Vacuum electron beam welding method for magnesium alloy component

A technology of vacuum electron beam and welding method, applied in electron beam welding equipment, welding equipment, metal processing equipment and other directions, can solve problems such as inability to eliminate defects, and achieve good appearance, high welding quality consistency, and high welding yield. Effect

Active Publication Date: 2020-08-18

CHINA WEAPON SCI ACADEMY NINGBO BRANCH

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AI-Extracted Technical Summary

Problems solved by technology

This process applies structure-loaded ultrasonic energy with a certain frequency and amplitude during the vacuum electron beam welding process. The ultrasonic frequency is 20-50kHz and the amplitude is 5-40μm. Continuous oscillation can effect...

Abstract

The invention relates to a vacuum electron beam welding method for a magnesium alloy component. The method is characterized by comprising the following steps: (1) selecting a welding part; (2) cleaning the welding part, specifically, wiping and cleaning a magnesium alloy blank and a complete butt joint, and removing an oil film, a water film and organic impurities on the surface to be welded; (3)performing assembling; (4) adopting vacuum electron beam welding; and (5) performing circumferential seam welding. According to the vacuum electron beam welding method, a welding joint form, welding steps, technological parameters and welding defect control are given, air holes in the surface and the subsurface of a welding seam are eliminated, welding defects such as air holes in the welding seam, air holes in the root, arc extinguishing air holes and cold shut can be effectively controlled, in addition, the air holes in the welding seam and the arc extinguishing air holes are dispersedly distributed, the diameter of a single air hole is small, other welding defects such as cracks and slag inclusion do not exist in the welding seam, and the circumferential welding seam is good in appearance forming, consistent in welding quality and high in welding yield.

Application Domain

Electron beam welding apparatus

Technology Topic

Vacuum electronicsSeam welding +9

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Examples

Experimental program(3)

Example Embodiment

[0034] Example one:

[0035] Such as Figure 1 to Figure 3 As shown, the vacuum electron beam welding method of magnesium alloy components of the embodiment of the present invention includes the following steps:

[0036] 1) Selection of welded parts: the welded joint adopts a complete butt joint and a round magnesium alloy blank; in this embodiment, electron beam welding is performed on 20 circular magnesium alloy blanks with an outer diameter of 130mm and an inner diameter of 20mm;

[0037] 2) Cleaning the welded parts: Wipe and clean the magnesium alloy blanks and complete butt joints. Use a clean white gauze dipped in acetone to wipe and clean the weldments to remove the oil film, water film and organic impurities on the surface to be welded. The surface is not allowed to be touched and recontaminated;

[0038] 3) Assembly: After cleaning, all welded parts are assembled and welded, and special tooling fixtures are used for assembly during assembly. The assembly gap is less than 0.1mm, and penetration is required;

[0039] 4) A 60kV medium voltage CNC electron beam welding machine is used for vacuum electron beam welding. The welding conditions are as follows:

[0040] The best working voltage of acceleration voltage is 57~60kV, rated voltage is 60kV; welding speed V 0 600mm/min~650mm/min; select subsurface focus, focus current I during welding 0 2.60A~2.65A; electron beam current L 0 110mA~115mA; vacuum degree≤5×10 -4 mbar; see Table 1 for details;

[0041] Table 1 Electron beam welding process parameters

[0042]

[0043] But in this embodiment, the welding vacuum degree is 4×10 -4 mbar, welding speed V 0 Using 630mm/min, electron beam current L 0 Using 112.0mA, focusing current I 0 Use 2.63A.

[0044] 5) Circumferential weld: the electron gun does not move, and the magnesium alloy blank component rotates to form an annular weld bead. The annular weld bead is the circumferential weld; the annular weld bead includes arc starting section, welding section and arc receiving section in sequence along the circumferential direction. The arc starting section is the arc section corresponding to 0° to 30°, the welding section is the arc section corresponding to 30° to 390°, and the end section of the welding section overlaps the starting arc section, the ending arc section It is the arc segment corresponding to 390° to θ. The arc-finishing section overlaps with the welding section, and the angle θ=445°~450°. In this embodiment, the angle θ=450°, that is, in this embodiment The magnesium alloy component of the steel is rotated 1.25 times in the circumferential direction, so that the end of the welding section overlaps with the arc-starting section, and the arc-finishing section overlaps with the part of the welding section.

