Claims:We claim:

1. A method of joining components (3) made of ultra-high strength steel by a plasma arc welding process, the method comprising:
positioning one or more components (3) to be welded adjacent to each other on a welding table (5), wherein adjacent edges of the one or more components (3) to be welded define a weld zone;
orienting, a welding head (4) at a pre-defined angle ranging from 15° to 25° with respect the weld zone, wherein the welding head (4) comprises an electrode and one or more nozzles surrounding the electrode;
generating, a plasma arc in the welding head (4) by supplying plasma forming gas at a pre-determined flow rate around an electrical arc created by the electrode; and
moving, the welding head (4) along the weld zone at a pre-determined speed to direct the plasma arc along the weld zone,
wherein, plasma arc melts a portion of material along the weld zone in at least one of the one or more components to join the one or more components together.

2. The method as claimed in claim 1, wherein the one or more components are temporarily joined to define the weld zone.

3. The method as claimed in claim 1, wherein the welding head (4) is positioned at a predetermined distance from the weld zone, and the predetermined distance ranges from 5 mm to 7 mm.

4. The method as claimed in claim 1, wherein the one or more nozzles (2) includes a first nozzle (F) surrounding the electrode and a second nozzle (S) surrounding the first nozzle (F), the first nozzle (F) is configured to receive plasma gas and the second nozzle (S) is configured to receive a shielding gas.

5. The method as claimed in claim 1, wherein the electrode is ceriated tungsten electrode.

6. The method as claimed in claim 1 and 5, wherein the diameter of the electrode ranges from 3mm to 5mm.

7. The method as claimed in claim 1 and 5, wherein included angle of tip the electrode ranges from 40° to 45°.

8. The method as claimed in claim 1, wherein the plasma forming gas supplied to the welding head is a mixture of argon and hydrogen.

9. The method as claimed in claim 8, wherein composition of argon and hydrogen in the plasma forming gas is 95% and 5% respectively.

10. The method as claimed in claim 1, wherein the pre-determined flow rate of plasma gas ranges from 1.5ltr/min to 1.7ltr/min.

11. The method as claimed in claim 1, wherein the electric arc is generated by supplying a pre-determined range of electrical current, wherein the pre-determined range of electrical current is between 145 A to 155 A at a voltage ranging from 29.6V to 30.4V.

12. The method as claimed in claim 1, wherein the welding head (4) is moved at a pre-determined speed ranging from 240 mm/min to 260 mm/min.

13. The method as claimed in claim 1, wherein the welding head (4) moves along the length of the weld zone in a push-mode.

14. The method as claimed in claim 1 comprises shielding the plasma arc by passing a shielding gas encircling the plasma arc, wherein the shielding gas is supplied at a pre-defined flow rate ranging from 7ltr/min to 17ltr/min.

15. The method as claimed in claim 15, wherein the shielding gas is an inert gas.

16. The method as claimed in claim 16, wherein the inert gas is at least one of argon [Ar] and helium [He].

17. The method as claimed in claim 1, wherein the one or more components (3) are arranged adjacent to each other in butt joint configuration.

18. The method as claimed in claim 1, wherein the plasma arc current ranges from 15 A to 20 A.

19. The method as claimed in claim 1, wherein the welding head (4) is moved by a gantry arm (1a) coupled to the welding head (4).

20. A plasma arc welding system for joining components (3) made of ultra-high strength steel, the system comprising:
a welding table (5) configured to accommodate one or more components to be welded;
a gantry arm (1a) operatively coupled to a gantry (1b);
a welding head (4) movably coupled to a free end of the gantry arm (1a), wherein the welding head (4) comprises:
one or more nozzles (2) of pre-determined diameter defined with a first nozzle (F) and a second nozzle (S) surrounding the first nozzle (F), the first nozzle (F) is configured to receive plasma gas and the second nozzle (S) is configured to receive a shielding gas;
an electrode disposed within the first nozzle (F) of the one or more nozzles (2), wherein the electrode is configured to generate an electrical arc created by a pre-determined electrical current,
wherein, the electrical arc in combination with a plasma forming gas of a pre-determined flow rate generates a plasma arc in the welding head (4),
wherein, plasma arc melts a portion of material along the weld zone in at least one of the one or more components to join the one or more components together.
, Description:TECHNICAL FIELD:

Present disclosure relates in general to a field of manufacturing. Particularly, but not exclusively, the present disclosure relates high energy welding operation. Further embodiments of the present disclosure disclose a plasma arc welding system and a method of performing plasma arc welding of ultra-high strength steel material.

