CN103317258A - Active agent for aluminum alloy active TIG welding and using method - Google Patents

Abstract

The invention provides an active agent for aluminum alloy active TIG welding and a using method. The active agent is composed of MnCl2, V2O5, SiO2 and Al2O3. The active agent comprises, by weight, 50-85% of MnCl2, 10-20% of V2O5, 0-10% of SiO2 and 5-20% of Al2O3. The using method comprises the following steps that (1) before welding, water adsorbed by the active agent and crystal water of the active agent are removed completely; (2) the active agent is ground and screened; (3) a workpiece to be welded is wiped through acetone, and oil contamination on the surface of the workpiece is removed; (4) surface fusion welding is carried out on the workpiece in the welding method of non-wire filling automatic alternating-current CTFA-TIG welding, powder of the active agent is conveyed while welding is started, and powder feeding is stopped after arc extinguishing.

Description

The activating agent and the using method that are used for the active TIG weldering of aluminium alloy

Technical field

The present invention relates to active welding method.

Background technology

That aluminium alloy has is in light weight, intensity is high and advantage such as corrosion resistance and good, in the application in fields such as Aero-Space, pressure vessels for the chemical industry, shipping vehicle and power electronics more and more widely, becomes one of the most frequently used nonferrous materials at present.Research at its welding method of carrying out and technology is subject to people's attention day by day.Because thermal conductivity factor and the specific heat capacity of aluminium alloy are all very big, welding deformation is big, usually the welding method that adopts has: argon tungsten-arc welding (TIG weldering), plasma welding and electron beam welding etc., wherein common with the AC-TIG WELDING weldering, yet TIG weldering single-pass welding fusion penetration is more shallow, causes welding production efficiency and reduces.

In the last few years, active TIG welding had caused worldwide extensive concern, and it significantly increases fusion penetration by introduce active element in welding process.At present, the introducing mode of active element mainly is divided into two kinds, and a kind of is by active gases, and another kind is by at mother metal surface-coated activating agent.The former introduces O isoreactivity element by active gases, the surface tension temperature coefficient that makes molten pool metal by negative value become on the occasion of, the molten pool metal ecto-entad flows, thereby the heat that makes the electric arc input reaches the purpose of remarkable increase fusion penetration more effectively to the transmission of bottom, molten bath.Yet this mode can not be introduced alloying element in welding process, be difficult to improve its tissue and performance by the composition of regulating weld metal, and for aluminum alloy materials, because its surface tension is lower, thermal conductivity is higher, make material surface tension force temperature coefficient and thermograde all lower, a little less than the effect that changes Marangoni convection current increase fusion penetration, it is the dominant mechanism that fusion penetration increases that electric arc shrinks.The latter applies the very thin surfactant of one deck at the good surface of the work of polishing before welding, and can make electric arc contraction or Marangoni convection current to change, and weld penetration significantly increases.This active element is introduced mode can regulate tissue and the composition of weld seam by changing bioactive agent composition, improves weld properties.But this mode need increase by one activating agent applies operation, and if the coated technique complexity, then more cannot say for sure to demonstrate,prove to be not easy to coating quality in actual production, use.

Summary of the invention

The objective of the invention is to increase weld penetration, guarantee that appearance of weld is good, the refinement weld grain improves Weld Performance, reduces weld defect.

The present invention is that its activating agent is by MnCl for activating agent and the using method of the active TIG weldering of aluminium alloy ₂, V ₂O ₅, SiO ₂, and Al ₂O ₃Form, by weight percentage, its component is: MnCl ₂50-85%, V ₂O ₅10-20%, SiO ₂0-10%, Al ₂O ₃5-20%.

