Patent Application
20110095000
The present disclosure generally relates to weldable workpieces and welding processes. In particular, the present disclosure relates to workpieces and welding processes that prevent the formation of pores in welds.
Structures and articles are continuously being designed and produced to be larger, to be more complex, and to have increased strength. Often, weld points are one of the weaker parts of such structures and articles.
Generally, welds secure two workpieces together. For example, a first workpiece may be secured to a second workpiece thereby forming a desired structure, article, or part of a structure or article. The welded workpieces may be subjected to numerous physical forces. For example, welded workpieces may experience compressive and tensile forces as a structure sways. In addition, physical forces may result from other factors, including but not limited to, environmental effects, operational effects, and/or exposure to changing conditions. If a weld is unsuccessful, the parts may be more susceptible to failure. For example, physical forces can produce fatigue loading on structures having welded parts. This fatigue can result in failure of the weld and failure of the structure.
Generally, welds can be formed by partially melting workpieces and optionally adding a filler material that cools to become a joint. The partial melting of the workpieces and/or the filler material requires energy. The energy can be provided by a gas flame, an electric arc, a laser, an electron beam, friction, ultrasound, or other suitable sources of energy.
Electron beam welding and laser beam welding can have a smaller heat-affected zone than other welding methods permitting focused energy, reduced distortion, and rapid cooling. However, electron beam welding and laser beam welding can emit gases. To reduce or eliminate the gases, deoxidizers (which reduce or remove oxygen content in metal) can be used. The deoxidizer can reduce or eliminate weld porosity, which may reduce the strength of the weld. Exclusively using deoxidizer for reducing or eliminating weld porosity can provide compositional limitations on workpieces.
In an exemplary embodiment, an article for a welding process includes a workpiece, the workpiece including a first weld surface, the first weld surface including at least one porosity reducing channel, the at least one porosity reducing channel being configured to prevent the formation of pores in a formed weld.
In another exemplary embodiment, an article for welding includes a workpiece, the workpiece includes a first weld surface, the first weld surface including at least one porosity reducing channel, the at least one porosity reducing channel being configured to direct gas from the weld surface when a weld is being formed.
In another exemplary embodiment, a welding process includes positioning a first workpiece, the first workpiece including a first weld surface, the first weld surface including at least one porosity reducing channel, positioning a second workpiece, the second workpiece including a second weld surface, the second weld surface being positioned to be welded to the first weld surface, and applying energy to the first weld surface and the second weld surface thereby forming a weld, the application of energy generating gas, the gas being directed by the at least one porosity reducing channel. In the embodiment, the welding process includes at least one of an electron beam welding process or a laser welding process.
Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.
Provided is an exemplary embodiment of a weldable workpiece and a method for welding workpieces that prevents the formation of pores in welds. The prevention of the formation of pores in welds is additional or alternative to prevention achieved by including deoxidizer in the composition of the workpiece. Embodiments may improve weld quality, may prevent porosity in welds, may direct gases emitted from laser welding and/or electron beam welding, and/or may be an alternative to including deoxidizer in workpiece composition.
As shown in
Referring to
In one exemplary embodiment, workpieces 102, 104 may include deoxidizers or other suitable additives. Deoxidizers may be fluxes or active shield gases, or other suitable additives.
Referring to
Porosity reducing channels 116 in first workpiece 102, second workpiece 104, and/or combinations thereof can depend upon the material from which the workpiece is made, the thickness of the workpiece, a predetermined vacuum level, properties of a predetermined filler material (for example, melt temperature, viscosity when melted, amount of gas emitted during weld, etc.), an amount of air in the material, a predetermined energy level, and/or a predetermined welding travel speed. Workpieces 102, 104 made of a material that generates a larger amount of gas when being laser welded or electron beam welded may include more and/or larger porosity reducing channels 116. In contrast, workpieces 102, 104 made from a material that generates a smaller amount of gas when being laser welded or electron beam welded may include fewer and/or smaller porosity reducing channels 116. Workpieces 102, 104 having a larger thickness may include more and/or larger porosity reducing channels 116. In contrast, workpieces 102, 104 having a smaller thickness may include fewer and/or smaller porosity reducing channels 116. Workpieces 102, 104 to be welded in a higher vacuum may include fewer and/or smaller porosity reducing channels 116. In contrast, workpieces 102, 104 to be welded in a lower vacuum (or in no vacuum) may include greater and/or larger porosity reducing channels 116. Workpieces 102, 104 to be welded with a higher viscosity and/or higher gas generating filler material may include more and/or larger porosity reducing channels 116. In contrast, workpieces 102, 104 to be welded with a lower viscosity and/or lower gas generating filler may include fewer and/or smaller porosity reducing channels 116. Workpieces 102, 104 having a higher concentration of air in the metal may include fewer and/or smaller porosity reducing channels 116. In contrast, workpieces 102, 104 having a lower concentration of air in the metal may include more and/or larger porosity reducing channels 116. Workpieces 102, 104 to be welded at a higher amount of energy may include fewer and/or smaller porosity reducing channels 116. In contrast, workpieces 102, 104 to be welded at a lower amount of energy may include more and/or larger porosity reducing channels 116. Workpieces 102, 104 to be welded at a slower weld travel speed may include fewer and/or smaller porosity reducing channels 116. In contrast, workpieces 102, 104 to be welded at a higher weld travel speed may include more and/or larger porosity reducing channels 116. However, depending upon the specific workpieces 102, 104, the amount, size, and/or orientation of porosity reducing channels 116, porosity reducing channels 116 can be affected by the above properties to varying degrees or even in the reverse.