BACKGROUND OF THE DISCLOSURE:

Generally, welding operations are used in many industrial applications, such as vehicle construction on vehicle assembly lines. To form certain welded connections, a desired amount of the welding material must be placed between the surfaces of the weldable members where the joint is to be formed and then heated. This type of joint is difficult to form when the weldable members are complex in form because it becomes difficult to directly access the surfaces to be welded. Also, conventional welding operations cannot be used to weld materials such as high strength steel and the like.

Typically, the high strength steel finds it application or use in manufacturing body panels for armor grade vehicles which are used by officials and civilians of highest order. The armor grade vehicles are used to protect officials and civilians from various threat levels and are necessitated to meet certain requirements. For meeting such strict requirements every part of the armor grade vehicle must be made with extreme care including joining of the body panels of high strength steel using welding. As even a small defect in welding can disrupt the purpose of the armor grade vehicle.

There are other known welding operations such as high energy density welding such as plasma arc welding, laser arc welding and the like. Even in the high energy density welding operations the common problem of welding high strength steel is unavailability of welding electrodes of matching strength. Commercially available welding electrodes reach up to 1000MPa strength which is only 50% of the base metal strength. Use of the said electrodes fail to provide an undesirable joint properties which leads to joint failure. The said situation can be avoided by increasing the strength of the fusion zone. However, the same can only be achieved by using welding electrodes having strength identical to base metal strength which is practically not feasible. Further, use of autogenous welding i.e., using energy source for melting the base metal without filler metal may be used. Use of such autogenous high energy density [HED] welding operations to fuse the high strength steel materials have certain drawbacks. For example, plasma arc welding leads to formation of undercut and porosity which reduces the joint strength, thickness limitation, joints become crack sensitive due to lack of molten metal supply during solidification etc.

The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the conventional arts.

The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of the conventional arts are overcome by an apparatus and a method as claimed and additional advantages are provided through the provision of apparatus and the method as claimed in the present disclosure.

Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the disclosure, a method of joining components made of ultra-high strength steel by a plasma arc welding process is disclosed. The method includes positioning one or more components to be welded adjacent to each other on a welding table, such that adjacent edges of the one or more components to be welded defines a weld zone. The method includes orienting a welding head at a pre-defined angle ranging from 15° to 25° with respect the weld zone. The weld head comprises an electrode and one or more nozzles surrounding the electrode. Further, in the method plasma arc is generated in the welding head by supplying plasma forming gas at a pre-determined flow rate around an electrical arc created by the electrode. The welding head is then moved along the weld zone at a pre-determined speed to direct the plasma arc along the weld zone. Plasma arc melts a portion of material along the weld zone in at least one of the one or more components to join the one or more components together.

In an embodiment of the disclosure, the one or more components are temporarily joined to define the weld zone.

In an embodiment of the disclosure, the welding head is positioned at a predetermined distance from the weld zone. The predetermined distance ranges from 5mm to 7mm.

In an embodiment of the disclosure, the one or more nozzles includes a first nozzle surrounding the electrode and a second nozzle surrounding the first nozzle. The first nozzle is configured to receive plasma gas and the second nozzle is configured to receive a shielding gas.

In an embodiment of the disclosure, the electrode is ceriated tungsten electrode. The diameter of the electrode ranges from 3mm to 5mm. The included angle of tip of the electrode ranges from 40° to 45°.

In an embodiment of the disclosure, the plasma forming gas supplied to the welding head is a mixture of argon and hydrogen. Composition of argon and hydrogen in plasma forming gas is 95% and 5% respectively. Further, the predetermined flow rate of plasma gas ranges from 1.5ltr/min to 1.7ltr/min.

In an embodiment of the disclosure, the electric arc is generated by supplying a pre-determined range of electrical current. The pre-determined range of electrical current is between 145A to 155A at a voltage ranging from 29.6V to 30.4V.

In an embodiment of the disclosure, the welding head is moved at a predetermined speed ranging from 240mm/min to 260mm/min. The welding head is moved along the length of the weld zone in a push mode.

In an embodiment of the present disclosure, the method includes shielding the plasma arc by passing a shielding gas encircling the plasma arc. The shielding gas is supplied at a pre-defined flow rate ranging from 7ltr/min to 17ltr/min. the shielding gas is an inert gas. The inert gas is at least one of argon and helium.

