DE1927432B2 - Electrode for build-up welding on steel products - Google Patents

Description

4. Electrode according to claim 1 to 3, characterized in that the purpose of the present invention consists in characterized in that the components mentioned eliminate the disadvantages mentioned.

the electrode in the following percentage ratio to The invention was based on the object

Total weight of the electrode includes: an electrode with a core of such an

ru ι KH ir- r-Λ ιλ κ- / η composition that has a high

Chromium carbide (Cr ₃ C ₂₎ 40 to 60 _sc hleißfesiigkeit of the welded material with

Aluminum powder up to 3 _ß f ^ _{housing on} ^b _carbides guaranteed.

Natnums.l.konuond. . to 3 f _f ^ _{is solved by the fact that [n}

Chromium boride or boron carbide .. Ibis 8 _{der E} £ _{ktrode ZUI ^ Build-up} welding on steel

Nickel jacket remainder of the products consisting of a nickel jacket and the

5. Electrode according to claim 1 to 3, characterized in that there is a core containing chromium carbide, in particular that the components mentioned _{contain chromium carbide (Cr 3} C ₂ ), in addition to the above-mentioned electrode in the following ratio to the Ge component according to the invention in aluminum powder total weight of the electrode included: an amount of 1 to 3 percent by weight is included.

To remove pores in the welded

Chromium carbide (Cr ₃ C ₂ ) 40 to 60 35 layer, the core also contains sodium silicon

Aluminum powder Ibis 3 fluoride (Na ₂ SiF ₆ ) in an amount of 1 to 3 weight-

Sodium fluoride 1 to 3 percent.

B— Cr — Fe — Al alloy For strengthening the binder, the core contains

(15 to 25% B, 30 to 50% Cr, additionally chromium boride or boron carbide or alloy

2 to 8% Al, otherwise Fe) 2 to 12 40 ments of boron with chromium.

Nickel jacket remainder A particularly cheap solution can be when using an electrode are brought about, whose

contain said components in the following percentage ratio to the total weight of the electrode 45 are:

The present invention relates to factory chromium carbide (Cr ₁ C ₂ ) 40 to 60

Itoffe for welding and surfacing, ins- aluminum powder 1 to 3

special on electrodes for surfacing sodium silicofluoride ". '.'. '.'. '.'. '.'." .. Ibis 3

“On steel products. Chromium boride or boron carbide .... 1 to 8

The present invention is particularly successful
richly applied to build-up welding on parts,

which are operated under the conditions of wear and tear, the manufacturing technology of which is used to reduce the cost of the electrode and to normalize and increase temperatures. components of the electrode mentioned in the following.From experience it is known that a particularly 55 percent ratio to the total weight of the electrode has high wear resistance alloys which, taken:
contain large amounts of solid carbides. To the

Build-up welding of such alloys uses chromium carbide (Cr ₃ C ₂ ) 40 to 60

tube electrodes made of a nickel or aluminum powder 1 to 3

Cobalt cladding and a core made of cast 60 sodium silicofluoride 1 to 3

tungsten carbides, more rarely carbides of other metals, B — Cr — Fe — Al alloy

e.g. from chromium. (15 to 25% B; 30 to 50% Cr;

For build-up welding of wear-resistant alloy 2 to 8% Al; Remainder Fe) 2 to 12

with a high content of carbides

bars made of sintered alloy are also used to a large extent

The present invention is carried out below, for example from an alloy Cr ₃ C _{2 - Ni}

Contains 85% Cr ₃ C ₂ and 15% Ni (see the journal, whose detailed description is explained in more detail.

»Welding technology«, No. 6, 1965 - in Russian). The jacket material and the carbide should be used

Melts have a minimum mutual solubility, which makes it possible to obtain the maximum content of carbides in the welded layer. Nickel was chosen as the sheath material and chromium carbide (Cr ₃ C ₂ ) as the carbide.

So that the jacket is rigid and strong enough, its weight should be at least 30 to 40% of the total weight of the electrode. The layer welded on with this electrode contains a raised one Amount of soft nickel binder and an insufficient amount of carbides. Such a welded one Layer wears unevenly; First of all, the soft alloy component wears out, whereby the carbides are exposed and crumbled out. The wear resistance of using this Electrode welded layer is low.

To overcome this disadvantage, the soft alloy component (the binder) must be solidified.

This is achieved in that aluminum is introduced into the core of the electrode next to the chromium carbide, as a result of which the intermetallide Ni ₃ Al is formed in the binder of the welded-on layer, which solidifies the binder. A more substantial strengthening of the binder, which is made by an alloy on a nickel base, is brought about by borides. For this reason, powder of chromium boride or powder is also introduced into the core of the electrode

ίο of boron carbide or powder of a B — Cr — Al — Fe alloy a. This alloy has the following composition: 15 to 25% B; 30 to 50% Cr; 2 ois S% AI; Remainder iron. This alloy is easy to grind, it is cheaper than chromium boride or the boron carbide.

In the following table 1, data are given for comparison, which the effect of the consolidation the binder of the welded metal.

