Metal fusion bonding – Process – With shaping
Patent
1992-02-21
1993-03-09
Heinrich, Samuel M.
Metal fusion bonding
Process
With shaping
228158, 228223, 219 1053, 219 61, B23K 1302
Patent
active
051920166
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods for manufacturing tubes of carbon steel, stainless steel, copper alloy, aluminum alloy and other metals filled with a powdery and/or granular substance.
The powdery and granular substances are powders, granules or their mixtures, such as welding fluxes, oxide-based superconductors and steelmaking additives. This invention is used in the manufacture of wires containing welding fluxes, wires containing oxide-based superconductors and other tubes containing a powdery and/or granular substance.
2. Description of the Prior Art
Seamless wire containing welding flux is an example of tubes filled with a powdery and/or granular substance. The seamless wire is made by slitting steel strip into desired widths and gradually forming the slit strip formed into a U-shape, and then into an O-shape, using a series of forming rolls. Halfway in the forming process, a flux is fed from a feeder into the bottom of the U-shaped strip through an opening extending along the length thereof. When the U-shaped strip is formed into an O-shape, the meeting edges of the strip are welded together to close the opening. Then, the diameter of the welded shell is reduced. After being annealed as required, the tube filled with the flux is drawn into a wire of the desired diameter and coiled into the desired product form.
Low-frequency welding, high-frequency induction welding and high-frequency resistance welding are extensively used in the manufacture of tubes filled with a powdery and/or granular substance. In any of these welding methods, the edges of the strip fringing the opening are heated to the melting temperature by a low-frequency or high-frequency current and then pressed until they meet and form the weld by a pair of squeeze rolls.
The welded tubes filled with the flux may break in the subsequent process in which their diameter is reduced by rolling and drawing. This break is considered to result from the following cause. When welding is performed, some of the oxide or silicate in the flux adheres to the fringing edges of the opening in the formed tube. At the welding point, air flows outside from the formed tube through the opening as a result of the expansion caused by the collision of the air carried in by the approaching formed tube and the air flowing backward from the size-reducing point and by the heat of welding. The stream of air thus created blows up part of the flux, which adheres to the fringing edges of the opening in the formed tube. Some of the flux jumping up under the influence of the vibration of the approaching formed tube too adheres to the same area. Because of a magnetic field built up by the welding current at the welding point, in addition, the fringing edges of the formed tube serve as a magnetic pole. Therefore, the magnetic force of the fringing edges attracts the ferromagnetic ingredients of the flux. At this time, the ferromagnetic ingredients take some nonmagnetic components with them to the fringing edges. The flux thus adheres to the fringing edges fuses into the weld to form nonmetallic inclusions detrimental to the weld. This welding defect leads to cracking or breaking in the subsequent size reduction process.
The "Method and Apparatus for Manufacturing Filler Wire" disclosed in Japanese Provisional Patent Publication No. 234795 of 1985 offers a solution for this type of problem. This technology prevents the blow-up of the powder by drawing in the stream of air created in the formed tube upstream of the welding or roll-press zone. The "Method of Manufacturing Filler Wire" disclosed in the Japanese Provisional Patent Publication No. 234792 of 1985 offers another solution. This technology forms a lower layer a ferromagnetic or ferrite-based substance and an upper layer of a nonmagnetic substance so that the latter inhibits the attraction of the former to the fringing edges of the opening. The "Composite Welding Wire" disclosed in the Japanese Provisional Patent Publication No. 234794 of 1985 discloses a still a
REFERENCES:
patent: 4629110 (1986-12-01), Holmgren et al.
patent: 4673121 (1987-06-01), Holmgren
patent: 4811889 (1989-03-01), Dackus et al.
Araki Nobuo
Chatani Yoji
Fukui Takeshi
Hashimoto Seiji
Ishikawa Yasushi
Heinrich Samuel M.
Nippon Steel Corporation
Nippon Steel Welding Products & Engineering Co., Ltd.
LandOfFree
Methods for manufacturing tubes filled with powdery and granular does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods for manufacturing tubes filled with powdery and granular, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods for manufacturing tubes filled with powdery and granular will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-205952