In an embodiment of the present disclosure, the one or more components are arranged adjacent to each other in butt joint configuration.

In an embodiment of the present disclosure, the plasma arc current ranges from 15A to 20A.

In an embodiment of the present disclosure, the welding head is moved by a gantry arm coupled to the welding head.

In another non-limiting embodiment of the disclosure, a plasma arc welding system for joining components made of ultra-high strength steel is disclosed. The system includes a welding table configured to accommodate one or more components to be welded, and a gantry arm which is operatively coupled to a gantry. The system also includes a welding head movably coupled to a free end of the gantry arm. The welding head includes one or more nozzles of pre-determined diameter defined with a first nozzle and a second nozzle surrounding the first nozzle. The first nozzle is configured to receive plasma gas and the second nozzle is configured to receive a shielding gas. An electrode is disposed within the first nozzle of the one or more nozzles. The electrode is configured to generate an electrical arc created by a predetermined electrical current. The electrical current in combination with a plasma forming gas of pre-determined flow rate generates a plasma arc in the welding head. Plasma arc melts a portion of material along the weld zone in at least one of the one or more components to join the one or more components together.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

FIG.1 illustrates schematic view of a plasma arc welding system for joining components made of ultra-high strength steel, in accordance with an embodiment of the present disclosure.

FIG.2 illustrates enlarged sectional view of a nozzle for plasma arc welding system of FIG.1, in accordance with an embodiment of the present disclosure.

FIG.3 is a flow diagram of a method of joining components made of ultra-high strength steel, in accordance with an embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent processes do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

Embodiments of the present disclosure discloses a method of joining components made of ultra-high strength steel by a plasma arc welding process. The method of according to the present disclosure ensure a defect free weld in autogenous route (i.e., without using welding electrodes/filler metal) without compromising on mechanical joint efficiency. The method of the present disclosure eliminates costly and time-consuming post-weld heat treatments for improving mechanical properties of the joint. Also, the method of joining components according to the present disclosure eliminates problems such as lack of fusion, under cut, entrapped porosity, and surface cracks.

According to embodiments of the disclosure, the method of joining components made of ultra-high strength steel [hereinafter referred to as UHSS] may include positioning one or more components to be welded adjacent to each other on a welding table of a plasma arc welding system [hereinafter referred to as system]. The one or more components are arranged adjacent to each other in a butt joint configuration. In an embodiment, the adjacent edges of the one or more components to be welded may define a weld zone. The method further includes positioning a welding head at a pre-determined angle with respect to the weld zone. The pre-determined angle of orientation of the welding head ranges from 15° to 25°. The welding head may be positioned at a pre-determined distance from the weld zone. The pre-determined distance may range from 5mm to 7mm.

A plasma arc may be generated in the welding head by supplying plasma forming gas around an electrical arc created by an electrode in the welding head. The plasma forming gas may be supplied around the electrical arc at a predetermined flow rate ranging from 1.5ltr/min to 1.7ltr/min. The plasma forming gas may be a mixture of argon and hydrogen of composition 95% and 5% respectively. The plasma arc generated is directed on to the weld zone of the one or more components to melt a portion of material along the weld zone to join the one or more components together. The weld head may be moved along the weld zone at a predetermined speed to direct the plasma arc along the weld zone. The predetermined speed of the weld head may range from 240mm/min to 260mm/min. The method of the present disclosure use the part of UHSS material to form a joint at a controller rate, and thereby eliminate the problems associated with conventional joining method of the UHSS.

The terms “comprises…. a”, “comprising”, or any other variations thereof used in the specification, are intended to cover a non-exclusive inclusion, such that an assembly that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or method. In other words, one or more elements in an assembly proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the assembly.

Henceforth, the present disclosure is explained with the help of one or more figures of exemplary embodiments. However, such exemplary embodiments should not be construed as limitation of the present disclosure.

The following paragraphs describe the present disclosure with reference to FIG(s) 1 to 3. In the figures, the same element or elements which have similar functions are indicated by the same reference signs. For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to specific embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated methods, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention pertains.

The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description. It is to be understood that the disclosure may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices or components illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions or other physical characteristics relating to the embodiments that may be disclosed are not to be considered as limiting, unless the claims expressly state otherwise. Hereinafter, preferred embodiments of the present disclosure will be described referring to the accompanying drawings. While some specific terms of “upper,” “lower,” “below”, “above”, “right,” “along”, or “left” and other terms containing these specific terms and directed to a specific direction will be used, the purpose of usage of these terms or words is merely to facilitate understanding of the present invention referring to the drawings. Accordingly, it should be noted that the meanings of these terms or words should not improperly limit the technical scope of the present invention.

