1. The relationship between welding process stability and specification matching
1.1 On the premise of ensuring good peripheral system (wire feeding and conductive), suggestions are as follows:
When I <200A, U = (14 0.05I) ± 2 V
When I> 200A (especially with extension line), the voltage is slightly higher
U=(16 0.05I)±2V
★Main features of the best welding specification:
A. The weld is well formed. B. The welding process is stable and the splash is small. c. Hear the sound of sand during welding. d. When welding, we can see that the pointer of ammeter and voltmeter of welding machine is stable and the swing is small.
★Adjustment steps of the best welding specification:
A. Choose the diameter of welding wire, gas flow and welding current according to the thickness of workpiece and welding position.
B. Try welding on the test plate, and adjust the welding voltage and Arc Thrust carefully according to the selected welding current. The best welding voltage is generally 1 ~ Between 2 v.
C. Adjust the welding current, welding voltage and gas flow properly according to the formation condition of welding seam on the test plate to reach the best welding specification.
D. during the formal welding process on workpieces, the welding circuit and the voltage drop caused by the contact resistance should be paid attention to, and the welding voltage should be adjusted (fine-tuned) in time to ensure the stability of the welding process (for the situation of large workpieces).
1.2 Welding phenomena with poor specification matching and its elimination
① When the terminal of the welding wire always has dripping metal balls, and the transition frequency is low, this situation shows
High welding voltage, increase wire feeding speed (welding current) or reduce welding voltage to solve the problem.
② When the dry stretch is shorter, it can be welded normally, and if it is longer, the problem of top wire will appear. It indicates that the welding voltage is low
, Solve by reducing wire feeding speed (welding current) or increasing welding voltage.
③ Pay attention to the status of the knob on the panel:
In general, we will adjust the thrust knob to the right by 2 according to the standard scale ~ 3 grids. When the current is too large, it is suggested to increase the thrust knob according to the stability of the welding process. For the small current of the fine welding wire Φ0.8, Φ1.0 (Φ0.8 I <80A, Φ1.0 I <100A ), arc thrust can be properly reduced,
This is good for the flexibility of the arc.
④ Diameter switch of welding wire
The diameter switch of the welding wire must be chosen correctly, which should be consistent with the diameter of the welding wire used.
2. The relationship between Weld casting and welding specification
2.1 The influence of welding specification and plate thickness on molding
① General I = (20 ~ 30) δ, if δ> 6mm, multi-layer or multi-channel and multi-layer welding should be adopted to ensure good molding.
② If the current is small, it is easy to appear that the weld seam can not be spread out and become stacked, especially the angular weld seam without groove.
③ If the current is too large, the phenomenon of welding leakage of workpieces is easy to occur.
2.2 The influence of welding specification selection on Weld casting and weld quality
① For the weld seam of the groove opening, generally the bottom layer adopts 100 ~ 120A/18.0 V or so. In this way, it can not only ensure the reverse forming of the weld path, but also avoid welding through the workpiece with too much current.
② The welding current of the filling layer can be chosen according to the welding position, and the range is 150 ~ Between 250A. In this way, the welding efficiency is guaranteed as well as the good fusing between welding channels.
③ The cover surface layer generally reduces the welding current appropriately, 150 ~ 160A is OK, so as to ensure the beautiful appearance of the surface.
④ Control the moving speed of welding. When the current is high, move faster. When the current is small, swing properly.
3. The relationship between preset and actual display
3.1 preset voltage range, under normal circumstances 15 ~ 48V
Preset current scale 30 ~ 280
3.2 The relationship between the preset voltage and the actual voltage is ± 1 V (assessed under the agreed load)
3.3 The relationship between the preset current scale and the actual current has a great relationship with the lengthening line, the dry extension and the diameter of the welding wire. The relationship between the scale and the actual current can be expressed as: I actual = ×k
IMax: the maximum current output by the wire diameter power supply
K: preset current scale value I actual: actual welding current
For standard configuration: 10 m/50mm2 cable, dry extension is about 15mm in use.
