FR3054150A1 - METHOD AND DEVICE FOR WELDING WORKPIECES HAVING HEAT-SENSITIVE MATERIAL - Google Patents

Abstract

Method and apparatus for welding workpieces having a heat-sensitive material are provided. The heat sensitive material comprises austenitic manganese steel, also called Hadfield manganese steel. The process gives a filler metal a back and forth motion in and out of the weld pool. The displacement of the filler metal may be synchronized with the waveform of the energy source (111). Welding parameters are adjusted so that the weld can be performed on the work piece (150) without cracking the heat-sensitive material. The method allows Hadfield manganese steel to be welded to generator components in power generation applications. The process provides a reliable and repeatable quality weld.

Description

Holder (s): SIEMENS ENERGY, INC ..

Extension request (s)

Agent (s): CABINET FLECHNER.

METHOD AND DEVICE FOR WELDING WORKPIECES HAVING HEAT SENSITIVE MATERIAL.

FR 3 054 150 - A1 (5g) Method and device for welding work pieces having a material sensitive to heat are proposed. The heat sensitive material includes austenitic manganese steel, also called Hadfield manganese steel. The process gives a filler metal back and forth in and out of the weld pool. The displacement of the filler metal can be synchronized with the waveform of the energy source (111). Welding parameters are adjusted so that welding can be performed on the work piece (150) without cracking the heat sensitive material. The method allows Hadfield manganese steel to be welded to generator components in power generation applications. The process provides a reliable and repeatable quality weld.

METHOD AND DEVICE FOR WELDING WORKPIECES HAVING HEAT SENSITIVE MATERIAL

TECHNICAL FIELD This invention relates generally to a method and to a device for welding a workpiece having a heat-sensitive material, in particular austenitic manganese steel.

DESCRIPTION OF THE PRIOR ART Fusion welding is a process which uses thermal energy to melt materials to be joined and create a solid joint when it has solidified. Arc welding is one of the most classic fusion welding techniques, in which coalescence of metals takes place using heat from an arc between a continuously supplied filler metal and a weld surface of a base metal. The fusion welding process is a widely used welding technique. However, this method can heat the weld surface to a temperature which creates undesirable changes in the material, such as hardening and warping, and under extreme conditions leads to cracking of the materials.

A widely used subset of austenitic manganese steel is Hadfield manganese steel, which is a non-magnetic alloy with high strength and extremely dense. It is of great interest for generator components in power / current generation applications. However, Hadfield manganese steel is sensitive to heat. It can crack if overheated. Fusion welding of Hadfield manganese steel is extremely difficult, as the material is likely to crack if overheated during welding.

SUMMARY OF THE INVENTION Briefly described, aspects of the present invention relate to a method and a device for welding a workpiece having heat sensitive material, in particular austenitic manganese steel.

In one aspect, a welding method for welding a workpiece is presented. The method includes the step of providing electrical energy from an energy or current source to a contact tip of a welding torch. The method includes providing a filler metal from a filler metal feeder and causing the filler metal to extend through the contact tip toward the workpiece. The workpiece includes a heat sensitive material. The method includes melting a portion of the work piece to create a weld pool on the weld piece by an arc produced between a tip of the filler metal and a surface of the work piece. The method includes giving the filler metal back and forth to enter and exit the weld pool. The method includes synchronizing a displacement of the filler metal with an electrical power waveform. The method includes adjusting a weld setting, so that a weld can be made to the workpiece without cracking the heat sensitive material.

Preferably, the filler metal has a solid wire shape.

In one aspect, a welding device for welding a workpiece is presented. The welding device comprises a welding torch having a contact tip. The welding device includes an energy source configured to supply electrical energy to the contact tip of the welding torch. The welding device includes a filler metal feeder configured to provide a filler metal extending through the contact tip to the workpiece. The workpiece includes a heat sensitive material. An arc is produced between a tip of the filler metal and a surface of the work piece to create a weld pool on the work piece. The welding device comprises a driving device configured to give the filling metal a reciprocating movement to enter and leave the welding bath. The power source includes a digital signal processor. The digital signal processor is configured to send a signal to the driver, so that movement of the filler metal is synchronized with a waveform of electrical energy. A weld setting is set so that a weld can be made to the work piece without cracking the heat sensitive material.