As an initial matter it should be noted that the term “gun” may be used in the welding and cutting industry to describe an elongated, flexible harness called the “cable” comprising an isolation tube with a rear end connectable to a power supply system of the type including a power source with a controller and a wire feeder (in welding systems). The front end of the “gun” has a torch to perform the desired operation. The terms “torch” and “gun” are often used interchangeably to mean either the welding/cutting head or the whole unit. Generally, in the following description, the “torch” may be called a welding head (4) However, in some instances the term “gun” may be used herein to describe the welding head (4). In any event, the context of which the terms are used herein will sufficiently explain how the terms are used.

Referring to drawings, a plasma arc welding system (10) incorporating the principles of the present disclosure is illustrated in FIG.1. The plasma arc welding system (10) may hereinafter be referred to as system (10) and may be used alternatively in the present disclosure. The system (10) of the present disclosure may include a welding table (5). The welding table (5) may be configured to accommodate one or more components to be welded. The welding table (5) is configured to act as a base and may support the one or more components. In an embodiment, the welding table (5) may be an electromagnetic base that may be selectively activated and deactivated to securely hold the one or more components to be welded. In some other embodiments, the welding table (5) may be defined with various fixture elements such as but not limiting to clamps and the like.

The system (10) further includes a welding head (4). The welding head (4) may be movably coupled to a free end of a gantry arm (1a). The gantry arm (1a) of the present disclosure may be operatively coupled to a gantry (1b). The gantry (1b) may be supported at either ends by a plurality of support structures. Configuration of the welding head (4) described hereinafter may be used for manual, mechanized, and automated applications and are intended to be included with in the scope of the present disclosure. The welding head (4) includes an electrode (E) [as shown in FIG.2], such as but not limiting to ceriated tungsten electrode (E), secured within the welding head (4). The electrode (E) may be insulated from the welding head (4) by means of an insulated material so that the electrode (E) is isolated from the welding head (4). Electrical power, either alternating current or direct current, may be supplied from a source through electrical leads between the one or more components and the electrode (E). In an embodiment, diameter of the electrode (E) may range from 3mm to 5mm and the included angle of tip of the electrode (E) ranges from 40° to 45°. Further, the welding head (4) includes one or more nozzles (2). The one or more nozzles (2) may be of predetermined diameter. In an embodiment, the one or more nozzles (2) includes a first nozzle (F) and a second nozzle (S) [as shown in FIG2].

The first nozzle (F) may encompass/encircle the electrode (E). In an embodiment, a first plenum chamber (FC) may be defined within the first nozzle (F) and the electrode (E). The first plenum chamber (FC) [as shown in FIG.2] within the first nozzle (F) may be configured to receive a plasma forming gas from a plasma forming gas source. In an embodiment, the plasma forming gas that may be used in the present disclosure may be mixture of argon and hydrogen but not limiting to the same. Concentration of argon and hydrogen in the mixture of plasma forming gas may be 95% and 5% respectively. The said concentration should not be construed as a limitation of the present disclosure. Further, the first nozzle (F) may be encompassed by a second nozzle (S). The second nozzle (S) surrounds the first nozzle (F) defining a second plenum chamber (SC). The second plenum chamber (SC) [as depicted in FIG.2] may be configured to receive a shielding gas. The shielding gas may be an inert gas such as but not limiting to at least one of argon [Ar] and helium [He]. In an embodiment, the first nozzle (F) and the second nozzle (S) may be made of materials such as but not limiting to copper alloy. The welding head (4) of the said configuration may be configured to act as a torch/gun. The welding head (4) may be connected to a flexible harness cable which may be configured to receive electrical current from the source. In some instances, the flexible harness may be configured to communicate the gases from source to the welding head (4). Hereinafter, the method of welding an ultra-high strength steel using the said configuration may be elucidated.

