GB655532A - Improvements in or relating to the production of seamless steel tubes - Google Patents

Abstract

655,532. Making seamless tubes. WELLMAN SMITH OWEN ENGINEERING CORPORATION, Ltd., and BROOKS, C. Dec. 1, 1948, No. 31168. [Classes 83 (ii) and 83 (iv)] In a method of producing seamless steel tubes, a cast or rolled billet is placed in a hollow container of a piercing press. and is pierced by means of a punch which has a diameter greater than that of the mandrel employed in the push bench apparatus or continuous seamless tube mill, the bottle thus formed, before having the mandrel applied to it, is subjected to a rolling operation which reduces its internal diameter to, or approximately to, the diameter of the mandrel, and the bottle, after having the mandrel applied to it, is passed through the ring or roller dies or grooved rolls of the push bench apparatus or seamless tube mill. Apparatus for carrying out the above method comprises a piercing press 1, a skew roll mill 10 constructed to reduce the internal diameter of the bottle to, or approximately to, the diameter of the mandrel 40 of a push bench apparatus 38 or a continuous seamless tube mill, Fig. 2 (not shown). Billet-piercing.-The piercing press 1 comprises a hollow container 2 into which the billet is placed, 'the billet being pierced by means of a hydraulically-operated punch 3 of greater diameter than that of the mandrel 40 and the bottle 12 thus formed is ejected by means of a hydraulically-operated pusher 5. Rolling.-The skew roll mill 10 comprises inclined driven rolls 11 arranged so that when the bottle 12 has placed in it a hydraulicallyoperated mandrel 13 of a diameter the same as, or slightly larger than, that of the mandrel 40 and is fed to the rolls it is closed on to the mandrel and spread out lengthwise thereon in the form of a closed-ended bottle. Separating mandrels from work.-The bottle and mandrel 13 after being passed through the mill 10 are conveyed to a mandrel extractor apparatus 22 comprising a device 29 for gripping the mandrel and a step 30 against which the bottle engages on the withdrawal of the mandrel. The device 29 is carried by a bogie 27 running on rails 28 and connected to a motor-driven endless chain 23. The extracted mandrels are conveyed back to the front of the mill 10 for re-use. The push bench apparatus comprises similar mandrel extractor apparatus 50. Cupping.-The bottle after having the mandrel 13 extracted therefrom is conveyed to a table 36 of the push bench apparatus 38 comprising a mandrel 40 which is fed forward to the bottle which is then pushed through a series of dies 37 to form a tube. A table 45 conveys the tube to a polishing or reeling apparatus 46 which loosens the tube on its mandrel 40. The tube is then conveyed to the mandrel extractor apparatus 50. The extracted mandrels are conveyed back through a furnace 53 to the front of the table 36 for reuse. The tube freed from the mandrel passes to hot saw and finishing apparatus 57. When the push bench apparatus is replaced by a continuous seamless tube mill, Fig. 2 (not shown), the dies 37 are replaced by grooved rolls.