Welding process
AssigneeTenneco Inc.
InventorDonald P. Worden
Life of this patent
Estimating the term…
Abstract
An internal spreader bar provides control of the convergence point and convergence angle of opposite electrically heated edges of a skelp during a tube seam welding operation and other controls are practiced to increase weld pressure at the faying surfaces.
Claims33
A method of continuously welding together to form a seam the abutting edges of metal which comprises continuously moving the metal longitudinally in one direction, heating the edges to be welded together, passing the heated edges through squeeze roll means to apply welding pressure to the edges, and separating the edges in advance of the weld line defined by the squeeze roll means to maintain them out of pressure contact with each other until they reach a point approximately 1 to 3 metal thicknesses in advance of said weld line.
A method of making metal tubing which comprises continuously passing a skelp having heated edges separated by a gap through welding pressure roll means to fuse the edges together while maintaining the edges out of pressure contact until they reach a point approximately 1 to 3 metal thicknesses in advance of the line of maximum pressure applied by the roll means.
The method of making stainless steel tubing or the like which comprises forming a skelp having a longitudinally extending gap between opposite edges, heating said edges to welding temperature by application of high frequency electrical current along a length extending in advance of a weld line, and applying pressure to said edges to fuse them together in a welded joint while separating said edges in advance of said weld line so that pressure is applied to them for a length of no more than approximately three metal thicknesses in advance of said weld line.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, high frequency electrical means for heating the edges of the skelp to be welded together, pressure rollers positioned on opposite sides of said path to apply welding pressure along a weld line to skelp entering the rollers, and spreader means fixedly positioned inside of the skelp and effective on the skelp to maintain separation of the edges to be welded until such edges have advanced to no more than approximately three times metal thickness from said weld line.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, means for heating the edges of the skelp to be fused at a high temperature gradient for rendering a shallow depth of said edges in a fusible state, pressure applying means positioned on opposite sides of said path to apply welding pressure along a weld line to the skelp entering said pressure applying means, and spreader means for controlling the angle and point of contact of said edges, said spreader means being fixedly positioned adjacent the skelp and a predetermined position remote from the point of contact of the edges and effectively contacting opposite sides of the interior surface of the skelp along a line substantially parallel to the width of the gap separating the edges to maintain separation of the edges to be welded until such edges have advanced to a predetermined distance ahead of but close to said weld line.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, high frequency electrical means for heating the edges of the skelp to be welded together, pressure applying means positioned on opposite sides of said path to apply welding pressure along a weld line to skelp entering said pressure applying means, and spreader means fixedly positioned inside of the skelp and effectively contacting the interior surface of the skelp to maintain separation of the edges to be welded until such edges have advanced to a predetermined distance ahead of but close to said weld line, said spreader means comprising a member substantially coaxial with the skelp and a pair of nonmagnetic pads supported on the member in surface contact with the inside of said skelp to apply pressure thereto to maintain separation of the edges substantially along a diameter of the skelp that is normal to a diameter intersecting the space between said edges.
The method of making tubing from A.I.S.I. 409 stainless steel comprising forming a skelp having a longitudinally extending V-shaped gap between the opposite edges to be welded together to form a seam, heating said edges to welding temperature along a length extending in advance of a weld line by applying high frequency electrical current to said edges, applying welding pressure to said edges to weld them together into a welded seam, said pressure being a maximum along said weld line, applying welding pressure sufficient in magnitude to produce reduction in circumference of 0.045 to 0.085 inch in said A.I.S.I. 409 tubing of 2 inch outer diameter and 0.040 to 0.060 inch wall thickness, and applying internal spreading pressure to the inner surface of said skelp to maintain a substantially predetermined angle for said V-shaped gap and to maintain said opposite edges out of contact until a predetermined point ahead of said weld line.
The method of making tubing from A.I.S.I. 409 stainless steel comprising forming a skelp having a longitudinally extending V-shaped gap between the opposite edges to be welded together to form a seam, heating said edges to welding temperature along a length extending in advance of a weld line by applying high frequency electrical current to said edges, applying welding pressure to said edges to weld them together into a welded seam, said pressure being a maximum along said weld line, and applying internal spreading pressure to the inner surface of said skelp to maintain a substantially predetermined angle for said V-shaped gap and to maintain said opposite edges out of contact until a predetermined point ahead of said weld line, the length of edges heated to welding temperature being substantially within the range of 1.00 to 1.25 inch .
