SU1602642A1 - Method of surfacing wear-resistan alloys - Google Patents

Abstract

The invention relates to mechanical engineering and can be used in restoration and technological surfacing of machine parts, mainly working under conditions of direct interaction with hard abrasive media under shock loads, for example, in mining, ore-dressing, oil and gas exploration equipment, etc. and an increase in the strength of the deposited layer by reducing the residual stresses. The surfacing is performed by three electrodes, two of which — wire, low carbon with diameter D, are set symmetrically to the axis of the deposited layer at a distance M relative to each other, depending on the size of all electrodes, and create two independent weld pools. The third electrode, containing a mixture capable of self-propagating high-temperature synthesis, is set at a distance L from the line of the low-carbon electrodes in the direction opposite to the deposition direction, and the distance L is chosen depending on the size of the electrodes and the speed. As the third electrode, the wire electrode is oscillating with amplitude A. The tape electrode has a thickness B and a width C, and the wire electrode has a diameter E. When using a tape electrode, the distances M and E are given from the relations: M = (C + D + 1) ± 2 mm

L = 0.5 (D + B) + √D + KV + 2, mm, where V is the speed of the relative movement of the weld piece and electrodes, mm / s

K = 1.5 ... 2 s. When using a wire electrode, the distances M and L are set from the ratios M = (e + D – A + 1) ± 2, mm

L = 0.5 (e + D) + √D + KV + 2, mm. As a result of surfacing, a composite weld seam is formed, including synthesized carbide material located in a low-carbon matrix, with a transition zone between them. 2 hp f-ly, 3 ill.

Description

Fig: 1

the mixture capable of self-propagating high-temperature synthesis is set at a distance of 1 from the line of location of low-carbon electrodes in the direction opposite to the deposition direction, while the distance 1 is chosen depending on the size of the electrodes and the speed. The third electrode is taken accurate or oscillating with amplitude A wire electrode. The tape electrode has a thickness b and a width c, and the wire diameter is e. When using a tape electrode, the distance and and e are given from the relationships: iff (c + d + l) ± 2, mm; , 5 (d + b) + fd + KV + 2, mm, where V is the speed of the relative movement of the weld piece and electrodes, mm / s; , 5 .... 2c. When using a wire electrode, the distances m and 1 are determined from the relations m (e + d + A + l) ± 2 mm; , 5 (е + а) + - + КУ + 2, mm. As a result of surfacing, a composite surfacing) 1st weld is formed, including synthesized carbide material located in a low-carbon matrix, with a transition zone between them. 2 z.p, f-crystals, 3 silt, 1 tab.

The invention relates to mechanical engineering and can be used in the case of restoration and technological welding of machine parts.

The purpose of the invention is to increase the wear resistance of the deposited layer, as well as increase the strength of the deposited product by reducing the residual stresses.

The essence of the method is that the surfacing is carried out by three electrodes, two of which are wire, low carbon with diameter d, are set symmetrically to the axis of the deposited layer at a distance m relative to each other, depending on the size of all electrodes, and create two independent welding baths and the third electrode, containing a mixture capable of self-propagating high-temperature synthesis, is set at a distance of 1 from the line of location of low-carbon electrodes in the opposite direction to aplavki, the distance 1 is selected in dependence on the size of .mosti electrodes and deposition rate.

Alternatively, as the third electrode, a ribbon width c and a thickness b is taken, and the distance between low carbon electrodes is chosen within the following limits:

m () i2, mm,

and the distance 1 is set from the ratio ::

, 5 (d + b) + - id + KV + 2, mm, where V is the speed of the relative movement of the weld piece and electrodes, mm / s;

five

0

five

40

45

50

55

 . , 5 .... 2 s.

Also, as an option, a third wire with a diameter e is chosen, oscillations with amplitude A are reported to the electrode, and distances m and 1 are chosen from the ratios: m (e + d + A- -l) i: 2, mm,, 5 ( e - + - d) -i Id + KV- -2, mm.

Figure 1 shows the scheme for carrying out the method when using as an electrode containing a mixture capable of a self-propagating high-temperature synthesis (SHS), a tape electrode with a width and thickness of b; FIG. 2 is a diagram of the deposition process using an oscillating wire electrode with a mixture of diameter e; on fig.Z - cross-section of the deposited layer.

