SU1401740A1 - Method of induction buildup - Google Patents

Abstract

The invention relates to surfacing technology and can be used in induction welding with hard alloys of various products, for example, working bodies of tillage machines. The goal is to reduce energy consumption by reducing the Tevpneura- tion of heating the base metal and increasing the productivity of the process. The powdery deposition charge is mechanically activated without comminution before it is applied to the weld surface. Mechanical activation of fir without grinding increases the level of free energy in it. Some of the energy is released directly in the charge layer. Its thermal conductivity increases, which reduces the time of melting of the charge and reduces the heating temperature of the base metal, the lawsuit; it must be put down to overheat, and energy consumption is reduced. 1 il. (L

Description

The invention relates to. surfacing and can be used for inductive hard-facing welding of various products, for example, working bodies of tillage machines.

The purpose of the invention is to reduce the heating temperature of the base metal and reduce energy consumption due to an increase in the performance of the deposition process.

The essence of the described method is that the powdered surfacing charge is mechanically activated without grinding, then applied to the weldable surface of the part, heated and melted with an inductor.

This method uses mechanical activation without disturbing the granulometric composition of the starting powder. For this purpose, special activator apparatuses are used in which the energy of the collision of the particles with the substrate and the number of collisions for the particles are regulated. In the case of an essm, a non-destructive two-phase treatment mode is selected. It is also possible to ensure activation in a planetary mill in the selection of grinding bodies, and: with diameters and total mass, as well as processing time.

Mechanical activation of the charge without its grinding increases the level of free energy in it. This leads to the fact that some of the energy is released directly in the layer of the charge, its thermal conductivity increases, the time it melts decreases, the heating temperature of the base metal decreases, its overheating is eliminated, the energy consumption is reduced

The drawing shows thermograms of the process of surfacing activated and non-activated 2 materials NA 14-80. Thermograms are taken with one device, with the help of one thermocouple, which is welded by a contact method to the surface being welded. Surfacing was carried out on the same mode of the HDTV generator. On the thermogram, the presence of a shelf in area A indicates the formation of a liquid phase and the end of the surfacing process. The process time F is shortened.

Examples Whether the ploughshare has melted. As a surfacing material, a US-25 alloy was taken. Powder indicated1

i

-

-

Sh

15

20

25

thirty

35

40

45

50

55

This alloy was subjected to mechanical activation in a planetary mill connected to an electric motor with a He power of 5.1 kW.

The activation mode is as follows:

rotation speed of the drive wheel of the planetary mill rpm;

drum speed Uj 700 rpm;

mass of balls with a diameter of 8 mm 250 g;

the mass of the material processed in the drum is 50 g;

the time of the 1st activation phase is 5 s;

rest time 5 s;

time of the F-th phase of activation I5 s.

The two-phase activation mode with a five-second interval between phases, established experimentally, ensures that the activation is carried out without grinding the charge material, which is a necessary condition for the release of some free energy in it.

After activation of the charge, it was applied to the weld surface of the plowshare with a layer of 8 mm

Surfacing mode is as follows:

66 kHz oscillator frequency;

power output N 100 kW;

temperature on the metal substrate T 1050 1HOOCH;

deposition time (28 s.

A similar plowshare using the same surfacing parameters, but without prior activation of the charge, was deposited to determine the advantages of the proposed method. It was found that the temperature on the metal substrate T 1200-1250 C;

deposition time from 37 s.

Whether the field board has been deposited. PS14-8 alloy was used as a filler material. The powder of such an alloy was subjected to mechanical activation in a planetary mill.

The activation modes were the same as in the first example, except for the time of the nth phase:. It was 5 seconds.

The surfacing modes were similar with the exception of the temperature / ry on the metal substrate, which was maintained at a level of T 1040-1080 s.

I

The deposition time in the second example was 14 s.

The same field board with the same deposition parameters, but without preliminary activation of the charge (for comparison) was melted at a temperature of

 / 140 to the substrate of the metal T 1200-1250 ° С during the time of Tnd 21 s.

Thus, pretreatment of the charge with the purpose of its mechanical activation without comminution makes it possible to shorten the Ploughshare cladding time 9 s or 24% compared with the prototype, and the time required for surfacing the floorboard by 7 s or 33%. It should also be noted lowering the temperature of heating of the sub-metal from 200 to 1050-1100 C in the first case and to 1040-1080 C in the second.

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Claims (1)

Invention Formula The method of induction surfacing, which includes heating and melting of the powder mixture onto the surface being welded, melting and melting, in order to reduce energy consumption by lowering the heating temperature of the base metal and increasing the process efficiency, the porous mixture is mechanically pre-activated without grinding ;