Be used for the using method of the activating agent of the active TIG weldering of aluminium alloy, the steps include:

(1) needs before the weldering the activating agent heating, the moisture of activating agent absorption and the crystallization water of itself are sloughed fully;

(2) grind and sieve, activating agent powder particle size is between 100 orders-400 order;

(3) with workpiece to be welded acetone wiping, remove surface and oil contaminant, clean 3 min-7 min with 5%-10%NaOH solution then, with the clear water flushing of flowing, use 30%HNO again ₃In the solution and 1 min-3 min, rinse well with mobile clear water equally, at last with the alcohol swab wiping and dry up sample;

(4) welding method adopts the automatic AC GTFA-TIG weldering that do not fill silk that workpiece is carried out surperficial melting welding, and the delivery of active agents powder stops powder feeding in the time of the welding beginning after the blow-out.

Gas is carried active TIG weldering, i.e. GTFA-TIG weldering (Gas Transfer Flux Activating TIG Welding) is a kind of active TIG welding method that Lanzhou University of Science ﹠ Technology proposes.This method has changed the introducing mode of traditional active element, makes the activating agent powder introduce welding process by welding protection gas by an automatic powder feeding device and implements welding.

Usefulness of the present invention is:Activating agent can increase the electromagnetic force in electric arc and the molten bath by shrinking electric arc, makes arc heat more effectively to the transmission of bottom, molten bath, thereby significantly increases fusion penetration.Utilize active agent formulation of the present invention to carry out aluminium alloy gas and carry active TIG weldering, remarkable shrink welded electric arc, the weld penetration that is multiplied, and guarantee that appearance of weld is good, and making the weld grain refinement, weldquality improves, and welds production efficiency and significantly improves.

Description of drawings

Fig. 1 is GTFA-TIG welding system schematic diagram; Fig. 2 is for general T IG weldering and adopt face of weld pattern of the present invention, and Fig. 3 and Fig. 4 are respectively its seam cross-section pattern; Fig. 5 is the welding arc pattern of general T IG weldering under the same weld standard, and Fig. 6 is welding arc pattern of the present invention, and Fig. 7 is general T IG weldering and weldingvoltage of the present invention contrast under the same weld standard; Fig. 8 is the weld seam central area metallographic structure of general T IG weldering, and Fig. 9 is weld seam of the present invention central area metallographic structure.

The specific embodiment

The present invention is that its activating agent is by MnCl for activating agent and the using method of the active TIG weldering of aluminium alloy ₂, V ₂O ₅, SiO ₂, and Al ₂O ₃Form, by weight percentage, its component is: MnCl ₂50-85%, V ₂O ₅10-20%, SiO ₂0-10%, Al ₂O ₃5-20%.

Be used for the using method of the activating agent of the active TIG weldering of aluminium alloy, the steps include:

(1) needs before the weldering the activating agent heating, the moisture of activating agent absorption and the crystallization water of itself are sloughed fully;

(2) grind and sieve, activating agent powder particle size is between 100 orders-400 order;

(3) with workpiece to be welded acetone wiping, remove surface and oil contaminant, clean 3 min-7 min with 5%-10%NaOH solution then, with the clear water flushing of flowing, use 30%HNO again ₃In the solution and 1 min-3 min, rinse well with mobile clear water equally, at last with the alcohol swab wiping and dry up sample;

(4) welding method adopts the automatic AC GTFA-TIG weldering that do not fill silk that workpiece is carried out surperficial melting welding, and the delivery of active agents powder stops powder feeding in the time of the welding beginning after the blow-out.

Be example with the thick 3A21 aluminium alloy plate of 8 mm.Need before the weldering the activating agent heating, the moisture of activating agent absorption and the crystallization water of itself are sloughed fully, grind and screening, activating agent powder particle size is between 100 orders-400 order.With sample acetone wiping, remove surface and oil contaminant, clean 3 min-7 min with 5%-10%NaOH solution then, with the clear water flushing of flowing, use 30%HNO again ₃In the solution and 1 min-3 min, rinse well with mobile clear water equally, at last with the alcohol swab wiping and dry up sample.Welding method adopts the automatic AC GTFA-TIG weldering that do not fill silk that workpiece is carried out surperficial melting welding, and the delivery of active agents powder stops powder feeding in the time of the welding beginning after the blow-out.