The method of making tubing comprising forming a skelp having a longitudinally extending V-shaped gap between the opposite edges to be welded together to form a seam, heating said edges to welding temperature along a length extending in advance of a weld line by applying high frequency electrical current to said edges, applying welding pressure to said edges to weld them together into a welded seam, said pressure being a maximum along said weld line, and applying internal spreading pressure to the inner surface of said skelp to maintain a substantially predetermined angle of no less than 4.degree. for said V-shaped gap and to maintain said opposite edges out of contact until a predetermined point ahead of said weld line.
The method of making alloy steel tubing comprising forming a skelp having a longitudinally extending V-shaped gap between the opposite edges to be welded together to form a seam, heating said edges to welding temperature along a length extending in advance of a weld line by applying high frequency electrical current to said edges, applying welding pressure to said edges to weld them together into a welded seam, said pressure being a maximum along said weld line, and applying internal spreading pressure to the inner surface of said skelp to maintain a substantially predetermined angle for said V-shaped gap and to maintain said opposite edges out of contact until a predetermined point ahead of said weld line, said predetermined point being no more than three times the metal thickness.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, high frequency electrical means for heating the edges of the skelp to be welded together, pressure applying means positioned on opposite sides of said path to apply welding pressure along a weld line to skelp entering said pressure applying means, and spreader means fixedly positioned inside of the skelp and effectively contacting opposite sides of a wide portion of the interior surface of the skelp spaced a substantial distance from said edges to maintain separation of the edges to be welded until such edges have advanced to a predetermined distance ahead of but close to said weld line, said spreader means comprising a member substantially coaxial with the skelp and a pair of non-magnetic pads supported on the member in surface contact with the inside of said skelp to apply pressure thereto to maintain separation of the edges substantially along a diameter of the skelp that is normal to a diameter intersecting the space between said edges.
The method of making alloy steel tubing comprising forming a skelp having a longitudinally extending V-shaped gap between the opposite edges to be welded together to form a seam, heating a shallow depth only of said edges at a high temperature gradient to welding temperature along a length extending for a short length in advance of a weld line by applying high frequency electrical current to said edges, applying welding pressure to said edges to weld them together into a welded seam, said pressure being a maximum along said weld line, and applying internal spreading pressure to a wide portion of the inner surface of said skelp along a transverse line spaced a substantial distance inwardly from said edges and substantially parallel to the width of the gap to maintain a substantially predetermined angle of convergence for said V-shaped gap and to maintain said opposite edges out of contact until a predetermined point ahead of said weld line.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, means for heating the edges of the skelp to be fused at a high temperature gradient for rendering a shallow depth of said edges in a fusible state, pressure applying means positioned on opposite sides of said path to apply welding pressure along a weld line to the skelp entering said pressure applying means, and separator means for controlling the angle and point of contact of said edges, said separator means being fixedly positioned adjacent the skelp and a predetermined position remote from the point of contact of the edges and effective to apply outward spreading pressure on the interior surface of the skelp substantially along a transverse line spaced a substantial distance inwardly from said edges and substantially parallel to the width of the space between the edges to maintain separation of the edges to be welded until such edges have advanced to a preestablished distance ahead of but close to said weld line.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, high frequency electrical means for heating at a high temperature gradient only a shallow depth of the edges of the skelp to be welded together, pressure applying means positioned on opposite sides of said path to apply welding pressure along a weld line to skelp entering said pressure applying means, and tapered separator means mounted inside the skelp and providing a spreader surface operating against the interior surface of the skelp and effective to apply outward spreading pressure to the skelp to maintain separation of the edges to be welded until such edges have advanced along said path to a position close to said weld line, said spreader surface being tapered on an effective predetermined angle and providing means to maintain an angle of convergence between said edges of said predetermined angle.