Various aspects and embodiments of the application as described above and below can not only be used in combinations explicitly described, but also in other combinations. Modifications will appear to those skilled in the art on reading and understanding the description.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments as examples of the application are described in more detail with reference to the accompanying drawings. At drawings :

FIG. 1 illustrates a diagram in the form of a diagram of a welding device for welding a work piece having heat-sensitive material using a gaseous metal arc weld supplied by a wire back and forth according to one embodiment;

Figure 2 illustrates a diagram in the form of a diagram of an arc welding process with gaseous metal;

FIG. 3 illustrates a diagram in the form of a diagram of voltage and current waveforms of an electric power device in a mode of transfer of metal in short circuit from solder to 'gas metal arc;

FIG. 4 illustrates a diagram in the form of a diagram of a control system for an arc welding process with gaseous metal fed by a wire back and forth;

F igure 5 illustrates steps of moving a filler metal in an arc welding process with gaseous metal supplied by a wire back and forth;

Figure 6 illustrates a cross-sectional view in the form of a diagram of a joint geometry of a workpiece having a heat-sensitive material according to one embodiment;

FIG. 7 illustrates a diagram in the form of a diagram of an orientation or working angle of a work piece having a material sensitive to heat according to one embodiment;

FIG. 8 illustrates a diagram in the form of a diagram of an orientation or angle of displacement of a work piece having a material sensitive to heat according to one embodiment;

FIG. 9 illustrates a perspective view of a pattern of cord in the form of a wire of a work piece having a material sensitive to heat according to one embodiment; and FIG. 10 illustrates a perspective view of a bead-like pattern of a work piece having a heat-sensitive material according to one embodiment.

To facilitate understanding, identical reference numbers have been used, as much as possible, to designate identical elements which are common to the figures.

DETAILED DESCRIPTION OF THE INVENTION A detailed description relating to aspects of the present invention is given below with reference to the accompanying figures.

Figure 1 illustrates a diagram in the form of a diagram of a welding device 100 according to one embodiment. The welding device 100 may include a supply unit 110. The supply unit 110 may include a source 111 of energy, a device 116 for supplying filler metal, and a device 117 for supplying shielding gas. The energy source 111 can be electrically connected to the device 116 for supplying filler metal. The energy source 111 can be electrically connected to the device 117 for supplying shielding gas. The welding device 100 can comprise a welding torch or torch 130. The torch 130 can be functionally connected to the supply unit 110 via an insulating conduit 131. The torch 130 can perform a welding process on a work piece 150. The welding device 100 may include a control unit 120. The control unit 120 can be operatively connected to the power supply box 110.

The fusion welding process is widely used in industrial applications. A gas metal arc welding (GMAW) process is one of the most conventional fusion welding processes. FIG. 2 illustrates a diagram in the form of a diagram of a GMAW process. A torch 130 may include an insulating conduit 131. The insulating conduit 131 can enclose a power cable 132. The power cable 132 can be connected to a source 111 of energy. The torch 130 may include a contact tip 136. The power cable 132 can supply electrical energy to the contact tip 136 from the energy source 111. The distance from the work piece to the contact tip (CTWD) 137 may refer to a distance from the contact tip 136 to a surface of the work piece 150. The insulated conduit 131 can enclose a metal 138 for filling. The filler metal 138 can be supplied from the filler metal supply device 116. The filling metal 138 can extend through the contact tip 136 in the direction of a work piece 150. The electrical energy from the contact tip 136 can be transmitted to the filler metal 138 at the contact tip 136. The extension of the filling metal 138 by the contact tip 136 can become an electrode. The insulating conduit 131 can enclose a pipe 133 of shielding gas. The shielding gas hose 133 can be connected to the shielding gas supply device 117. Shielding gas 118 can be sent to the torch 130 through the shielding gas pipe 133. The torch 130 may include a gas nozzle 134. The shielding gas 118 can create a gaseous shield 135 when it passes through the gas nozzle 134.

