CN103317258B

CN103317258B - Active agent for aluminum alloy active TIG welding

Info

Publication number: CN103317258B
Application number: CN201310291779.2A
Authority: CN
Inventors: 黄勇; 李涛; 姚宇航
Original assignee: Lanzhou University of Technology
Current assignee: Lanzhou University of Technology
Priority date: 2013-07-12
Filing date: 2013-07-12
Publication date: 2015-07-08
Anticipated expiration: 2033-07-12
Also published as: CN103317258A

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

For the activating agent of aluminium alloy Active tungstic acid

Technical field

The present invention relates to active welding method.

Background technology

Aluminium alloy have lightweight, intensity is high and the advantage such as corrosion resistance and good, the application at present in fields such as Aero-Space, pressure vessels for the chemical industry, shipping vehicle and power electronics is more and more extensive, becomes one of the most frequently used nonferrous materials.The welding method of carrying out for it and the research of technique, be subject to people's attention day by day.Due to the thermal conductivity factor of aluminium alloy and specific heat capacity all very large, welding deformation is large, the welding method of usual employing has: argon tungsten-arc welding (TIG weldering), plasma weldering and electron beam welding etc., wherein common with AC-TIG WELDING weldering, but TIG weldering single-pass welding fusion penetration is more shallow, causes welding production efficiency to reduce.

In the last few years, Active tungstic acid connection caused worldwide extensive concern, and it makes fusion penetration significantly increase by introducing active element in welding process.At present, the incorporation way of active element is mainly divided into two kinds, and one is by active gases, and another kind is by applying activating agent on mother metal surface.The former introduces O isoreactivity element by active gases, make the surface tension temperature coefficient of molten pool metal by negative value become on the occasion of, molten pool metal ecto-entad flows, thus the heat that electric arc is inputted is more effectively to molten bath lower transport, reaches the object significantly increasing fusion penetration.But this mode can not introduce alloying element in welding process, be difficult to by regulating the composition of weld metal to improve its structure and properties, and for aluminum alloy materials, because its surface tension is lower, thermal conductivity is higher, make material surface tension temperature coefficient and thermograde all lower, more weak by the effect changing Marangoni convection current increase fusion penetration, arc constriction is the dominant mechanism that fusion penetration increases.The latter applies the very thin surfactant of one deck at the surface of the work of having polished before weldering, and arc constriction or Marangoni convection current can be made to change, and weld penetration significantly increases.This active element incorporation way by changing bioactive agent composition, can regulate the microstructure and composition of weld seam, improving weld properties.But this mode needs increase by one activating agent coating operation, and if coated technique is complicated, is then more difficult to ensure card coating quality, is not easy to apply in actual production.

Summary of the invention

The object of the invention is to increase weld penetration, ensure that appearance of weld is good, refinement weld grain, improve Weld Performance, reduce weld defect.

The present invention is the activating agent for aluminium alloy Active tungstic acid, and its activating agent is by MnCl ₂, V ₂o ₅, SiO ₂, and Al ₂o ₃composition, by weight percentage, its component is: MnCl ₂50-85%, V ₂o ₅10-20%, SiO ₂0-10%, Al ₂o ₃5-20%.

For the using method of the activating agent of aluminium alloy Active tungstic acid, the steps include:

(1) need before weldering activating agent heating, the moisture that activating agent is adsorbed and the crystallization water of itself are sloughed completely;

(2) grind and sieve, Agent Powder granular size is between 100 order-400 orders;

(3) by workpiece acetone to be welded wiping, removing surface and oil contaminant, then cleans 3 min-7 min with 5%-10%NaOH solution, rinses, then use 30%HNO with flowing clear water ₃in solution and 1 min-3 min, to rinse well with flowing clear water equally, finally dry up surface of the work with alcohol swab wiping;

(4) welding method adopts the automatic AC GTFA-TIG that do not fill silk to weld, and delivery of active agents powder while welding starts, stops powder feeding after blow-out.

Gas conveying Active tungstic acid, i.e. GTFA-TIG weldering (Gas Transfer Flux Activating TIG Welding) is that a kind of Active tungstic acid that Lanzhou University of Science & Technology proposes connects method.The method changes the incorporation way of traditional activated element, makes Agent Powder introduce welding process by welding protection gas implement welding by an automatic powder feeding device.

usefulness of the present invention is:activating agent by shrinking electric arc, can make the electromagnetic force in electric arc and molten bath increase, making arc heat more effectively to molten bath lower transport, thus significantly increase fusion penetration.Active agent formulation of the present invention is utilized to carry out aluminium alloy gas conveying Active tungstic acid, can remarkable shrink welded electric arc, be multiplied weld penetration, and ensure that appearance of weld is good, makes weld grain refinement, and weldquality raising, welding production efficiency significantly improves.

