RU2265674C1 - Composition of welding wire - Google Patents

Abstract

FIELD: metallurgy; welding materials; welding alloys of Al-Mg, Al-Mg-Li and Al-Zn-Mg-Cu systems.

SUBSTANCE: proposed welding wire contains magnesium, zirconium, scandium, beryllium, boron, manganese, aluminum, neodymium and at least two elements from group containing terbium, tin and vanadium. Proposed wire possesses high resistance to exploitation corrosion and hot cracks in welded joints of Al-Mg, Al-Mg-Li and Al-Zn-Mg-Cu system.

EFFECT: enhanced corrosion resistance of welding wire.

2 tbl, 6 ex

Description

The invention relates to welding technology, in particular to welding materials, and can be used for the manufacture of filler wire for welding aluminum alloys of AI-Mg, AI-Mg-Li, Al-Zn-Mg-Cu systems.

Known wrought alloy based on aluminum, having a chemical composition, wt.%:

Magnesium 3.9-4.9 Titanium 0.01-0.1 Beryllium 0.0001-0.005 Zirconium 0.05-0.15 Scandium 0.2-0.5 Cerium 0.001-0.004 Aluminum Rest

RF patent No. 2085607

However, the known alloy used as filler material in fusion welding of an alloy of the Al-Zn-Mg-Cu system (1913) does not provide the corrosion resistance of the welded joints, especially when testing for delaminating corrosion (RSK). DSC on the seam, the heat affected zone of the welded joint is 6-7 points.

Known weldable corrosion-resistant aluminum alloy containing, wt.%:

Magnesium 3.0-5.0 Zirconium 0.05-0.15 Manganese 0.05-0.12 Titanium 0.01-0.2 Scandium 0.15

and / or

Terbium 0.005-0.15

and / or one element of

lanthanides

Silicon ≤0.2 Aluminum Rest

U.S. Patent 6,258,318

The use of wire from this alloy as a filler material in fusion welding of alloy 1913 does not provide sufficient resistance to the formation of hot cracks and CSC. Critical speed of deformation of a welded joint according to a sample of MVTU im. N.E.Bauman is less than 1 mm / min, RSK> 6 points.

The closest analogue adopted for the prototype is an alloy based on aluminum, which can be used as a filler wire of the following chemical composition, wt.%:

Magnesium 5.5-6.5 Zirconium 0.02-0.15 Scandium 0.2-0.3 Beryllium 0.0001-0.005 Boron 0.001-0.01 Manganese 0.5 -0.7 Lanthanum 0.1-0.2 Aluminum Rest

RF patent No. 2148101

Moreover, ∑Sc + La = 0.3-0.4

The disadvantage of the prototype alloy is that its use as a filler wire for welding alloys of Al-Mg, Al-Mg-Li, Al-Zn-Mg-Cu systems, in particular alloy 1913 of the Al-Zn-Mg-Cu system, is not makes it possible to increase the corrosion resistance of the welded joint. DSC in the heat affected zone> 6 points.

An object of the invention is to develop the composition of the filler wire, providing increased resistance to delaminating corrosion and to the formation of hot cracks in welded joints of aluminum alloys of the Al-Zn-Mg-Cu, Al-Mg, Al-Mg-Li systems.

To achieve the technical task, a filler wire composition is proposed comprising: magnesium, zirconium, scandium, boron, beryllium, manganese, aluminum, in which neodymium and at least two components from the group of terbium, tin, vanadium are added, in the following ratio components, wt.%:

Magnesium 5.5-6.5 Zirconium 0.002-0.15 Scandium 0.1-0.3 Beryllium 0.0001-0.005 Boron 0.001-0.01 Manganese 0.2-0.4 Neodymium 0.1-0.2

At least two components from the group:

Terbium 0.005-0.15 Tin 0.01-0.05 Vanadium 0.05-0.15 Aluminum rest

With the declared content and ratio of components in the filler material, secondary precipitates of dispersed particles of intermetallic compounds containing aluminum, scandium, neodymium, terbium, and vanadium are formed. Intermetallic compounds of these metals, acting as centers of decomposition of a solid solution, change the location of zinc phase precipitates (MgZn ₂ Al _n Mg _m Zn _p ) along grain boundaries and thereby reduce the tendency to delaminating corrosion along the weld and fusion zone of the welded joint. In addition, complex alloying with scandium, neodymium, and at least two components from the group consisting of terbium, tin, and vanadium with the stated ratio of components reduces the temperature range of brittleness of the weld metal and reduces the tendency to form hot cracks during fusion welding of aluminum alloys of Al systems Mg, Al-Mg-Li, Al-Zn-Mg-Cu.

Examples of implementation

In laboratory conditions, alloys were smelted, the composition of which is given in Table 1. The ingots, after homogenization and machining, were hot pressed to bars with a diameter of 6 mm. Then a drawing was carried out with intermediate annealing to obtain a wire with a diameter of 2 mm. Resistance to CSC and the formation of hot cracks was evaluated. The last indicator was determined by the method of MVTU im. N.E.Bauman at the installation LPT1-6 with forced transverse tensile deformation of the samples during welding, which was carried out with a filler wire of the proposed composition according to the mode: I _st = 130A, Argon-arc welding for corrosion tests was carried out automatically (automatic machine ADSV-7) with the studied filler materials according to mode I _st = 145A, V _st = 18 m / h.

As can be seen from table 2, the use of the claimed composition of the filler wire allows you to double the resistance to delaminating corrosion and crack resistance of the welded joint of alloy 1913 of the Al-Zn-Mg-Cu system by about 30%. The same properties were obtained in the welded joint of Al-Mg-Li alloy.

The use of the proposed filler wire will allow the use of high-strength and lithium-containing aluminum alloys in the welded structures of aerospace technology, to increase their operational reliability and durability. Reduce the weight of the product by about 15% (due to the replacement of riveted joints with welded ones).

Table 1 Filler wire No. of composition p / p Chemical composition, wt.% Mg Zr Sc Be IN Mn Nd Tb Sn V Al Proposed 1 5.5 0.002 0.1 0.0001 0.001 0.2 0.1 0.005 0.01 0.05 Rest 2 6.5 0.15 0.3 0.005 0.01 0.4 0.2 0.15 0.05 0.15 - 3 6.0 0.08 0.2 0.0025 0.005 0.35 0.15 0.08 0,025 0.08 - 4 6.0 0.08 0.2 0.0025 0.005 0.35 0.15 0.08 0,025 - - 5 6.0 0.08 0.2 0.0025 0.005 0.35 0.15 0.08 - 0.08 - 6 6.0 0.08 0.2 0.0025 0.005 0.35 0.15 - 0,025 0.08 - Prototype 7 6.0 0.08 0.25 0.0025 0.005 0.6 La 0,1 - - - -

table 2 Filler wire No. of composition p / p Critical strain rate, V _cr , mm / min. Delaminating corrosion, score. Weld fusion zone Weld Proposed 1 4.0 3 4 2 3.6 4 3 3 4.0 4 3 4 3.85 4 3 5 4.1 3 3 6 3.85 3 3 Prototype 7 2.75 7 6

Claims (1)

The composition of the filler wire containing magnesium, zirconium, scandium, beryllium, boron, manganese, aluminum, characterized in that it additionally contains neodymium and at least two elements from the group consisting of terbium, tin, vanadium, in the following ratio of components, wt. %: Magnesium 5.5-6.5 Zirconium 0.002-0.15 Scandium 0.1-0.3 Beryllium 0.0001-0.005 Boron 0.001-0.01 Manganese 0.2-0.4 Neodymium 0.1-0.2 at least two components from the group Terbium 0.005-0.15 Tin 0.01-0.05 Vanadium 0.05-0.15 Aluminum Rest