During a welding process, an arc 139 can be produced when the metal 138 filler is in contact with a surface of the work piece 150. Arc 139 can produce heat. The heat supplied from the arc 139 can melt part of the work piece 150 to create a weld pool 140. The heat from the arc 139 can melt a tip of the filler metal 138. The molten tip of the filler metal 138 can be transferred to the weld pool 140. Welding metal 141 can be formed on the work piece 150 after solidification. The gas protection 135 can prevent atmospheric contamination of the filler metal 138, the arc 139 and the weld pool 140 during welding.

In a GMAW process, a metal transfer by short circuit can produce a relatively low amount of heat compared to other metal transfer mechanisms, such as globular metal transfers, metal transfers by sputtering, metal transfers by pulsed spraying. Figure 3 illustrates a diagram in the form of a voltage and current waveform diagram of electrical power in a short-circuit metal transfer. A short circuit can be created at an instant A when the molten tip of the filler metal 138 touches the weld pool 140. Arc 139 can go out at time A. The voltage of electric power can decrease at time A. The current of electric power can increase at time A. The increasing current can produce a force of magnetic pinch. The magnetic pinching force can cause the molten tip of the filler metal 138 to be transferred to the weld pool 140 at instant B. The arc 139 can reactivate when contact between the tip of the filler metal 138 and the Solder bath 140 breaks at time C. The metal transfer cycle can be repeated with a duration D of arc formation and a short circuit at time E. The filler metal 138 can be fed continuously from the device 116 for supplying the filling metal in the direction of the work piece 150 in the weld bath 140 during the cycle.

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The problems of a GMAW transfer of metal by shortlieu to classic short-circuits are associated with random circuits which can have erratic time intervals of variable intensities. The resulting agitation of a solder bath results in solder spatter, side wall gels, cold spins and lack of fusion. A high level of splashing may be produced. The heat produced in a conventional GMAW metal transfer by short circuit can be relatively too high and crack a work piece 150 having a heat sensitive material.

Feeding processes (RWF) -GMAW with feed by wires performing a back-and-forth movement have been developed by several manufacturers of welding equipment to respond to the problems which arise in the short-term transfer of metal. classic GMAW circuit. In the RWF-GMAW processes, a filler metal 138, such as a wire, can go back and forth to get in and out of a weld pool 140, rather than moving continuously toward the before in a classic GMAW process. The movement of the filling metal 138 can be controlled by electronic regulation inside a source 111 of energy. The movement of the filler metal 138 can be synchronized with a waveform of the energy source 111. Examples of RWF-GMAW processes can include Fronius Cold Metal Transfer, Jetline Controlled Short Circuit, SKS MicroMig Welding System, Panasonic Active Wire Process, etc.

FIG. 4 illustrates a diagram in the form of a diagram of a control system for an RWFGMAW process. The system may include a source 111 of energy. The energy source 111 may include an analog / digital (A / D) current converter 112. The 112 A / D converter can convert a power signal from analog to digital. The digitized power signal can be processed by a Digital Signal Processor (DSP) 113. When the DSP 113 detects a short circuit, it can send a signal to a drive device 115 to remove a metal 138 filler from outside. 140 a solder bath. The molten tip of the filler metal 138 can be transferred to the weld pool 140 by a combination of mechanical retraction force of the drive device 115 and a nip force of an increased short-circuit current. The DSP 113 can send a signal to the drive device 115 to feed the filling metal 138 forward towards the weld pool 140 when an arc 139 is reactivated. The cycle can be repeated when a short circuit occurs again. The energy source 111 can include an inverter 114. The inverter 114 can provide a fast digitized closed feedback control of the current and voltage of the energy source 111. The DSP 113 can be connected to a control unit 120, to a device 116 for supplying filling metal and to a device 117 for supplying shielding gas via an interface, such as a bus. 119 of data. Welding parameters can be stored in the DSP 113 for a combination of different working parts 150, filling metal 138 and protective gas 118. The control unit 120 can monitor, display or document the welding parameters to guarantee an optimum welding process.

