When the short-circuit transition current is large (100 ~ 160A), the composite welding laser power is 100 ~ 700W, located in the thermal conduction welding mode area, the role of the laser is mainly to increase the stability of the welding process and reduce the splash of the welding process. Fig. 10 is a weld forming of a stainless steel sheet (thickness: 1.5 mm) in lap welding, the welding conditions are a laser power of 700 W, an arc voltage of 16 to 17 V, a welding current of 110 to 120 A, and a welding speed of 2 m/min.
When the short-circuit transition current is large (100-160A), the hybrid welding laser power is 900-2000W, which is located in the deep-fusion welding mode area. The combination of laser and short-circuit transition MAG arc is characterized by significantly increasing the penetration depth and depth of the weld. This feature makes it possible to reduce the groove angle and improve the welding efficiency of the plate in multi-layer and multi-pass welding. Figure 11 shows a comparison of weld bead formation with MAG welding and laser + short-circuit transition MAG welding with carbon steel (thickness 10mm). When the welding condition is MAG welding, the groove angle is 60°, the arc voltage is 19-22 V, the welding current is 165-190 A, the welding speed is 0.5-0.6 m/min, and the welding of the weld is completed in the 4-layer bead. In composite welding, the groove angle is 30°, the laser power is 2000W, the arc voltage is 19-22V, the welding current is 165-190A, the welding speed is 0.5-0.6m/min, and the two-layer weldway completes the welding of the weld.
(2) High-power solid-state laser (Nd:YAG) + pulsed MIG arc hybrid heat source welding technology for aluminum alloy materials. 5A06 (LF6) aluminum alloy was used as the research object, and the welding parameters of aluminum alloy laser + arc hybrid welding were studied. The influence law of the penetration depth. Studies have shown that under the same welding heat input, the weld penetration obtained by the composite welding is greater than that of the same current pulsed MIG welding; under the same weld penetration, the composite welding is higher than the pulsed MIG welding of the same current. Welding speed, lower heat input and less distortion. Figure 12 is a comparison of welding speed and welding heat input for hybrid welding and single pulse MIG welding under the same weld penetration.
The test also compares the weld formation of single pulse MIG welding and laser + pulse MIG welding. The research shows that when the power of the MIG arc heat source is small, because the aluminum alloy welding heat conduction is fast, the welding wire is difficult to wet with the base material after melting. It is only deposited on the surface of the weld. After compounding a certain energy laser on the basis of the arc, the residual height and the melt ratio of the weld are reduced, and the molten metal can be well wetted with the base material. When the power of the MIG arc heat source is large and the welding speed is fast, due to the fast cooling speed of the weld, the surface tension of the molten pool metal is large, resulting in a discontinuous hump weld. If a laser power source of a certain power is combined on this basis, the cooling rate of the weld bead can be reduced, and the surface tension of the molten pool metal can be reduced, thereby obtaining continuous weld bead formation. Figure 13 shows the appearance of the weld bead during high-speed welding of 5A06 aluminum alloy.
(3) Aluminum/steel large spot Nd:YAG laser + pulse MIG composite heat source high-efficiency melting - Brazing technology based on laser + arc composite heat source welding process, the laser energy is precisely adjustable and the laser has stable arc and improves the stability of the welding process In order to improve the welding speed, a large-spot laser-arc composite heat source for welding dissimilar metals is proposed. High-quality high-efficiency fusion-bending connection of 5A02 aluminum alloy sheet and cold-rolled hot-dip galvanized steel sheet and cold-rolled hot-dip aluminized steel sheet with large spot Nd:YAG laser + pulsed MIG composite heat source welding (aluminum base metal for fusion welding, weld seam) It is brazed to the steel base metal. The maximum welding speed can reach 5.0m/min. The fracture position of the tensile specimen occurs in the heat affected zone of the aluminum base metal. The maximum tensile strength of the joint can reach 5A02. The tensile strength is about 75%, which is close to the strength of the ordinary fusion welded joint of 5A02 aluminum alloy. X-ray diffraction analysis showed that Fe 3 Al , FeAl 2 , Fe 2 Al 5 and FeAl 3 intermetallic compounds were formed at the interface of the brazing joint of aluminum/steel fusion-weld joint. The thickness of the compound layer was in the range of 1.5 to 4 μm. The presence of the Al-Fe intermetallic compound layer has little effect on the strength of the joint; the energy spectrum analysis shows that the Al and Fe atoms at the interface of the joint brazing joint are sufficiently diffused.
Figure 14 shows the weld of 5A02 aluminum alloy sheet and cold-rolled hot-dip galvanized steel sheet welded by large spot Nd:YAG laser + pulse MIG composite heat source high-efficiency fusion-brazing technology.
2. Application of laser + arc hybrid heat source welding technology
Harbin Welding Research Institute has successfully applied the research and development of laser + arc hybrid heat source welding technology to the production of actual products. Typical products are stainless steel large display housing (thickness 1.5mm, size 900mm × 650mm × 160mm) welding, The welding deformation problem of large thin-walled members is effectively solved; the welding of high-strength steel and ultra-high-strength steel shock absorber steel body and cylinder (strength 1000～1780MPa, thickness 12～25mm) effectively solves welding cracks and cylinders Burning of the inner chrome plating layer and deformation of the member. Figure 15 shows the welding of the shock absorber cylinder using laser + arc hybrid heat source welding technology. Harbin Welding Research Institute has successfully solved the stainless steel double-sided composite board by laser + arc composite heat source welding technology (the thickness of the stainless steel composite layer is about 0.15mm, the material is 0Cr18Ni9Ti, the base layer is made of Q235 low carbon steel material, and the thickness is 1.0~2.0 Between mm) Corrosion and deformation of welded joints. In addition, Harbin Welding Research Institute has applied laser + arc hybrid heat source welding technology to the repair of large aluminum alloy molds, and successfully solved the welding deformation problem of large aluminum alloy mold repair.
Fourth, the conclusion
Harbin Welding Research Institute has done a lot of work in laser and laser + arc hybrid heat source welding technology research, and applied the research results to the actual product manufacturing, solving the welding technology problems of various products. At present, the laser welding process is relatively mature, and for the new welding technology of laser + arc hybrid heat source welding, the research work mainly focuses on the process characteristics of this welding method, and the interaction between laser and arc in the laser + arc composite heat source welding. Problems such as mechanism and characteristics of welding heat sources need to be further studied theoretically.
Previous page
Multichannel Peristaltic Pumps
As Multichannel Peristaltic Pumps, a variety of tubes can be installed to meet the needs of different flow rates,
Multiple pump heads can be connected in series to achieve multichannel peristaltic pumps. the super high performance is destined to become one of the most popular models.
Multichannel Peristaltic Pumps deliver liquid only through the hose and do not pollute the pump body. Changing the hose can transport different liquids. Your ideal choice for liquid handling.
Multichannel Peristaltic Pumps,Small Bottle Filling Peristaltic Pump,4 Channels Peristaltic Pump,Chemical Liquid Filling Pump
Baoding Chuangrui Precision Pump Co., Ltd. , https://www.chuangruipump.com