A cold welding repair method for workpiece sealing surface

Abstract

The invention discloses a cold welding repair method for a workpiece sealing surface, comprising the following steps: step 1: cleaning the worn part of the workpiece sealing surface to be repaired before welding; step 2: spot welding the welding wire on the worn part of the workpiece sealing surface, fixing the position of the welding wire and the workpiece; step 3: cold welding on one side of the welding wire, the welding wire on the welding side is melted on the worn part, and the welding wire on the unwelded side is not melted; step 4: removing the welding wire on the unwelded side, and grinding the welding area, so that the repair surface and the substrate surface are flush, and the repair of the sealing surface is completed. The cold welding repair method of the invention uses the welding wire on the unwelded side to perform temperature compensation on the welding part, and compared with the traditional cold welding repair method, the shrinkage mark after thermal expansion and contraction can be significantly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of precision repair welding, and in particular to a cold welding repair method for a workpiece sealing surface. Background Art

[0002] High-precision metal repair welding uses welding wire as the repair material. The high heat energy generated by the instantaneous discharge of the cold welding machine's micro-electricity is used to melt the special welding wire onto the damaged part of the workpiece and firmly fuse it with the original substrate. After welding, only a small amount of post-processing such as grinding and polishing is required, which is particularly suitable for workpiece repair.

[0003] When the sealing surface of the workpiece is worn, very tiny pits will be produced. The existing repair method is to place the welding wire on the worn area, perform cold welding on the welding wire, melt the entire welding wire on the worn area, and then grind to remove the excess protruding part. After welding, shrinkage marks will be produced due to thermal expansion and contraction. The existing cold welding repair method produces two shrinkage marks. Summary of the invention

[0004] 1. Technical problem to be solved: In view of the above technical problem, the present invention provides a cold welding repair method for a workpiece sealing surface.

[0005] 2. Technical solution:

[0006] A cold welding repair method for a workpiece sealing surface comprises the following steps:

[0007] Step 1: Clean the worn area of ​​the sealing surface of the workpiece to be repaired before welding;

[0008] Step 2: Spot weld the welding wire to the worn part of the sealing surface of the workpiece to fix the position of the welding wire and the workpiece;

[0009] Step 3: Cold welding is performed on one side of the welding wire. The welding wire on the welding side is melted at the worn area, and the welding wire on the unwelded side is not melted;

[0010] Step 4: Remove the welding wire on the unwelded side and grind the welding area to make the repaired surface flush with the substrate surface to complete the repair of the sealing surface.

[0011] Furthermore, the diameter of the welding wire is 0.8mm-2mm, the pulse current of the cold welding machine is 20kA-60kA, the pulse time is 50-70ms, and the pulse frequency is 2Hz.

[0012] Furthermore, the specific steps of step 1 include polishing the part of the workpiece to be repaired, removing the oxide layer, and using acetone or anhydrous ethanol to remove surface oil stains.

[0013] Furthermore, the welding wire is a nickel-based welding wire or a cobalt-based welding wire.

[0014] Furthermore, the specific steps of step 4 include using a 260-mesh sandpaper flap wheel for grinding.

[0015] 3. Beneficial effects:

[0016] The cold welding repair method of the present invention performs temperature compensation on the welding point through the welding wire on the unwelded side. Compared with the traditional cold welding repair method, the shrinkage mark after thermal expansion and contraction can be significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The surface image of the workpiece after spot welding with welding wire in step 2 of embodiment 1 of the present invention;

[0018] Figure 2 The surface image of the workpiece after single-side cold welding of the welding wire in step 3 of embodiment 1 of the present invention;

[0019] Figure 3 The surface image of the workpiece after polishing in step 4 of embodiment 1 of the present invention;

[0020] Figure 4 The surface image of the workpiece after spot welding with welding wire in step 2 of embodiment 2 of the present invention;

[0021] Figure 5 This is the surface image of the workpiece after single-side cold welding of the welding wire in step 3 of embodiment 2 of the present invention;

[0022] Figure 6 The surface image of the workpiece after polishing in step 4 of embodiment 1 of the present invention;

[0023] Figure 7 This is the surface image of the workpiece after cold welding directly above the welding wire in step 2 of comparative example 1;

[0024] Figure 8 This is the surface image of the workpiece after polishing in step 3 of comparative example 1. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings.