Figure 5 illustrates steps of moving a filling metal 138 in an RWF-GMAW process. During an arc formation period in step 210, an arc 139 may be established between a tip of the filler metal 138 and a surface of the work piece 150. Heat from the arc 139 can create a weld pool 140 on the surface of the work piece 150. The filler metal 138 can be moved forward toward the weld pool 140 during the arcing period in step 210. A short circuit can be created when the tip of the filler metal 138 touches the bath 140 of soldering in step 220. The arc 139 can be extinguished for the duration of the short circuit. The filler metal 138 can be removed mechanically from the weld pool 140 to support the transfer of metal during the short-circuit period in step 230. The arc 139 can reactivate again when contact between the tip of the filling metal 138 and the weld pool 140 is broken in step 210. The displacement of the metal

138 filling can be reversed again towards the weld pool 140 during the arc formation time as illustrated in step 210. The cycle can then be repeated again.

The RWF-GMAW process can integrate the movement control of the filling metal 138 into the control of the welding process by synchronizing the movement of the filling metal 138 with a waveform of the electrical power. Mechanical retraction of the filler metal 138 can assist in the transfer of metal to maintain a current at a very low level during a short circuit. The heat from the RWF-GMAW process can be greatly reduced due to virtually current-free metal transfer. The RWF-GMAW process can produce only a fraction of the heat compared to a conventional GMAW process. For example, the RWF-GMAW process can produce heat for less than 1 kJ / inch (1 inch = 2.5 cm). Splash levels from the RWF-GMAW process can also be greatly reduced.

The RWF-GMAW process can be applied to welding applications which require a small amount of heat. The RWF-GMAW process can provide less base metal dilution. However, the RWF-GMAW process can be much more complex than a conventional GMAW process. There can be more than 60 adjustable welding parameters to guarantee optimized welding. Some manufacturers can store pre-programmed welding parameters in the DSP 113 of the energy source 111. However, there are no preprogrammed process parameters readily available for welds of austenitic manganese steels, specifically Hadfield manganese steel. Welding parameters may have to be specifically developed for a difficult welding application, for example in a welding application of welded Hadfield manganese steel. Welding parameters can include, for example, a quantity of heat, a current, a voltage, a contact tip distance to the workpiece, a shielding gas flow rate, a wire feed speed, a propagation speed welding, propagation angle or orientation, working angle or orientation, etc.

Figure 6 illustrates a joint geometry of a work piece 150 having a heat-sensitive material to be welded using an RWG-GMAW method according to one embodiment. The work piece 150 may comprise a first piece 151 of metal to be welded to a second piece 152 of metal. The first piece 151 of metal can be made of a material sensitive to heat. According to one embodiment, the heat-sensitive material can comprise a Hadfield manganese steel. Manganese Hadfield steel can have a chemical composition by weight, for example, carbon in the range of 1.00% and 1.40%, manganese in the range of 11% to 14%, silicon in the range 1.00 % maximum, phosphorus 0.10% maximum, sulfur 0.05% maximum, and chromium 1.50% maximum. Manganese Hadfield steel can be forged or cast. The second piece 152 of metal may include a metallic material similar to the Hadfield manganese steel in the first piece 151 of metal. The second piece 152 of metal may include a metallic material which is not similar to the Hadfield manganese steel in the first piece 151 of metal, such as austenitic stainless steel, or carbon steel. Austenitic stainless steel or carbon steel can be plated. Austenitic stainless steel can have grade 304, 304L, 316, 316L, etc. Carbon steel may have a grade SA516.

