阅读说明：本技术 稳态磁场耦合激光填丝窄槽修复方法 (Steady-state magnetic field coupling laser wire-filling narrow groove repairing method ) 是由 姚建华 王梁 夏洪超 张群莉 陈智君 吴国龙 于 2019-12-03 设计创作，主要内容包括：稳态磁场耦合激光填丝窄槽修复方法,包括：1)根据待修复工件裂纹深度,加工矩形槽,以去除裂纹区域；对待修复工件进行打磨清洗干燥的初步处理,然后将工件安装在工作台上使得矩形槽开口朝上；定义矩形槽长度方向为X轴方向；2)激光器放置于矩形槽正上方,设激光束方向为Z轴,将送丝头通过夹具安装在激光器上,送丝头与激光器位于XZ平面上；3)励磁线圈缠绕在送丝头上,焊丝作为导磁铁芯,使得送丝头内部的焊丝上产生强度为0.2～0.5T的静态磁场；4)开启激光器,激光束在矩形槽区域沿X轴方向扫描,同时开启送丝机向激光光斑区域送入焊丝,填充焊丝尖端与激光光斑中心间距为0～1mm；停止激光器与送丝机即完成修复过程。(The steady-state magnetic field coupling laser wire-filling narrow groove repairing method comprises the following steps: 1) processing a rectangular groove according to the crack depth of the workpiece to be repaired to remove a crack area; carrying out primary treatment of polishing, cleaning and drying on a workpiece to be repaired, and then mounting the workpiece on a workbench to enable the opening of the rectangular groove to be upward; defining the length direction of the rectangular groove as the X-axis direction; 2) the laser is placed right above the rectangular groove, the direction of a laser beam is set as a Z axis, the wire feeding head is installed on the laser through the clamp, and the wire feeding head and the laser are located on an XZ plane; 3) the excitation coil is wound on the wire feeding head, and the welding wire is used as a magnetic conductive iron core, so that a static magnetic field with the strength of 0.2-0.5T is generated on the welding wire in the wire feeding head; 4) starting a laser, scanning a laser beam in the rectangular groove area along the X-axis direction, simultaneously starting a wire feeder to feed welding wires into a laser spot area, wherein the distance between the tip of the filler welding wire and the center of the laser spot is 0-1 mm; and stopping the laser and the wire feeder to finish the repairing process.)

1. The steady-state magnetic field coupling laser wire-filling narrow groove repairing method comprises the following steps:

(1) according to the crack depth of a workpiece to be repaired, machining a rectangular groove with the depth being more than or equal to 4mm of the crack depth by adopting a mechanical machining method, wherein the width of the rectangular groove is 2-4 mm so as to remove a crack area; carrying out primary treatment of polishing, cleaning and drying on a workpiece to be repaired, and then mounting the workpiece on a workbench to enable the opening of the rectangular groove to be upward; the length direction of the rectangular groove is defined as the X-axis direction.

(2) The laser is placed right above the rectangular groove, the direction of the laser beam is set to be a Z axis, the wire feeding head is installed on the laser through the clamp, the wire feeding head and the laser are located on an XZ plane, and the axial included angle between the filler wire and the laser beam is 30-70 degrees;

(3) the exciting coil is wound on the wire feeding head, the welding wire is used as a magnetic conductive iron core, the number of turns of the selected exciting coil is 100-400, and 5-15A direct current is introduced, so that a static magnetic field with the strength of 0.2-0.5T is generated on the welding wire in the wire feeding head;

(4) starting a laser, scanning a laser beam in the rectangular groove area along the X-axis direction, simultaneously starting a wire feeder to feed welding wires into a laser spot area, wherein the distance between the tip of the filler welding wire and the center of the laser spot is 0-1 mm; and stopping the laser and the wire feeder to finish the repairing process.

2. The steady-state magnetic field coupling laser filament-filling narrow groove repairing method according to claim 1, characterized in that: the diameter of the light spot is 2 mm-4 mm, the wire feeding speed is 10 mm/s-25 mm/s, the diameter of the welding wire is 0.8 mm-2 mm, the laser power is 1 kw-3 kw, and the scanning speed is 4 mm/s-12 mm/s.

3. The steady-state magnetic field coupling laser filament-filling narrow groove repairing method according to claim 1, characterized in that: the wire feeding head is made of non-ferromagnetic materials, and the welding wire is made of ferromagnetic materials.

Technical Field

The invention relates to a steady-state magnetic field coupling laser wire-filling narrow groove repairing method.

Background

The laser remanufacturing technology is a general name of technology for remanufacturing waste parts by using a high-energy laser beam as an energy source. In order not to damage the substrate too much or repair internal cracks, milling grooves with high aspect ratio are needed to meet the repair performance requirements, and finally, metal with the same material or similar performance is filled in the milling groove area by using a laser remanufacturing technology. However, when the metal powder is used as a filler for repair, there are defects such as difficulty in feeding the powder into a narrow groove, porosity due to a hollow powder, and melting defects. The laser wire filling welding has small heat influence and small welding deformation, and the welding wire has certain rigidity, so that the filling metal can be directly fed into the bottom of the narrow groove, and the repair of the extremely narrow groove can be realized. However, laser filler wire bonding also has some problems: for example, defects such as inclusion pores are easy to remain in the welding seam, and the performance after repair is influenced; the adjustment of the simple laser process parameters cannot control the movement direction of fluid in the molten pool, thereby achieving the purpose of controlling the structure and the performance of a solidified layer.

