Electric heating – Metal heating – Cutting or disintegrating
Patent
1997-04-15
1999-06-29
Evans, Geoffrey S.
Electric heating
Metal heating
Cutting or disintegrating
219105, B23H 106, B23H 708
Patent
active
059164573
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a material to be welded for butt welding, a method of cutting the same, a method of welding the same, a wire used for electric discharge machining, a fluid supply piping system, and a process device.
TECHNOLOGICAL BACKGROUND
(A) In association with the tendency for higher degree of integration and higher performance in the field of semiconductor devices, there are demands for a manufacturing device which can satisfy the needs, there have been made intensive efforts for creating a higher degree of vacuum and cleaner atmosphere for forming a film.
In order to create an ultra-high degree of vacuum and ultra-clean atmosphere for forming a film, it is required to completely suppress out gas discharged from the manufacturing device (e.g., a process device for forming films or the like) as well as from the internal surface of a fluid supply piping system for gas or the like.
With years of research and development activities by the present inventor, now it is possible to form an oxide passivated-film on a surface of the device or the like containing therein chromium oxide as a main element which is excellent in corrosion resistance and emits only an extremely small amount of out gas therefrom. As a result, the present inventor has succeeded in creating a supply gas as well as an atmosphere for forming a film in which out gas discharged from inside of the device is suppressed to a rate so that the gas is hardly detected by any of current measuring devices. Namely, it is possible to suppress a density of impurities (moisture, hydrocarbons or the like) in the supply gas as well as in the atmosphere for forming a film to not more than the order of ppb and further to the order of ppt.
However, in accordance with the tendency that devices become increasingly larger in size and more complicated, there have been more and more intense needs for constructing a fluid piping for gas, chemicals or the like as well as a manufacturing device for a semiconductor or the like with materials to be welded each having an oxide passivated-film with chromium oxide as a main element thereof formed thereon made by cutting a long-sized member having an oxide passivated-film with chromium oxide as a main element thereof formed thereon to a specified length, and by connecting the materials to be welded to each other by welding.
It should be noted that conventionally the member is cut with a manual pipe cutter. Then, after the material is cut, the cut edge faces are further smoothed with bite by a specific edge-face processing device (produced by Tritool) to remote burrs due to the cutting, and also the roughness of the surface is made to be fine.
The cutting and the smoothing are executed while inert gas such as N.sub.2 gas or the like as purge gas is flown onto the surfaces being cut to prevent deposition of particles from outside as well as of chips generated when the material is cut onto the surfaces of the material to be welded. Especially, in a case where the material to be welded is tubular, particles from outside as well as chips generated when the material or the like is cut go into inside of the pipe and are deposited on the internal surface of the pipe, so that it is especially required that the cutting is executed while purge gas is flown inside the pipe.
(B) On the other hand, even if careful attention is paid to the matter generated when the material is cut, the oxide passivated-film is eliminated when the materials are welded, so that the surface of a welded bead section is not covered with the oxide passivated-film. For this reason, gas is easily deposited on and removed from the welded bead section, which causes the supply gas to be contaminated. Further, in not only the bead section but also in both sides of the welded bead section, chromium is volatilized, whereby chromium composition therein abruptly decreases, so that the corrosion resistance is reduced, which is the fact found by the present inventor. FIG. 1 shows the state as described above, and in the figure
REFERENCES:
patent: 3722778 (1973-03-01), Rohrberg et al.
patent: 3912151 (1975-10-01), Martin
patent: 4484060 (1984-11-01), Frye
patent: 5152059 (1992-10-01), Midgley
patent: 5243167 (1993-09-01), Lundquist et al.
patent: 5396039 (1995-03-01), Chevrel et al.
patent: 5580398 (1996-12-01), Ohmi
patent: 5667133 (1997-09-01), Ohmi et al.
Evans Geoffrey S.
Knuth Randall J.
LandOfFree
Material to be welded for butt welding, methods of cutting as we does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Material to be welded for butt welding, methods of cutting as we, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Material to be welded for butt welding, methods of cutting as we will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1373216