The first piece 151 of metal having a heat-sensitive material can be positioned horizontally. The second piece 152 of metal can be positioned vertically to form a T-joint geometry. The second piece 152 of metal can be clamped in position before welding. Other types of holding mechanism, such as bond welding of the second piece 152 of metal to the first piece 151 of metal, can also be used. The first piece 151 of metal can have a thickness Th. The thickness T ₂ can be approximately 2.54 cm. The second piece 152 of metal can have a thickness T ₂ . The thickness T ₂ can be equal to approximately 0.32 cm for stainless steel, or to approximately 0.27 cm for carbon steel.

The weld 153 can be carried out on both sides of the T-joint. A dimension of the weld 153 can be approximately 0.43 cm. The weld 153 can be a corner weld. Other types of welds, such as groove welds, can also be used. Support material may not be used at the root of the joint. The welding can be carried out with the work piece 150 at room temperature. The welding position can be horizontal, for example the 2F position according to ASME Section IX Edition 2013. Other types of welding position according to ASME Section IX Edition 2013, such as flat, for example 1F, or vertical positions, for example 3F, can also be used. Post-weld heat treatment may not be performed.

The filler metal 138 can be a stainless steel of ER309 grade, which can belong to the SFA classification 5.9 / 5.9M. Other types of filler metal 138 can also be used, such as 18.8 Mn. The filler metal 138 can also be in the form of a solid wire. A diameter of the filler metal 138 can be between 1.143 mm and 1.575 mm. For example, a diameter of the filler metal 138 may be equal to 0.9 mm.

A protective gas 118 can be inert or semi-inert. A shielding gas 118 may be based on argon or a mixture of argon and C0 ₂ . For example, the shielding gas 118 may be a mixture of 98% argon and 2% C0 ₂ . The flow rate of the shielding gas 118 can be between 0.42 m ³ / h and 1.7 m ³ / h, or between 0.71 m ³ / h and 1.42 m ³ / h, or between 0 , 99 m ³ / h and 1.27 m ³ / h.

Electrical characteristics of the energy source 111 can be a positive direct current electrode. The pulse frequency of the energy source 111 can be 10 Hz.

According to one embodiment, for welding Hadfield manganese steel to austenitic manganese steel, the current can be adjusted between 50 A and 100 A, or between 60 A and 90 A, or between 70 A and 85 A. The voltage can be adjusted between 5 V and 35 V, or between 10 V and 25 V, or between 15 V and 20 V. The amount of heat of the RWF-GMAW process can be adjusted between 0.118 kJ / mm and 1.182 kJ / mm, or between 0.394 kJ / mm and 0.788 kJ / mm, or between 0.552 kJ / mm and 0.63 kJ / mm.

According to one embodiment, for welding Hadfield manganese steel to carbon steel, the current can be adjusted between 50 A and 200 A, or between 125 A and 175 A, or between 130 A and 150 A. The voltage can be adjusted between 5 V and 35 V, or between 15 V and 25 V, or between 18 V and 23 V. The amount of heat of the RWF-GMAW process can be adjusted between 0.118 kJ / mm and 0.985 kJ / mm, or between 0.394 kJ / mm and 0.788 kJ / mm, or between 0.433 kJ / mm and 0.591 kJ / mm.

Welding 153 can be performed using a single pass. Welding 153 can also be carried out using a multiple pass.

According to one embodiment, to weld Hadfield manganese steel to austenitic stainless steel, the speed of movement of the welding of the torch 130 when it performs the welding 153 can be adjusted between 10.16 cm / min and 25.4 cm / min, or between 14.73 cm / min and 15.75 cm / min.