Accompanying drawing explanation

Fig. 1 is GTFA-TIG welding system schematic diagram; Fig. 2 is general T IG weldering and adopts face of weld pattern of the present invention, Fig. 3 and Fig. 4 is respectively its seam cross-section pattern; Fig. 5 is the welding arc pattern of general T IG weldering under same weld specification, 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 same weld specification; Fig. 8 is the Weld pipe mill region metallographic structure of general T IG weldering, and Fig. 9 is Weld pipe mill region metallographic structure of the present invention.

Detailed description of the invention

For the 3A21 aluminium alloy plate that 8 mm are thick.Need activating agent heating before weldering, the moisture that activating agent is adsorbed and the crystallization water of itself are sloughed completely, and grind and sieve, Agent Powder granular size is between 100 order-400 orders.Sample is used acetone wiping, removing surface and oil contaminant, then cleans 3 min-7 min with 5%-10%NaOH solution, rinses, then use 30%HNO with flowing clear water ₃in solution and 1 min-3 min, to rinse well with flowing clear water equally, finally dry up sample with alcohol swab wiping.Welding method adopts the automatic AC GTFA-TIG weldering that do not fill silk to carry out surperficial melting welding to workpiece, and delivery of active agents powder while welding starts, stops powder feeding after blow-out.

Embodiment 1:

The aluminium alloy sample dimensions that this test is selected is 150 mm × 8, mm × 80 mm, carried out the surperficial melting welding that general T IG weldering and GTFA-TIG weld under adopting welding conditions as shown in Table 1 and Table 2 respectively, GTFA-TIG welds the weight proportion of its each component in the active agent formulation used: MnCl ₂67.5%, V ₂o ₅15.0%, SiO ₂2.5%, Al ₂o ₃15.0%.As shown in Figure 2, the appearance of weld of GTFA-TIG weldering is good for general T IG weldering and appearance of weld of the present invention.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 is respectively 1.95mm and 9.39mm with molten wide, the weld penetration of GTFA-TIG weldering is respectively 6.22mm and 8.28mm with molten wide, the weld penetration adopting the GTFA-TIG of above-mentioned active agent formulation to weld reaches 3.2 times of general T IG weldering, melt wide 0.88 times for general T IG weldering, ensure that appearance of weld is good simultaneously.

Table 1 general T IG Welding specification

Table 2 exchanges GTFA-TIG Welding specification

The electric arc pattern of the GTFA-TIG weldering of general T IG weldering and employing activating agent and weldingvoltage are respectively as shown in Fig. 5, Fig. 6 and Fig. 7, and due to the introducing of activating agent, compared with welding with general T IG, GTFA-TIG welds electric arc and obviously shrinks, and weldingvoltage adds about 4V.

Embodiment 2:

Shown in employing table 3 and table 4, technological specification welds respectively, and general T IG welds and adopt the metallographic structure in the Weld pipe mill region that the GTFA-TIG of active agent formulation described in embodiment one welds as shown in Figure 8 and Figure 9.Compared with welding with general T IG, adopt the obvious refinement of weld grain of the GTFA-TIG weldering of active agent formulation described in embodiment one, organize finer and close.

Adopt the GTFA-TIG weld seam of active agent formulation described in embodiment one to carry out transverse tensile property test to two groups, test specimen fracture position is all positioned at weld heat-affected zone, and the maximum tensile strength is 108.6Mpa, reaches 93.6% of mother metal.

Table 3 general T IG Welding specification

Table 4 GTFA-TIG Welding specification

Embodiment 3:

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

Claims

1. for the activating agent of aluminium alloy Active tungstic acid, by MnCl ₂, V ₂o ₅, SiO ₂and Al ₂o ₃composition, by weight percentage, its component is: MnCl ₂50-85%, V ₂o ₅10-20%, SiO ₂0-10%, Al ₂o ₃5-20%;

The step of use activating agent is:

(3) by workpiece acetone to be welded wiping, removing surface and oil contaminant, then cleans 3 min-7 min with 5%-10%NaOH solution, rinses, then use 30%HNO with flowing clear water ₃in solution and 1 min-3 min, to rinse well with flowing clear water equally, finally dry up surface of the work by alcohol wipe;