Referring to FIG.3 in conjunction with FIG(s).1 and 2, the method of fusing or joining the one or more components made of ultra-high strength steel by the said plasma arc welding process includes positioning of the one or more components to be welded on the welding table (5). The method of the present disclosure may be performed in an autogenous route. The autogenous weld is a form of welding, where the filler material is either supplied by melting the base material or is of identical composition. In an embodiment, the one or more components to be welded may be arranged adjacent to each other in butt joint configuration. Initially adjacent edges of the one or more components may be joined temporarily using know welding process such as but not limiting to TIG welding. The adjacent edges of the one or more components to be welded may define a weld zone. The welding head (4) may be moved proximal to one or more components to be welded i.e., the welding head (4) may be positioned substantially above the one or more components. The welding head (4) may be aligned with respect to the weld zone. The welding head (4) may be positioned at a pre-determined distance from the weld zone defined by the one or more components. The pre-determined distance may range from 5mm to 7mm i.e., the welding head (4) may be positioned above the weld zone at a distance ranging from 5mm to 7mm.

Once, the welding head (4) is aligned with the weld zone of the one or more components, the welding head (4) may be oriented at a pre-defined angle with respect to the weld zone. The said pre-determined angle may range from 15° to 25° with respect to the weld zone.

Further, a plasma arc may be generated by supplying the plasma forming gas through the first plenum chamber (FC) at a pre-determined flow rate. The pre-determined flowrate of the plasma forming gas ranges from 1.5ltr/min to 1.7ltr/min. The plasma forming gas may supplied through the first plenum chamber (FC) around the electrode (E). Further, the plasma forming gas may be heated by an arc generated between the electrode (E) and the one or more components by supplying a pre-determined range of electrical current through the electrode (E). The pre-determined range of electrical current may range between 145 A to 155 A with a voltage ranging from 29.6V to 30.4V. As iterated earlier the plasma forming gas may be heated by the by the arc which expands and exits through an orifice of the nozzle (2) at an accelerated rate. In an embodiment, the orifice diameter of the nozzle (2) may range from 1mm to 4mm.

The arc is columnated into a dense energy source and focused on to the welding zone by the nozzle (2) [due to the constricting nature]. The plasma forming gas may supply the necessary atmosphere for allowing electrical transfer of the arc across the gap between the electrode (E) and the one or more components and may be ionized in the arc to form the plasma which issues from the orifice as the plasma arc [also called as plasma jet]. In an embodiment, the plasma arc current may be controlled and may range from 15A to 20 A. Further, the plasma arc/ plasma jet may be directed from the nozzle (2) to the weld zone defined by the one or more components to be welded. The plasma arc melts a portion of material along the weld zone in at least one of the one or more components, thereby fusing the components together. In an embodiment, the welding head (4) may be moved along the weld zone at a pre-determined speed to direct the plasma arc along the weld zone to join the one or more components. The welding head (4) may be moved along the weld zone in a push mode i.e., the welding head (4) may be pushed from one end of the weld zone to another end of the weld zone at the predetermined speed. The pre-determined speed of welding head (4) may range from 240mm/min to 260mm/min.

Further, the second plenum chamber (SC) communicates the shielding gas for the welding process. The second plenum chamber (SC) defined between the first and the second nozzle (F and S) may be supplied with a shielding gas which as described above may be an inert gas, such as argon. The shielding gas may be configured to blanket the area of plasma arc impingement upon the weld zone [i.e., to encircle the plasma arc] of the one or more components to provide a total inert atmosphere at the weld zone to prevent contamination. The shielding gas is supplied through the second plenum chamber (SC) at a pre-determined flow rate ranging from 7ltr/min to 17ltr/min. In some embodiments, a coolant may be circulated through the troch [i.e., the welding head] to cool and dissipate the heat generated in the first nozzle (F) or second nozzle (S).

In an embodiment, the method according to the present disclosure ensures a defect free weld in the autogenous route (i.e., without using welding electrodes/filler metal) without compromising on mechanical joint efficiency. The method of the present disclosure may be employed in welding materials made of ultra-high strength steel as described of thickness ranging from 1mm to 6mm. The method of the present disclosure eliminates costly and time-consuming post-weld heat treatments for improving mechanical properties of the joint. Also, the method of joining the one or more components according to the present disclosure eliminates problems such as lack of fusion, under cut, entrapped porosity, and surface cracks.

It is to be understood that a person of ordinary skill in the art may develop a system of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.

Equivalents

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding the description may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated in the description.

Referral Numerals:
Description Reference number
Plasma arc welding system 10
Gantry arm 1a
Gantry 1b
Nozzle 2
Component to be welded 3
Welding head 4
Welding table 5
Electrode E
First nozzle F
Second nozzle S
First plenum chamber FC
Second plenum chamber SC