According to one embodiment, for welding Hadfield manganese steel to carbon steel, the speed of movement of the welding torch 130 when it performs welding 153 can be adjusted between 12.7 cm / min and 76.2 cm / min, or between 25.4 cm / min and 50.8 cm / min, or between 35.56 cm / min and 45.72 cm / min. The contact tip distance to work piece 130 can be about 1.11 cm.

FIG. 7 illustrates a diagram in the form of a diagram of a working orientation 155 of a torch 130 when a welding 153 is carried out on a work piece 150. According to one embodiment, the working angle 155 can be between 45 degrees and 65 degrees between the horizontal and the longitudinal axis 154 of the torch 130. For example, the working angle 155 can be approximately 55 degrees between the horizontal and the longitudinal axis 154 of the torch 130.

FIG. 8 illustrates a diagram in the form of a diagram of an angle or orientation 156 of displacement of a torch 130 when a welding 153 is carried out on a work piece 150. According to one embodiment, the angle 156 of displacement can be between 0 and 20 degrees of thrust, which means that the torch 130 is directed towards a direction 157 of displacement and the angle calculated between the vertical and the axis 154 longitudinal of the torch 130 is between 0 and 20 degrees. For example, the angle of movement can be about 10 degrees of thrust.

Figure 9 illustrates a perspective view of a configuration 158 of wire bead of a weld 153 on a work piece 150. A wire bead configuration 158 is a type of weld 153 which can be formed by a straight line movement of a torch as shown by the arrow. FIG. 10 illustrates a perspective view of a pattern 159 of mesh bead of a weld 153 on a work piece 150. A mesh bead pattern 159 is a type of weld 153 which can be formed by a transverse oscillating movement of a torch as shown by the arrow. According to one embodiment, a pattern 159 of mesh bead can be used for welding 153. A pattern 158 of wire bead can also be used for welding 153.

According to one aspect, the proposed method can adjust an RWF-GMAW method for welding heat-sensitive material, for example for welding of manganese steel Hadfield. The proposed RWF-GMAW process can provide much less heat compared to the conventional GMAW process. The low amount of heat can result in a weak base metal dilution and prevent cracking during welding which could result in better weld quality.

According to one aspect, the proposed method provides optimized welding parameters for welding heat-sensitive material using a method

RWF-GMAW. The welding parameters can be controlled in a closed loop by a source 111 of inverter energy controlled by a digitized microprocessor. The proposed process can provide a good quality weld that can be repeated and reliable.

According to one aspect, the proposed method can be applied to an RWF-GMAW method including the Fronius Cold Metal Transfer, the Jetline Controlled Short Circuit, the SKS MicroMig Welding System, the Panasonic Active Wire Process, etc. . Welding can be an automatic operation performed by a robot. Welding can also be a manual operation for small localized welds.

Hadfield manganese steel is a high strength nonmagnetic alloy which is of great interest for generator components in power generation applications. However, due to its heat sensitivity properties, it is very difficult to use Hadfield manganese steel in generator components. Traditionally, gaseous Tungsten Arc Welds with reverse polarity have been used to weld Hadfield manganese steel. However, this process is a manual process and is highly dependent on the capacity of the operator. The quality of the weld is not reliable. The proposed method can allow this material to be welded to several generator parts with good quality. The proposed process may allow welding to be carried out in factory facilities.

Although various embodiments which incorporate the teachings of the present invention have been shown and described in detail here, the skilled person will be able to easily understand and implement many other embodiments which still incorporate these teachings. The invention is not limited in its application to the embodiments given by way of examples and to the construction details and to the arrangements of components provided in the description or illustrated in the drawings. The invention can be realized in the form of other embodiments and can be implemented or be carried out in various ways. It should also be understood that the terminologies and phrasing herein used for the purpose of describing should not be considered as limiting. The use of the terms including, including or having and their variants includes the articles listed after them and their equivalents as well as additional articles. Unless specified or otherwise limited, the terms mounted, connected, supported and coupled and their variants are used in their broad meaning and include direct and indirect arrangements, connections, supports and couplings. In addition, connected and coupled are not limited to physical or mechanical couplings or connections.