Embodiment 1:

The aluminium alloy sample dimensions that this test is selected for use is 150 mm * 80 mm * 8 mm, adopt as shown in Table 1 and Table 2 and carried out the surperficial melting welding that general T IG welds and GTFA-TIG welds respectively under the welding conditions, GTFA-TIG welds the weight proportion of its each component in the employed active agent formulation: MnCl ₂67.5%, V ₂O ₅15.0%, SiO ₂2.5%, Al ₂O ₃15.0%.General T IG weldering and appearance of weld of the present invention as shown in Figure 2, the appearance of weld that GTFA-TIG welds is good.The seam cross-section of general T IG weldering and GTFA-TIG weldering respectively as shown in Figure 3 and Figure 4.The weld penetration of general T IG weldering and molten wide 1.95mm and the 9.39mm of being respectively, the weld penetration of GTFA-TIG weldering and molten wide 6.22mm and the 8.28mm of being respectively, adopt the weld penetration of the GTFA-TIG weldering of above-mentioned active agent formulation to reach 3.2 times that general T IG welds, melt wide 0.88 times for general T IG weldering, guaranteed that simultaneously appearance of weld is good.

The table 1 general T IG welder standard of planting

Table 2 exchanges GTFA-TIG welder's standard of planting

The electric arc pattern of the GTFA-TIG weldering of general T IG weldering and employing activating agent and weldingvoltage are respectively as Fig. 5, Fig. 6 and shown in Figure 7, because the introducing of activating agent is compared with general T IG weldering, GTFA-TIG weldering electric arc obviously shrinks, and weldingvoltage has increased about 4V.

Embodiment 2:

Technological specification welds shown in employing table 3 and the table 4 respectively, metallographic structure such as Fig. 8 and shown in Figure 9 of the weld seam central area of the GTFA-TIG weldering of general T IG weldering and employing embodiment one described active agent formulation.Compare with general T IG weldering, adopt the obvious refinement of weld grain of the GTFA-TIG weldering of embodiment one described active agent formulation, organize finer and close.

GTFA-TIG weld seam to two groups of employing embodiment one described active agent formulations carries out the cross directional stretch performance test, and the test specimen fracture position all is positioned at weld heat-affected zone, and the maximum tensile strength is 108.6Mpa, has reached 93.6% of mother metal.

The table 3 general T IG welder standard of planting

The table 4 GTFA-TIG welder standard of planting

Embodiment 3:

Under the welding conditions of table 4, adopt the GTFA-TIG welding line of embodiment one described active agent formulations to carry out x-ray inspection to two groups, the flaw detection parameter is: tube voltage 150 KV, tube current 5 mA, time for exposure 4 min.Weld seam comments the sheet result to be the I level, adopts the GTFA-TIG weld seam of embodiment one described active agent formulation not find pore, slag inclusion, crackle and bar defect.

Claims (2)

1. the activating agent that is used for the active TIG weldering of aluminium alloy is by MnCl ₂, V ₂O ₅, SiO ₂, and Al ₂O ₃Form, by weight percentage, its component is: MnCl ₂50-85%, V ₂O ₅10-20%, SiO ₂0-10%, Al ₂O ₃5-20%.

2. be used for the using method of the activating agent of the active TIG weldering of aluminium alloy, the steps include:

(1) needs before the weldering the activating agent heating, the moisture of activating agent absorption and the crystallization water of itself are sloughed fully;

(2) grind and sieve, activating agent powder particle size is between 100 orders-400 order;

(3) with workpiece to be welded acetone wiping, remove surface and oil contaminant, clean 3 min-7 min with 5%-10%NaOH solution then, with the clear water flushing of flowing, use 30%HNO again ₃In the solution and 1 min-3 min, rinse well with mobile clear water equally, at last with the alcohol swab wiping and dry up sample;

(4) welding method adopts the automatic AC GTFA-TIG weldering that do not fill silk that workpiece is carried out surperficial melting welding, and the delivery of active agents powder stops powder feeding in the time of the welding beginning after the blow-out.

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