Table 1

Build-up welding conditions

Hardness of the welded metal

medium hardness micro hardness (kp / mm ² )

(kp / mm ² ) _{of binder from} carbide,

2 3 4

Manual arc deposition welding with a rod made of a sintered alloy containing 85% Cr ₃ C ₂ and 15% Ni

Automatic submerged arc arc welding with an electrode that contains 59% Cr ₃ C ₂ , 1% Na ₂ SiF ₆ , 40% Ni

Automatic submerged arc deposition welding with an electrode containing 55% Cr ₃ C ₂ , 3% Al, 41% Ni,
Contains 1% Na _{2 SiF 6}

Automatic submerged arc deposition welding with an electrode containing 51% Cr ₃ C ₂ , 1.5% Al, 1% Na _{2 SiF 6} , 8% alloy of boron with chromium (composition see above)

48 to 60 180 to 220 2000 to 2200

42 to 45 200 to 250 2000 to 2200

42 to 45 320 to 400 2000 to 2200

55 to 58 552 to 662 2000 to 2200

From the information in Table 1 it can be seen that the introduction of aluminum and compounds containing boron in the core of the electrode makes it possible to increase the microhardness of the binder, in which solid chromium carbides are distributed.

By increasing the micro-hardness of the binder, it is a good idea to reduce the wear and tear of the melted To reduce metal.

The wear tests were carried out by venting the samples with a gas stream that was 10 percent by weight Contains particles of abrasive. Quartz sand or gas dust were used as abrasives of blast furnaces. The temperature of the sample was 400 "C, the gas pressure in front of the nozzle 2 atmospheres The angle of incidence of the abrasive on the surface to be worn (angle of incidence) 10, 30, 45 and 75 \ the test duration is 15 minutes.

The test results are shown in FIG. 1: Fig. La shows the test results with quartz sand, Fig. Ib these with furnace gas dust. Curve 1 shows the dependence of the wear of the welded-on layer, for example of the carbon steel (0.45% C), on the angle of incidence. Curve 2 shows the dependence of the wear on the welded layer, e.g. B. the high chromium tubular electrode (3.0-3.5% C, 25-30% Cr, 2-4% Ni, 2-4% Si, 0.8-1.51% Mn) from the angle of incidence. Curve 3 shows the dependence of the wear of the metal, which was welded on with a powder electrode containing a nickel jacket (40%) and chromium carbide (60%), on the angle of incidence. Curve 4 shows the dependence of the wear of the metal, which was welded on with the electrode with a rod made of sintered alloy (85% Cr ₃ C ₂ + 15% Ni), on the angle of incidence.

Curve 5 shows the dependency of the wear of the metal with the electrode according to the invention was welded on, from the angle of incidence.

It can be seen from the test results that the electrodes according to the invention ensure high wear resistance of the welded metal and are not inferior to _{rods made from a sintered alloy containing 85% Cr 3} C _2.

To remove pores in the welded-on layer, sodium silicofluoride _{(Na 2 SiF 6} ) is introduced into the core of the electrode in an amount of 1 to 3 percent by weight. The amounts of the other components of the electrode are chosen in such a way that maximum wear resistance and the lowest possible brittleness of the welded-on layer are achieved.

i is guaranteed. An increase in the amount of aoric components beyond the norm is characterized by an increase in the number and size of Accompanied by cracks. A decrease in the amount of boron-containing components leads to a decrease in the Wear resistance of the welded layer. For a better understanding of the invention are in the Table 2 shows specific examples.

Table 2

No of the composition
the electrode

Content of components, percent by weight
Chromium carbide chromium boride boron carbide

alloy
15 to 25% B,
30 to 50% Cr,
2 to 8% Al,
otherwise Fe aluminum
powder NajSiF, Nicki
manti 1.5 2.0 rest - 1.5 2.0 rest - 1.5 2.0 rest 2 1.5 2.0 rest 6th 1.5 2.0 rest

1
X. 59 2. 57 3. 57 4th 57 5. 53

The electrodes can be round in the form of wire, in the first case a nickel band, e.g. 0.3 χ 22 mm

Cross-section (of 5 - ^ - 6 mm in diameter) or in cross-section, in the second case two bands of

Form of tape with a cross section of 20 X 3 mm 15 0.3 χ 22 mm or 0.3 χ 24 mm cross section, are executed. For the coat one uses

1 sheet of drawings

Claims (3)

The tubular electrodes with the core made of tungsten "carbide" do not guarantee an even distribution of the carbides in the welded layer, 1. Electrode zu.n build-up welding on steel - because the tungsten carbides are a large specific product, which have a nickel jacket and a weight. In an effort to increase the structure of the core, the chromium carbides, in particular the welded-on layer of carbides, carbide Cr ₃ C contains, thereby giving the known electrodes a thin jacket, drawing the core In addition to the aforementioned, however, the rigidity of such a jacket is sufficient for component aluminum powder in an amount that the winding of the electrode on the coil and contains from 1 to 3 percent by weight. io their safe feeding into the focal zone of the light 2. Electrode after. Claim 1, characterized in the case of mechanized build-up welding processes is characterized by the fact that the kernel does not additionally contain sodium silicopotene. fluoride (Na-SiF ₆ ) in an amount of 1 to 3 Ge welding rods made of a sintered alloy are for contains weight percent. mechanized build-up welding, even if they are 3. Electrode according to claim 1 and 2, characterized in that 15 the maximum content of carbides in the indicated, that ensure the core in addition to the welded layer mentioned is not very suitable. It Components in addition chromium boride or boron is difficult, sometimes impossible, the cemented carbide or alloys of boron with chromium electrode in the form of wire to produce contains. Winding on bobbins is suitable.