List of references: 100: Welding machine 110: Power box 111: Energy source 112: Analog to digital converter (A / D) 113: Digital signal processor (DSP ) 114: Inverter 115: Drive device 116: Metal feeding device filling 117: Gas supply device protection 118: Shielding gas 119: Data bus 120: Control unit 130: Welding torch 131: Driven 132: Power cable 133: Shielding gas hose 134: Gas nozzle 135: Gas shielding 136: Contact tip 137: Distance from contact tip to workpiece (CTWD) 138: Metal filler 139: Bow 140: Solder bath

141: Metal welding 150: Piece of job 151: First metal part 152: Second metal part 153: Welding 154: Longitudinal axis of the torch 155: Angle of job 156: Angle of displacement 157: Direction of travel 158: Reason for wire cord 159: Reason for mesh cord

Claims (10)

1. Welding method for welding a work piece comprising a material sensitive to heat, the method being characterized in that it comprises: supplying electrical energy from a source (111) of energy to a contact tip (136) of a welding torch (130); supplying a filler metal from a filler metal feeder (116) and causing the filler metal to extend through the contact tip to the work piece (150) in which the work piece work includes heat sensitive material; melt part of the work piece to create a weld pool (140) on the work piece (150) by an arc produced between a tip of the filler metal (130) and a surface of the work piece (150) job ; giving the filler metal (138) back and forth to enter and exit the solder bath (140); synchronizing a displacement of the filler metal with an electrical energy waveform; and adjusting a weld setting so that a weld can be made to the workpiece without cracking the heat sensitive material. 2. Welding method according to claim 1, characterized in that the heat-sensitive material comprises Hadfield manganese steel. 3. A welding method according to claim 1, characterized in that the filling metal has a solid wire shape. 4. The welding method according to claim 1, characterized in that the welding parameter comprises an amount of heat, the amount of heat being adjusted to be between 0.118 kJ / mm and 1.182 kJ / mm. 5. A welding method according to claim 1, characterized in that the welding parameter comprises a current, and the current is adjusted to be between 50 A and 200 A. 6. A welding method according to claim 1, characterized in that the welding parameter comprises the voltage, and the voltage is adjusted to be between 5 V and 35 V. 7. The welding method according to claim 1, characterized in that the welding parameter comprises a welding displacement speed, and the welding displacement speed is adjusted to be between 12.7 cm / min and 76.2 cm. / min. 8. A welding method according to claim 1, characterized in that the welding parameter comprises a working angle, and the working angle is adjusted to be between 45 degrees and 65 degrees relative to the horizontal. 9. A welding method according to claim 1, characterized in that the welding parameter comprises a displacement angle, and the displacement angle is adjusted to be between 0 degrees and 20 degrees thrust. 10. The welding method according to claim 1, characterized in that the welding parameter comprises a flow of gas protection, and the flow of gas protection East settled for be including between 0.42 m ³ / h and 1.7 m ³ / h. 11. Device welding for weld a piece (150) working comprising a material sensitive to heat, the welding device comprising: a welding torch (130) having a contact tip; an energy source (111) configured to supply electrical energy to the contact tip of the welding torch; a filler metal supply device (116) configured to supply a filler metal extending through the contact tip to the work piece, the work piece comprising a heat sensitive material, and in which an arc is produced between a tip of the filler metal and a surface of the work piece to create a weld pool (140) on the work piece; and a driving device (115) configured to give the filler metal back and forth movement in and out of the solder bath, wherein the power source (111) comprises a digital signal processor, in which the digital signal processor is configured to send a signal to the device 5 drive so that a displacement of the filler metal is synchronized with a waveform of electrical energy, and in which a weld parameter is set so that a fusion is capable of being performed on the 10 work piece without cracking the heat sensitive material. 1/5 2/5