在弯管机上弯制薄壁(壁厚0.5～l.0毫米)不锈钢管时,很容易产生“瘪”、“皱”等缺陷。上海长征机械厂摸索出一套液氮冷冻弯管工艺,并应用于生产。冷冻弯管就是将管子一端用橡皮塞堵住,灌满水后放入盛有液氮的双层(内抽真空)容器中,浸1小时左右,取出后擦洗外表面上的结霜,再放在弯管机上弯制成型。由于冻成的冰柱既“硬实”又“脆 Bending machines in the bending thin wall (wall thickness 0.5 ~ l.0 mm) stainless steel tube, it is easy to produce “deflated”, “wrinkles” and other defects. Shanghai Changzheng Machinery Factory worked out a set of liquid nitrogen frozen pipe technology and applied to the production. Frozen pipe is the end of the tube plugged with a rubber stopper, filled with water into the double-layer (vacuum) container filled with liquid nitrogen, dipped for about 1 hour, remove and scrub the outer surface of the frosting, and then On the bending machine bending forming. Because of the frozen icicles both “hard” and "crisp