Aiming at the problems, domestic and foreign scholars regulate and control laser welding by using an external magnetic field mode. Bachmann et al scholars utilize a steady magnetic field provided by a permanent magnet to regulate and control the aluminum alloy full-depth fusion welding. Research shows that the steady-state magnetic field can generate Lorentz force opposite to the convection direction of a molten pool when the movement direction of the conductive fluid is not parallel to the magnetic field direction, so that the flow of the molten pool is inhibited, the cross section and the surface appearance of a welding seam are further improved, and the splashing phenomenon in the welding process is inhibited. Asai et al found that alternating magnetic fields can reduce the equiaxed grain size and reduce the relative volume of columnar grain regions. Domestic Liuhong xi scholars and other scholars refine the tissues of the laser cladding layer by using an alternating magnetic field. The device disclosed in the above documents does not have a stable magnetic field for laser wire filling welding, and the magnetic field generated by the device acts on the whole substrate, which cannot act on the molten pool precisely, and is difficult to be applied to parts with complex shapes such as shaft curves.

Disclosure of Invention

The invention provides a steady-state magnetic field coupling laser wire feeding narrow groove repairing method and a steady-state magnetic field coupling laser wire feeding narrow groove repairing device for overcoming the defects in the prior art, wherein the method comprises the implementation steps of the method and a magnetic field device, and the magnetic field and the wire feeding device are coupled to achieve the purpose of regulating and controlling the welding process.

The invention adopts the following technical scheme:

a steady-state magnetic field coupling laser wire-filling narrow groove repairing method comprises the following steps:

(1) according to the crack depth of a workpiece to be repaired, machining a rectangular groove with the depth being more than or equal to 4mm of the crack depth by adopting a mechanical machining method, wherein the width of the rectangular groove is 2-4 mm so as to remove a crack area; carrying out primary treatment of polishing, cleaning and drying on a workpiece to be repaired, and then mounting the workpiece on a workbench to enable the opening of the rectangular groove to be upward; the length direction of the rectangular groove is defined as the X-axis direction.

(2) The laser is placed right above the rectangular groove, the direction of the laser beam is set to be a Z axis, the wire feeding head is installed on the laser through the clamp, the wire feeding head and the laser are located on an XZ plane, and the axial included angle between the filler wire and the laser beam is 30-70 degrees;

(3) the exciting coil is wound on the wire feeding head, the welding wire is used as a magnetic conductive iron core, the number of turns of the selected exciting coil is 100-400, and 5-15A direct current is introduced, so that a steady-state magnetic field with the strength of 0.2-0.5T is generated on the welding wire in the wire feeding head;

(4) starting a laser, scanning a laser beam in the rectangular groove area along the X-axis direction, simultaneously starting a wire feeder to feed welding wires into a laser spot area, wherein the distance between the tip of the filler welding wire and the center of the laser spot is 0-1 mm; and stopping the laser and the wire feeder to finish the repairing process.

Preferably, the diameter of the light spot is 2 mm-4 mm, the wire feeding speed is 10 mm/s-25 mm/s, the diameter of the welding wire is 0.8 mm-2 mm, the laser power is 1 kw-3 kw, and the scanning speed is 4 mm/s-12 mm/s.

The wire feeding head is made of non-ferromagnetic materials, and the welding wire is made of ferromagnetic materials. The invention mainly generates a steady magnetic field on the welding wire through the exciting coil and guides the steady magnetic field into a molten pool through the welding wire. The static magnetic field can generate Lorentz force opposite to the convection direction of the molten pool when the movement direction of the conductive fluid is not parallel to the magnetic field direction, and the flow of the molten pool is inhibited, so that the purposes of regulating and controlling a solidification structure, improving the appearance of a welding seam, reducing the number of defects and the like are achieved.

The method of the invention has the following advantages:

(1) the invention attaches the magnet exciting coil to the wire feeding head and takes the welding wire as the iron core, so that the steady magnetic field can accurately and stably act on the molten pool area and can be suitable for parts with different shapes, such as shafts, curved surfaces and the like.

(2) The magnetic field device adopted by the invention is simple, the cost is low, the original wire feeding head is simply modified, and extra equipment is not required to be purchased.

(3) The invention adopts a mode of external energy field to regulate and control the solidification structure, reduces the number of defects, does not need to repeatedly carry out laser process research, and simplifies the repair process.

Drawings

FIG. 1 is a schematic view of a steady state magnetic field coupled laser wire feed slot repair apparatus for carrying out the method of the present invention.

