Electric heating – Metal heating – Nonatmospheric environment at hot spot
Reexamination Certificate
1998-07-28
2002-08-27
Elve, M. Alexander (Department: 1725)
Electric heating
Metal heating
Nonatmospheric environment at hot spot
C219S072000, C219S146100, C219S146230
Reexamination Certificate
active
06441334
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a welding wire containing flux used for a gas shielded arc welding of a direct current positive polarity mode with polarity arrangement that the welding wire is biased as a negative electrode and a mother material is biased as a positive electrode. More particularly, the present invention relates to a gas shielded arc welding flux cored wire, with use of which a quantity of sputter generated is small, a good weldability (bead forming inclination) is realized and a weld metal with an excellent toughness is obtained in all the welding positions such as not only a flat welding position but a vertical welding position and the like under application of a welding current in the range of a low current to a medium current, or in a definite manner in the range of 50 to 300 A.
2. Related Prior Art
The applicant has proposed a barium fluoride based flux cored wire, which is added with BaF
2
as a fluoride for the purpose to decrease a quantity of sputter by stabilizing arc (Publication of Unexamined Japanese Patent Application No. Hei. 2-55696). The barium fluoride based flux cored wire is used in a direct current positive polarity mode, where a direct current is used in arc welding and a wire is biased as a negative electrode (a mother material is a positive electrode). In the case of this direct current positive polarity mode, a melt drop at the tip end of the wire receives not only an impact force caused by a positive ion but a large reactive force caused by evaporation of BaF
2
and the like having a high vapor pressure, so that the melt drop at the tip end of the wire is transformed into smaller melt particles by the result of those forces, whereby a smooth transfer to the mother material is realized. Thus, stabilization of arc and reduction in a quantity of sputter is achieved.
The conventional gas shielded arc welding flux cored wire of a direct current positive polarity mode, which has been proposed, has a feature that the wire comprises BaF
2
, Al, Mg, Fe, Mn and Si as indispensable components and a quantity of sputter generated is small under application of a low welding current in the range of 100 to 200 A.
However, with the conventional wire in use, there have been problems to be solved, which are 1) reduction in a quantity of sputter, 2) improvement on weldability (ability to realize good shaped bead formation) and 3) improvement on toughness of a weld metal, in all the positions such as a vertical position, a horizontal position, an overhead position, in which molten metal is subject to hanging-down by an influence of the gravitational force, under application of a welding current in the range of a low current to a medium current, or in a definite manner in the range of 50 to 300 A.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to provide a gas shielded arc welding flux cored wire used in a direct current positive polarity mode, with use of which a quantity of sputter generated is small, a good weldability is realized and a weld metal with an excellent toughness is obtained in all the welding positions such as a flat welding position, an overhead welding position and the like under application of a welding current in the range of a low current to a medium current, or in a definite manner in the range of 50 to 300 A.
A first aspect of the present invention is directed to a gas shielded arc welding flux cored wire used in a direct current positive polarity mode, comprising: a steel sheath; and flux with which the steel sheath is filled, wherein the flux contains 0.7 to 3 wt % Al, 0.1 to 1.2 wt % Mg and 1.2 to 5 wt % BaF
2
, each content being a value in wt % to a total weight of the wire and the sum of a content of Al plus a content of Mg multiplied by 3 being in the range of 1.3 to 5 wt %, a filling ratio of the flux to the total weight of the wire is in the range of 5 to 30 wt %, a total Mn content in the steel sheath and the flux combined is in the range of 0.2 to 1.9 wt % and a total Si content in the steel sheath and the flux combined in the range of 0.001 to 0.9 wt %.
A second aspect of the present invention is directed to a gas shielded arc flux cored wire used in a direct current positive polarity mode, comprising: a steel sheath; and flux with which the steel sheath is filled, wherein the flux contains 0.9 to 2.5 wt % Al, 0.1 to 0.8 wt % Mg and 1.2 to 4 wt % BaF
2
, each content being a value in wt % to a total weight of the wire and the sum of a content of Al plus a content of Mg multiplied by 3 being in the range of 1.6 to 4 wt %, a filling ratio of the flux to the total weight of the wire is in the range of 7 to 20 wt %, a total Mn content in the steel sheath and the flux combined is in the range of 0.4 to 1.6 wt %, a total Si content in the steel sheath and the flux combined in the range of 0.001 to 0.6 wt %, a total C content in the steel sheath and the flux combined in the range of 0.005 to 0.08 wt %, wherein a ratio of the austenite forming elements to the ferrite forming elements X=(4Ni+7Mn+20C)/(2Al+Si)≧0.7, wherein the atomic symbols indicating respective contents of the corresponding elements, and a content of oxygen in a weld metal from the wire is 200 ppm or less.
A third aspect of the present invention is directed to a gas shielded arc flux cored wire used in a direct current positive polarity mode according to any one of the first and second aspects, wherein the flux further contains 0.1 to 3 wt % Ni, the weight % being to the total weight of the wire.
A fourth aspect of the present invention is directed to a gas shielded arc flux cored wire used in a direct current positive polarity mode according to any one of the first to third aspects, wherein the flux further contains 1.5 wt % or less oxides, the weight % being to the total weight of the wire.
With a flux cored wire used in gas shielded arc welding of a direct current positive polarity mode pertaining to the present invention having the above described constitution, a quantity of sputter generated is small, and not only is good weldability realized but a weld metal with an excellent toughness can also be obtained in all the welding positions such as a flat welding position, an overhead welding position and the like can also be attained under application of a welding current in the range of 50 to 300 A, that is in the range of a low current to a medium current.
REFERENCES:
patent: 3947655 (1976-03-01), Gonzalez et al.
patent: 4343984 (1982-08-01), Smith et al.
patent: 4366364 (1982-12-01), Arai et al.
patent: 4571480 (1986-02-01), Sakai et al.
patent: 5580475 (1996-12-01), Sakai et al.
patent: 0 231 570 (1987-08-01), None
patent: 2 270 982 (1975-12-01), None
patent: 2-055696 (1990-02-01), None
patent: 5-329684 (1993-12-01), None
patent: 6-155079 (1994-06-01), None
patent: 9-094665 (1997-04-01), None
patent: 9-094695 (1997-04-01), None
patent: 9-285891 (1997-11-01), None
Patent Abstracts of Japan, vol. 14, No. 224 (M-0972), May 11, 1990, JP 2-055696, Feb. 26, 1990.
Aida Isao
Koshiishi Fusaki
Kurokawa Tsuyoshi
Suga Tetsuo
Uchiyama Hajime
Elve M. Alexander
Kabushiki Kaisha Kobe Seiko Sho
LandOfFree
Gas shielded arc welding flux cored wire does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gas shielded arc welding flux cored wire, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gas shielded arc welding flux cored wire will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2922495