[0045] Such as image 3 As shown, the arc starting section is on the arc section of 0°~15°, and the welding speed gradually increases from 0mm/min to V 0 , The arc starting section is on the arc section of 15°~30°, and the welding speed is maintained at V 0; The welding speed of the welding section is maintained at V 0; The welding speed of the arc closing section is determined by V 0 Gradually and continuously decay to 0mm/min. Such as figure 1 As shown, during the arc starting process of the arc starting section, the electron beam current gradually increases from 0mA to L 0 =112mA; the electron beam current of the welding section is kept at L 0 , The electron beam current in the arc receiving section is determined by L 0 Attenuate gradually to 0mA continuously. Such as figure 2 As shown, the focus current of the arc starting section and the welding section is maintained as I 0 , The focus current of the arc closing section is determined by I 0 Continuously increase to I 1 , I 1 =3.30A~3.35A, in this embodiment, I 1 =3.33A.

[0046] The weld penetration depth of the magnesium alloy component obtained by the above vacuum electron beam welding method is 55mm-60mm, and the weld surface and subsurface have no pores, and the pores inside the weld and the arc are dispersed and the diameter of a single pore is less than 1.2mm. There are no other welding defects such as cracks, slag inclusions, etc. in the weld, which means that the welding quality is better while obtaining a larger penetration depth.

[0047] Welds with a penetration depth of 55mm prepared by conventional electron beam welding methods, such as Figure 4 As shown, there are a large number of root nail tip pores in magnesium alloy welds, and some large internal pores; Figure 5 As shown, the welding seam with a penetration depth of 55mm prepared by the welding method of this embodiment has nail tip defects and internal pores at the root and figure 1 Compared with well controlled, the welding quality is better.

Example Embodiment

[0048] Embodiment two:

[0049] The difference between this embodiment and the first embodiment above is only: 1) Choose 20 magnesium alloy blanks with an outer diameter of 140mm and an inner diameter of 20mm; 2) Welding speed V 0 Use 600mm/min, electron beam current L 0 Using 115.0mA, focusing current I 0 Using 2.65A, focus current I 1 = 3.35A.

[0050] The weld penetration depth of the magnesium alloy component obtained by the above vacuum electron beam welding method is 55mm-60mm, and the weld surface and subsurface have no pores, and the pores inside the weld and the arc are dispersed and the diameter of a single pore is less than 1.2mm. There are no other welding defects such as cracks, slag inclusions, etc. in the weld, which means that the welding quality is better while obtaining a larger penetration depth.

Example Embodiment

[0051] Embodiment three:

[0052] The difference between this embodiment and the first embodiment above is only: 1) Choose 20 magnesium alloy blanks with an outer diameter of 140mm and an inner diameter of 20mm; 2) Welding speed V 0 Using 650mm/min, electron beam current L 0 Using 110.0mA, focusing current I 0 Using 2.60A, focusing current I 1 = 3.30A.

[0053] The weld penetration depth of the magnesium alloy component obtained by the above vacuum electron beam welding method is 55mm-60mm, and the weld surface and subsurface have no pores, and the pores inside the weld and the arc are dispersed and the diameter of a single pore is less than 1.2mm. There are no other welding defects such as cracks, slag inclusions, etc. in the weld, which means that the welding quality is better while obtaining a larger penetration depth.

PUM

Property	Measurement	Unit
Penetration	55.0 ~ 60.0	mm
The inside diameter of	3.0 ~ 20.0	mm

Description & Claims & Application Information

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Classification and recommendation of technical efficacy words

High consistency of welding quality
well formed appearance

Dual-robot cooperation welding and detection apparatus control system

ActiveCN107015535Ahigh degree of automationHigh consistency of welding quality

Owner:ZHEJIANG UNIV

Vacuum electron beam welding method for magnesium alloy component

AI-Extracted Technical Summary

Problems solved by technology

Abstract

Image

Examples

Example Embodiment

Example Embodiment

Example Embodiment

PUM

Description & Claims & Application Information

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