[0026] As attached Figure 1 To Attachment Figure 6 As shown,

[0027] Embodiment 1:

[0028] A cold welding repair method for a workpiece sealing surface comprises the following steps:

[0029] Step 1: Grind the part to be repaired to remove the oxide layer, and use acetone to remove surface oil stains;

[0030] Step 2: Spot weld a nickel-based welding wire with a diameter of 1 mm on the worn area of ​​the sealing surface of the workpiece to fix the position of the welding wire and the workpiece;

[0031] Step 3: Cold welding is performed on one side of the welding wire. The pulse current of the welding machine is 30kA, the pulse time is 70ms, and the pulse frequency is 2Hz. The welding wire on the welding side is melted at the worn area, and the welding wire on the unwelded side is not melted.

[0032] Step 4: Remove the welding wire on the unwelded side and use a 260-grit sandpaper flap wheel to grind the welding area so that the repair surface is flush with the base surface to complete the repair of the sealing surface.

[0033] The shrinkage marks after welding are significantly reduced. After cold welding repair, the plane dial indicator shows: 0.001-0.005mm, which meets the requirements.

[0034] Embodiment 2:

[0035] A cold welding repair method for a workpiece sealing surface comprises the following steps:

[0036] Step 1: Grind the part to be repaired to remove the oxide layer, and use acetone to remove surface oil stains;

[0037] Step 2: Spot weld a nickel-based welding wire with a diameter of 2 mm on the worn area of ​​the sealing surface of the workpiece to fix the position of the welding wire and the workpiece;

[0038] Step 3: Cold welding is performed on one side of the welding wire. The pulse current of the welding machine is 60kA, the pulse time is 70ms, and the pulse frequency is 2Hz. The welding wire on the welding side is melted at the worn area, and the welding wire on the unwelded side is not melted;

[0039] Step 4: Remove the welding wire on the unwelded side and use a 260-grit sandpaper flap wheel to grind the welding area so that the repair surface is flush with the base surface to complete the repair of the sealing surface.

[0040] The shrinkage marks after welding are significantly reduced. After cold welding repair, the plane dial indicator shows: 0.001-0.005mm, which meets the requirements.

[0041] Embodiment 3:

[0042] A cold welding repair method for a workpiece sealing surface comprises the following steps:

[0043] Step 1: Grind the part to be repaired to remove the oxide layer, and use acetone to remove surface oil stains;

[0044] Step 2: Spot weld a nickel-based welding wire with a diameter of 0.8 mm on the worn area of ​​the sealing surface of the workpiece to fix the position of the welding wire and the workpiece;

[0045] Step 3: Cold welding is performed on one side of the welding wire. The pulse current of the welding machine is 28kA, the pulse time is 50ms, and the pulse frequency is 2Hz. The welding wire on the welding side is melted at the worn area, and the welding wire on the unwelded side is not melted;

[0046] Step 4: Remove the welding wire on the unwelded side and use a 260-grit sandpaper flap wheel to grind the welding area so that the repair surface is flush with the base surface to complete the repair of the sealing surface.

[0047] The shrinkage marks after welding are significantly reduced. After cold welding repair, the plane dial indicator shows: 0.001-0.005mm, which meets the requirements.

[0048] Embodiment 4:

[0049] A cold welding repair method for a workpiece sealing surface comprises the following steps:

[0050] Step 1: Grind the part to be repaired to remove the oxide layer, and use acetone to remove surface oil stains;

[0051] Step 2: Spot weld a cobalt-based welding wire with a diameter of 1.6 mm on the worn area of ​​the sealing surface of the workpiece to fix the position of the welding wire and the workpiece;

[0052] Step 3: Cold welding is performed on one side of the welding wire. The pulse current of the welding machine is 55kA, the pulse time is 60ms, and the pulse frequency is 2Hz. The welding wire on the welding side is melted at the worn area, and the welding wire on the unwelded side is not melted.