FIG. 2 is a partial cross-sectional view of the field coil section of a steady-state magnetic field coupled laser wire feed slot repair apparatus for carrying out the method of the present invention.

FIG. 3 is a diagram of a fixture for a steady state magnetic field coupled laser wire feed slot repair device for practicing the method of the present invention

FIG. 4 is a stud drawing of a steady state magnetic field coupled laser wire feed slot repair device fixture implementing the method of the present invention

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings

A steady-state magnetic field coupling laser wire-filling narrow groove repairing method comprises the following steps:

(1) according to the crack depth of the workpiece 5 to be repaired, a rectangular groove with the depth more than or equal to 4mm of the crack depth is machined by a mechanical machining method, and the width of the rectangular groove is 2 mm-4 mm so as to remove a crack area; carrying out primary treatment of polishing, cleaning and drying on the workpiece 5 to be repaired, and then installing the workpiece 5 to be repaired on a workbench to enable the opening of the rectangular groove to be upward; the length direction of the rectangular groove is defined as the X-axis direction.

(2) The laser 2 is placed right above the rectangular groove, the direction of the laser beam is set to be a Z axis, the wire feeding head 4 is installed on the laser 2 through the clamp 3, the wire feeding head 4 and the laser 2 are located on an XZ plane, and the included angle between the filler wire and the axis of the laser beam is 30-70 degrees;

(3) the exciting coil 6 is wound on the wire feeding head 4, the welding wire is used as a magnetic conductive iron core, the number of turns of the selected exciting coil is 100-400 turns, and 10-20A direct current is introduced, so that a steady-state magnetic field with the strength of 0.2-0.5T is generated on the welding wire in the wire feeding head;

(4) starting a laser 2, scanning a laser beam in the rectangular groove area along the X-axis direction, simultaneously starting a wire feeder 1 to feed welding wires into a laser spot area, wherein the distance between the tips of the filled welding wires and the center of the laser spots is 0-1 mm; the repair process is completed by stopping the laser 2 and the wire feeder 1.

The laser repair process comprises the following steps: the diameter of a light spot is 2 mm-4 mm, the wire feeding speed is 10 mm/s-25 mm/s, the diameter of a welding wire is 0.8 mm-2 mm, the laser power is 1 kw-3 kw, and the scanning speed is 4 mm/s-12 mm/s.

The wire feeding head is made of non-ferromagnetic materials, and the welding wire is made of ferromagnetic materials.

The equipment for implementing the method comprises a laser 2, a wire feeder 1, a wire feeding head 4 and a clamp 3 which is used for fixing the wire feeding head and adjusting the position of the wire feeding head;

the wire feeding head 4 is fixed on the laser 2 through the clamp 3, the exciting coil 6 is arranged outside the wire feeding head 4, direct current is introduced into the exciting coil 6, so that a stable magnetic field is generated on the welding wire, and the stable magnetic field is accurately fed into a molten pool area through the welding wire;

the wire feeding head 4 is made of non-ferromagnetic materials, and the welding wire is made of ferromagnetic materials.

The clamp 3 comprises a bottom plate 7 for fixing the clamp on the laser, a first adjusting plate 9 along the X-axis direction, a second adjusting plate 13 along the Y-axis direction and a first stud 14 along the Z-axis direction;

the base plate 7 is fixed on the laser, and two sides of the base plate 7 are respectively connected with a first adjusting plate 9; one end of the first adjusting plate 9 is fixed on the bottom plate 7 through a screw, a first through groove extending along the X-axis direction is formed in the first adjusting plate 9, a first bolt 11 is slidably arranged in the first through groove, the bottom end of the first bolt 11 is connected with a second adjusting plate 13, and a first nut 12 capable of screwing the first adjusting plate 9 and the second adjusting plate 13 together is arranged at the top end of the first bolt 11, so that the second adjusting plate 13 can move or be positioned on the first adjusting plate 9 along the X-axis direction; a second through groove extending along the Y-axis direction is formed in the middle of the second adjusting plate 13, a first stud 14 penetrates through the second through groove, second nuts 10 are arranged on the upper side and the lower side of the second through groove of the first stud 14, a structure with double nuts on the upper side and the lower side is adopted, the stud 14 and the second adjusting plate 13 are screwed tightly, and the stud 14 can move and be positioned in the through groove along the Y-axis direction and the Z-axis direction; the lower ends of the two first studs 14 are connected with sleeves, the two sleeves are threaded on the second bolt 15 in the Y direction, an earring of the wire feeding head shell is clamped between the two sleeves, the earring of the wire feeding head shell is also threaded on the second bolt 15, and the second bolt 15 and the third nut 16 are screwed tightly, so that the wire feeding head 4 can rotate and be positioned in an XZ plane around the second bolt 15.

The embodiments described in this specification are merely illustrative of implementations of the inventive concept and the scope of the present invention should not be considered limited to the specific forms set forth in the embodiments but rather by the equivalents thereof as may occur to those skilled in the art upon consideration of the present inventive concept.