The method is carried out as follows.

Initially, the welding of low-carbon rollers 1 begins, then the powder tape or electric strip is started ;. genus 2 when moving parts 3 nd distance 1 (fig. 1,2). At the moment of welding, the powder mixture under the action of electric arcs burning between the flax-v and the part, as well as between the electrodes and the part, is initiated by SHS. During the synthesis, carbide compounds are sintered in the electrode, sintered in Kermet and sheathed with metal. Monolithicity And preheating in the process of material synthesis - powder tape eliminates splashing of hot metal, reduces its oxidation, and prevents dissolution of solid particles in the weld pool. . .

The course of the SHS process depends on the mutual arrangement of the two wire electrodes, installed symmetrically. relative to the deposition axis, and the third electrode containing a mixture capable of SHS.

The deviation of the distance 1 upward from the optimum leads to insufficient heating of the powder Q tape, which leads to incomplete synthesis of the powder mixture. With a decrease in 1, a burnout of the metal shell is observed under the influence of the total thermal energy that is absorbed during the synthesis (5th electrode and combustion of the electrode).

When surfacing both with powder tape and fluctuating powder

tape 8 and 10 mm wide and 2 mm thick and powder electrodes with a diameter of 5 mm. A powder mixture capable of self-propagating high-temperature synthesis was used to fill the powder tape and the electrode.

The method was carried out according to the described operations. In this case, the speed of moving the part (sample) was 6 mm / s. The amplitude of oscillations of the powders of the electrode is equal to 15 mm. The quality control of the deposited layer was carried out by measuring the hardness of TP-7P-1 using the Vickers method, estimating the percentage of pores and the uniformity of the deposited layer.

Data on surfacing 12 samples

the electrode supply of the powder electrode is carried out in the space between 20 is given in the table.

Small rollers welded with low-carbon samples. 1-3, were deposited by powder electrodes located at a distance m relative to each other. The distance ha, calculated from the 8 mm wide predvoy tape with different distances between the centers of low carbon electrodes t, calculated

-f-r-i (. III j / dv, Mi-l 1 ousasmim

lagaemo formula provides part-25 of the formula. Samples 4-6 were deposited

This (but not complete) movement of the layers deposited by different electrodes. As shown in FIG. 3, the layer, welded to part 3, consists of three varieties: I - low-carbon steel, weld-over with electrodes; II - carbide heterogeneous material; IV - a mixture of mild steel with a hard alloy. Layer I reduces the magnitude of the residual stresses, increases the adhesion of the carbide layer II to the substrate. Due to this, it is possible to increase the amount of carbide material, i.e. the fill factor of the powder tape or wire, leading to increased wear resistance.

As a result of surfacing, a composite

the same tape, but with a different distance between the center of the electrodes and the cross, the center of the powder tape 1.

Samples 7-9 were powdered 30 with a tape of 10 mm width at various

distance m and the same 1, coinciding with the optimum in the previous surfacing. Samples 10–12 were deposited with a powder electrode 5 mm in diameter, with j oscillations with an amplitude of 15 mm, at a different distance m at an optimal distance 1 equal to 16.5 mm. The deposited layer in samples I, 4, 7, 10 is uniform in appearance, non-porous, however, has a lower hardness due to a significant mixing of the molten metal of low-carbon electrodes with carbide compounds formed during

... ..- i.xj. j i..j u (/ Ш, П1ЧЛ Л Д У

surfacing weld including synthesis of 45 CB-synthesis in powder tape or

bath Teveppsh-smt mon pi,. „..JAvinit plp

Bathing carbide material located in a low-carbon matrix. A transition zone IV is formed, which allows the carbide material to be firmly bonded. I

Example. The deposition was carried out on a progressively moving sample using a welding machine (type А384МК) and power sources VDU-504. Wire PP-AN120 with a diameter of 3.5 mm was used as low-carbon electrodes. For surfacing used powder

electrodes. The deposited layer in samples 3, 6, 9, 12 has a high hardness, however, due to the high content of carbide compounds

50 in the middle of the weld seam in it

pore formation occurs. The weld layer in samples 2, 8, 11 is uniform in appearance, without pores with high hardness in the middle of the surfacing one.