The method of making alloy steel tubing comprising forming a skelp having a longitudinally extending V-shaped gap between the opposite edges to be welded together to form a seam, heating a shallow depth of said edges at a high temperature gradient to welding temperature along a short length extending in advance of a weld line by applying high frequency electrical current to said edges, applying very high welding pressure to said heated edges to break through barrier layers of oxides and to weld them together into a welded seam, said pressure being a maximum along said weld line, applying a jet of oxide inhibiting gas to said gap at a point spaced ahead of said weld line, and applying internal spreading pressure to a wide portion of the inner surface of said skelp along a transverse line spaced a substantial distance inwardly from said edges and substantially parallel to the width of the gap to maintain a substantially predetermined angle of convergence for said V-shaped gap and to maintain said opposite edges out of contact until a predetermined point close to and ahead of said weld line.
The method of making metal tubing comprising forming a skelp having a longitudinally extending V-shaped gap between the opposite edges to be welded together to form a seam, heating said opposite edges to welding temperature by application thereto of high frequency electrical current along a length in advance of a weld line, applying welding pressure which is substantially at a maximum along said weld line to said edges to weld them together into a welded seam, and separating said edges in advance of said weld line to maintain said opposite edges out of contact until they reach a point approximately 1 to 3 metal thicknesses in advance of said weld line.
The method of making metal tubing comprising forming a skelp having a longitudinally extending V-shaped gap between the opposite edges to be welded together to form a seam, heating said opposite edges to welding temperature by application thereto of high frequency electrical current along a length in advance of a weld line, applying welding pressure which is substantially at a maximum along said weld line to said edges to weld them together into a welded seam, and separating said edges in advance of said weld line to maintain said opposite edges out of contact until they reach a point approximately 1 to 3 metal thicknesses in advance of said weld line and to maintain an angle of no less than 4.degree. for said V-shaped gap.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, high frequency electrical means for heating the edges of the skelp to be welded together, pressure means positioned on opposite sides of said path to apply welding pressure along a weld line to skelp entering the pressure means, and edge separation means positioned in advance of said weld line and effective on the skelp to maintain separation of the edges to be welded so that they are out of contact until such edges have advanced to a point no more than approximately three times the metal thickness in advance of said weld line.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, high frequency electrical means for heating the edges of the skelp to be welded together, pressure means positioned on opposite sides of said path to apply welding pressure along a weld line to skelp entering the pressure means, and edge separation means positioned in advance of said weld line and effective on the skelp to maintain separation of the edges to be welded so that they are out of contact until such edges have advanced to a point no more than approximately three times the metal thickness in advance of said weld line and to maintain an angle of convergence of at least 4.degree. between said edges to be welded.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, high frequency electrical means for heating the edges of the skelp to be welded together, pressure applying means positioned on opposite sides of said path to apply welding pressure along a weld line to skelp entering said pressure applying means, and separator means fixedly positioned inside of the skelp and effective to apply outward spreading pressure on the interior surface of the skelp substantially along a transverse line spaced a substantial distance inwardly from said edges and substantially parallel to the width of the space between the edges to maintain separation of the edges to be welded until such edges have advanced to a preestablished distance ahead of but close to said weld line, said separator means being tapered on an effective angle of about 5.degree. and providing means acting on the interior surface of the skelp to maintain an angle of convergence of about 5.degree. between said edges.
In a tube mill for making tubing by forming a skelp from strip metal and welding the edges of the skelp together, the combination of means for continuously moving the skelp along a path extending longitudinally of the length of the tubing being formed, high frequency electrical means for heating the edges of the skelp to be welded together, pressure applying means positioned on opposite sides of said path to apply welding pressure along a weld line to skelp entering said pressure applying means, and tapered separator means mounted inside the skelp and providing a spreader surface operating against the interior surface of the skelp and effective to apply outward spreading pressure to the skelp to maintain separation of the edges to be welded until such edges have advanced along said path to a position close to said weld line, said spreader surface being tapered on an effective predetermined angle of approximately 5.degree. and providing means to maintain an angle of convergence between said edges of said predetermined angle.
Dependencies are inferred from the claim text.