat treatment, it should be straightened. Steel straightening by the conveyor belt to the metal detector (or water pressure test) for internal testing. If there are cracks inside the steel pipe, bubbles and other issues, will be detected. Pipe quality inspection but also through a rigorous manual selection. Pipe quality inspection, spray paint on the number, size, production lot number, etc., and hoisted by the crane in the warehouse.
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Post time: Dec-06-2017