55 stitches. I

When working parts, hardened by the proposed method, in conditions of friction in abrasive rocks hard alloy1602642

tape 8 and 10 mm wide and 2 mm thick and powder electrodes with a diameter of 5 mm. A powder mixture capable of self-propagating high-temperature synthesis was used to fill the powder tape and the electrode.

The method was carried out according to the described operations. In this case, the speed of movement of the part (sample) was equal to 6 mm / s. The oscillation amplitude of the powder electrode is 15 mm. The quality control of the deposited layer was carried out by measuring the hardness of TP-7P-1 by the Vickers method, estimating the percentage of pores and the uniformity of the deposited layer.

Data on surfacing 12 samples

are shown in the table.

 Samples 1-3 were deposited

8 mm wide tape with different distances between the centers of low-carbon electrodes t, calculated

(. III j / dv, Mi-l 1 ousasmim

from the formula. Samples 4-6 were deposited

the same tape, but with a different distance between the center of the electrodes and the cross, the center of the powder tape 1.

Samples 7-9 were fused with 30 powder tape with a width of 10 mm for various

distance m and the same 1, which coincides with the optimum in the previous surfacing. Samples 10–12 were deposited with a powder electrode 5 mm in diameter, with j oscillations with an amplitude of 15 mm, at different distances m at an optimum distance 1 equal to 16.5 mm. The deposited layer in samples I, 4, 7, 10 is uniform in appearance, non-rusty, however, it has a lower hardness due to a significant mixing of the molten metal of low-carbon electrodes with carbide compounds formed during

... ..- i.xj. j i..j u (/ Ш, П1ЧЛ Л Д У

45 CB-synthesis in powder tape or

 ..JAvinit plp

electrodes. The deposited layer in samples 3, 6, 9, 12 has a high hardness, however, due to the high content of carbide compounds

0 in the middle of the weld seam in it

pore formation occurs. The weld layer in samples 2, 8, 11 is uniform in appearance, without pores with high hardness in the middle of the surfacing one.

5 seam. I

When working parts strengthened by the proposed method, under conditions of friction in abrasive rocks, the carbide layer protects the surface of the part from wear, and peripheral welding with low-carbon wire prevents the carbide layer from chipping under conditions of significant alternating stresses.

The method makes it possible to obtain weld surfaces with good quality, with the maximum possible doping levels (especially refractory compounds), and to achieve such a hardness of the material that it is impossible to achieve by traditional methods of surfacing.

Claims (3)

Invention Formula G, Method of surfacing wear-resistant alloys, in which three electrodes are used, two of which are installed symmetrically with respect to the axis of surfacing, and the center of the third is set along the axis of surfacing, which differs so that, in order to increase the wear resistance of the deposited layer of the deposited product by reducing the residual stresses, the first two electrodes of mild steel with diameter d are set with a distance t from each other, depending on the size of all electrodes, and create two independent welding Baths, and the third electrode, containing a mixture capable of self-propagating high-temperature synthesis, is set at a distance from the line of low-carbon electrodes in the direction opposite to the deposition direction, with the specified distance being chosen depending on the size of all electrodes and the deposition rate. 2. The method according to claim 1, about tl and h and yu and with the fact that the third electrode is chosen with a strip width of c and thickness, while the distance between low-carbon electrodes ha is chosen within the following limits: m (c + d + l) i2, mm, and the distance 1 from the axis of low-carbon electrodes to the ribbon electrode is established from the relation: , 5 (d + b) + - 4d + KV + 2, mm, where V is the speed of the relative movement of the weld piece and electrodes, mm / s, K 1, 5. o .. 2 s. 3. The method according to claim 1, characterized in that the third electrode is selected with a wire with a diameter e, the electrode is given oscillations with amplitude A, the distance m is chosen from the ratio m (e + d + A + l) ± 2, mm, and distance 1 is selected from the ratio, 5 (d4-e) +, fd + KV + 2, mm. Phage.2