Referring to
Knurled surface 120 in first workpiece 102, second workpiece 104, and/or combinations thereof can depend upon the material from which the workpiece is made, the thickness of the workpiece, a predetermined vacuum level, properties of a predetermined filler material, an amount of air in the material, a predetermined energy level, and/or a predetermined welding travel speed. Workpieces 102, 104 made of a material that generates a larger amount of gas when being laser welded or electron beam welded may include larger, more, and/or deeper knurled surfaces 120. In contrast, workpieces 102, 104 made of a material that generates a smaller amount of gas when being laser welded or electron beam welded may include fewer, smaller, and/or shallower knurled surfaces 120. Workpieces 102, 104 having a larger thickness may include larger, more, and/or deeper knurled surfaces 120. In contrast, workpieces 102, 104 having a smaller thickness may include smaller, fewer and/or shallower knurled surfaces 120. Workpieces 102, 104 to be welded in a higher vacuum may include smaller, fewer and/or shallower knurled surfaces 120. In contrast, workpieces 102, 104 to be welded in a lower vacuum (or in no vacuum) may include larger, more, and/or deeper knurled surfaces 120. Workpieces 102, 104 to be welded with a higher viscosity and/or higher gas generating filler material may include larger, more, and/or deeper knurled surfaces 120. In contrast, workpieces 102, 104 to be welded with a lower viscosity and/or lower gas generating filler may include smaller, fewer, and/or shallower knurled surfaces 120. Workpieces 102, 104 having a higher concentration of air in the metal may include smaller, fewer, and/or shallower knurled surfaces 120. In contrast, workpieces 102, 104 having a lower concentration of air in the metal may include smaller, fewer, and/or shallower knurled surfaces 120. Workpieces 102, 104 to be welded at a higher amount of energy may include smaller, fewer, and/or shallower knurled surfaces 120. In contrast, workpieces 102, 104 to be welded at a lower amount of energy may include larger, more, and/or deeper knurled surfaces 120. Workpieces 102, 104 to be welded at a slower weld travel speed may include smaller, fewer, and/or shallower knurled surfaces 120. In contrast, workpieces 102, 104 to be welded at a higher weld travel speed may include larger, more, and/or deeper knurled surfaces 120. However, depending upon the specific workpieces 102, 104, the amount, size, depth, and/or orientation of knurled surface(s) 120 can be affected by the above properties to varying degrees or even in the reverse.
Referring to
Vent path 118 in first workpiece 102, second workpiece 104, and/or combinations thereof can depend upon the material from the workpiece is made, the thickness of the workpiece, a predetermined vacuum level, properties of a predetermined filler material, an amount of air in the material, a predetermined energy level, and/or a predetermined welding travel speed. Workpieces 102, 104 made from a material that generates a larger amount of gas when being laser welded or electron beam welded may include a vent path 118 having a smaller angle 119, shorter length, and lower degree of tortuousness. In contrast, workpieces 102, 104 made from a material that generates a smaller amount of gas when being laser welded or electron beam welded may include a vent path 118 having a greater angle 119, longer length, and higher degree of tortuousness. Workpieces 102, 104 having a larger thickness may include a vent path 118 having a smaller angle 119, shorter length, and lower degree of tortuousness. In contrast, workpieces 102, 104 having a smaller thickness may include a vent path 118 having a greater angle 119, longer length, and higher degree of tortuousness. Workpieces 102, 104 to be welded in a higher vacuum may include a vent path 118 having a greater angle 119, longer length, and higher degree of tortuousness. In contrast, workpieces 102, 104 to be welded in a lower vacuum (or in no vacuum) may include a vent path 118 having a smaller angle 119, shorter length, and lower degree of tortuousness. Workpieces 102, 104 to be welded with a higher viscosity and/or higher gas generating filler material may include a vent path 118 having a smaller angle 119, shorter length, and lower degree of tortuousness. In contrast, workpieces 102, 104 to be welded with a lower viscosity and/or lower gas generating filler may include a vent path 118 having a greater angle 119, longer length, and higher degree of tortuousness. Workpieces 102, 104 having a higher concentration of air in the metal may include a vent path 118 having a greater angle 119, longer length, and higher degree of tortuousness. In contrast, workpieces 102, 104 having a lower concentration of air in the metal may include a vent path 118 having a smaller angle 119, shorter length, and lower degree of tortuousness. Workpieces 102, 104 to be welded at a higher amount of energy may include a vent path 118 having a greater angle 119, longer length, and higher degree of tortuousness. In contrast, workpieces 102, 104 to be welded at a lower amount of energy may include a vent path 118 having a smaller angle 119, shorter length, and lower degree of tortuousness. Workpieces 102, 104 to be welded at a slower weld travel speed may include a vent path 118 having a greater angle 119, longer length, and higher degree of tortuousness. In contrast, workpieces 102, 104 to be welded at a higher weld travel speed may include a vent path 118 having a smaller angle 119, shorter length, and lower degree of tortuousness. However, depending upon the specific workpieces 102, 104, the angle 119, length, and/or degree of tortuousness can be affected by the above properties to varying degrees or even in the reverse.
Referring to
Referring to
According to an exemplary embodiment, welding may be performed by positioning first workpiece 102 and second workpiece 104 or a workpiece 106 devoid of porosity reducing channels 116 or knurled surfaces 120, applying energy to first weld surface 116 of first workpiece 102 and a second weld surface of second workpiece 104 or prior art workpiece 106 can form a weld with reduced porosity by directing gases with porosity reducing channel and/or knurled surface 120 away from weld 112.
While the disclosure has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.
