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US4400611A Expired / Lapsed US ⏱️ 0.0 years remaining

Welding at pressures greater than atmospheric pressure

Assignee: Welding Institute England
•
Filing: 1980-11-14
•
Granted: 1983-08-23
•
Expires: 2000-11-14
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Abstract

Abstract When metal inert gas (MIG) welding is carried out at normal atmospheric pressure, the electrode is made positive with respect to the workpiece because the use of a negative electrode gives little penetration. In undersea welding, as the pressure increases the arc stability and metal transfer in MIG welding become erratic and there is copious fume evolution. According to the present invention, MIG welding at pressures greater than 7 bars is carried out with the electrode negative with respect to the workpiece and with an electrode wire of diameter not greater than 1.4 mm; the slope of the power supply, as seen from the welding arc, is preferably between 6 and 15 V/100 A, which is higher than the 3 to 4 V/100 A used in positive-electrode MIG welding at normal atmospheric pressure.

Inventors

  • 👤 Michael E. Wilkinson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 03:19
CPC Classifications
H; H01; H01R; H01R13/00; H01R13/44; H01R13/447; H01R33/00; H01R33/05; H01R33/46

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 124 words
A welding method comprising connecting a solid uncoated consumable electrode wire, having a diameter not greater than 1.4 mm, and workpiece to opposite poles of an electrical power supply having a slope, as seen from the welding arc, of between (6-15) V/100 A to form an arc between the electrode and the workpiece and thereby to transfer metal from the electrode to the workpiece, providing an inert gas shield around the arc at the workpiece, and advancing the electrode towards the workpiece at a rate which matches the consumption of the electrode; and further comprising carrying out the welding method at a pressure of at least 7 bars and connecting the power supply so that the electrode is negative with respect to the workpiece.
Claim 2
Dependent Claim 124 words
A welding method comprising connecting a solid uncoated consumable electrode wire, having a diameter not greater than 1.4 mm, and workpiece to opposite poles of an electrical power supply having a slope, as seen from the welding arc, of between (6-15) V/100 A to form an arc between the electrode and the workpiece and thereby to transfer metal from the electrode to the workpiece, providing an inert gas shield around the arc at the workpiece, and advancing the electrode towards the workpiece at a rate which matches the consumption of the electrode; and further comprising carrying out the welding method at a pressure of at least 7 bars and connecting the power supply so that the electrode is negative with respect to the workpiece.
Claim 3
Dependent Claim 16 words
A method in accordance with claim 1, carried out at a pressure greater than 10 bars.
Claim 4
Dependent Claim 23 words
A method in accordance with claim 1 or 2, in which the diameter of the electrode wire is not greater than 1.0 mm.
Claim 5
Dependent Claim 57 words
A method in accordance with claim 1, in which the welding is carried out on the seabed and in which the power source is carried on a surface vessel, the slope of the power supply,including the power source and a cable connecting the power source to a welding head on the seabed, lying within the said range.
Claim 6
Dependent Claim 17 words
A method in accordance with claim 1 or 5, in which the inert gas is predominantly argon.

References Cited (Backward Citations)

US4035602A Cited
US3969603A Cited
US4052632A Cited
US4154999A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-08-22 1987-02-21 1987-08-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-08-22 1991-02-21 1991-08-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-08-22 1995-02-21 1995-08-23 $7700.00 Window Closed / Lapsed

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