[0053] Step 4: Remove the welding wire on the unwelded side and use a 260-grit sandpaper flap wheel to grind the welding area so that the repair surface is flush with the base surface to complete the repair of the sealing surface.

[0054] The shrinkage marks after welding are significantly reduced. After cold welding repair, the plane dial indicator shows: 0.001-0.005mm, which meets the requirements.

[0055] Embodiment 5:

[0056] A cold welding repair method for a workpiece sealing surface comprises the following steps:

[0057] Step 1: Grind the part to be repaired to remove the oxide layer, and use acetone to remove surface oil stains;

[0058] Step 2: Spot weld a cobalt-based welding wire with a diameter of 0.6 mm on the worn area of ​​the sealing surface of the workpiece to fix the position of the welding wire and the workpiece;

[0059] Step 3: Cold welding is performed on one side of the welding wire. The pulse current of the welding machine is 20kA, the pulse time is 50ms, and the pulse frequency is 2Hz. The welding wire on the welding side is melted at the worn area, and the welding wire on the unwelded side is not melted;

[0060] Step 4: Remove the welding wire on the unwelded side and use a 260-grit sandpaper flap wheel to grind the welding area so that the repair surface is flush with the base surface to complete the repair of the sealing surface.

[0061] The shrinkage marks after welding are significantly reduced. After cold welding repair, the plane dial indicator shows: 0.001-0.005mm, which meets the requirements.

[0062] Comparative Example 1:

[0063] A cold welding repair method for a workpiece sealing surface comprises the following steps:

[0064] Step 1: Grind the part to be repaired to remove the oxide layer, and use acetone to remove surface oil stains;

[0065] Step 2: Cold welding is performed directly on the welding wire to melt the entire welding wire onto the worn area. The pulse current of the welding machine is 20kA, the pulse time is 50ms, and the pulse frequency is 2Hz.

[0066] Step 3: Use a 260-grit sandpaper flap wheel to grind the welding area to make the repair surface flush with the base surface to complete the repair of the sealing surface.

[0067] There are two shrinkage marks after welding, and the plane dial indicator shows: 0.005-0.01mm.

[0068] It should be noted that the model of the cold welding machine in Examples 1-5 and Comparative Example 1 is Shengzao Jidian SZ-1800.

[0069] Although the present invention has been disclosed as above in terms of preferred embodiments, they are not intended to limit the present invention. Anyone skilled in the art can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined by the claims of this application.

Claims

1. A cold welding repair method for a workpiece sealing surface, characterized in that: The following steps are involved: Step 1: Clean the worn area of ​​the sealing surface of the workpiece to be repaired before welding; Step 2: Spot weld the welding wire to the worn part of the sealing surface of the workpiece to fix the position of the welding wire and the workpiece; Step 3: Cold welding is performed on one side of the welding wire. The welding wire on the welding side is melted at the worn area, and the welding wire on the unwelded side is not melted; Step 4: Remove the welding wire on the unwelded side and grind the welding area to make the repaired surface flush with the substrate surface to complete the repair of the sealing surface.

2. A cold welding repair method for a workpiece sealing surface according to claim 1, characterized in that: The specific steps of step 1 include grinding the part of the workpiece to be repaired to remove the oxide layer, and using acetone or anhydrous ethanol to remove surface oil stains.

3. A cold welding repair method for a workpiece sealing surface according to claim 2, characterized in that: The welding wire is a nickel-based welding wire or a cobalt-based welding wire.

4. A cold welding repair method for a workpiece sealing surface according to claim 3, characterized in that: The specific steps of step 4 include grinding with a 260-grit sandpaper flap wheel.

Images