RU2693252C1 - Repair method of operational damages of railroad head rolling surface - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to repair of operational damages of rolling surface of railway rail head and is used for repair of railway rail laid on tracks of railway transport, trams, metro trains and on crane ways. Proposed method comprises cleaning of damaged surface with defect, heating of stripped section, layer-by-layer surfacing of cleaned section, natural cooling and machining of built-up surface. In zone, width of which exceeds width of weld zone by 250 mm, heating is performed, at that roller is welded on starting and ending on side of non-working face of rail on three sides of perimeter of repaired damage, then re-depositing roller along entire perimeter of repaired damage.

EFFECT: repair of electric rail surfacing of railway rails from high-carbon medium alloyed steel with weight content of chromium content to 1,25 %.

1 cl, 6 dwg

Description

The invention relates to railway transport, in particular to the technology of repair (restoration) of the railway rail, in the field of operational damage, classified as defects in the form of chipping of the metal and / or previously deposited layer, crumpling and saddles, located on the rolling surface of the head in the area of bolted joints, electric arc surfacing laid on the railways, trams, subway trains and subcrane tracks.

A known method of repairing castings with the use of arc welding, including cutting the edges for welding before removing the defective section, and after removing the defective section of the casting, preheating is carried out along the contour in the temperature range from 150 to 250 ° C, the overlapping rollers along the contour of the repaired defective section, the imposition intermediate layer by two-layer welding of metal with a thickness of 3 to 5 mm, the imposition of welded rollers carried out with an overlap of not more than 50%, the imposition of facing rollers along the contour emontiruemogo defect formed weld zone width not exceeding 25 mm, and cooling the weld joint (RF patent №2630080, IPC V23K 6/04 (2006.01) V23K 9/04 (2006.01) opub., the 09/05/2017).

This method cannot be used to restore and repair damaged rolling surfaces of a railroad rail, as it is intended for the repair of products from low carbon and / or low alloyed steels.

The closest to the proposed invention by the combination of essential features is a method of restoring worn surfaces that have defects in the form of proboksovok, in which carry out the cleaning of the damaged surface having a defect, grinding to complete its removal, heating the stripped area, layer-by-layer surfacing of the stripped area, natural cooling and mechanical treatment of the weld surface, heating of the bare area is carried out to a temperature of 400-450 ° C for 5-6 minutes along its entire length and about side of the site on the value of technological allowances, amounting to about 100 mm, (see RF Patent No. 2382695, IPC В23Р 6/00 (2006.01), В23К 9/04 (2006.01), Е01В 31/18 (2006.01), published 27.02.2010 ).

The known method due to insufficient heating temperature of the cleaned area and a small amount of technological allowances does not allow repairing the railway rail, made of high carbon medium-alloyed steel, with a mass fraction of chromium content up to 1.25%, inclusive, in the field of operational damage, classified as flaking defects metal and / or previously deposited layer, crumpling and saddles located on the surface of the head in the area of bolted joints.

The task of the invention is the provision of repair of arc welding of rail rails of high carbon mild steel, with a mass fraction of chromium content up to 1.25% inclusive, with damage to the rolling surface in the area of bolted joints due to the increased dynamic effects of wheels of rolling stock, trams, subway trains and cranes.

The technical result in the implementation of the invention is the provision of repair of arc welding of rail rails of high carbon medium alloyed steel, with a mass fraction of chromium content of up to 1.25% for all types of rail transport and crane mechanisms with the restoration of operational properties of damaged rolling surfaces in the area of bolted joints.

This technical result is achieved by the fact that in the proposed method, cleaning of the damaged surface having a defect, grinding until it is completely removed, heating of the scraped area, layer-by-layer surfacing of the scraped area, natural cooling and machining of the weld surface, and a welding zone plus 250 mm are carried out. heated approximately in the range from 455 ° C to 485 ° C using induction equipment equipped with an electronic process certification system or a gas-flame method using propane-oxygen or gas-air propane burners, while first melting the three-sided roller, starting and ending from the non-working the edges of the rail, around the perimeter of the damage being repaired, then re-weld the roller already around the perimeter of the damage being repaired, and the surfacing of the first layer and subsequent layers of the surface and carried out in the transverse direction over the entire width of the rail head, starting and ending on the side of the inoperative rail face, and the surfacing of the last layer is made with a bevel of approximately 45 °.

In addition, it is preferable that after each surfacing make cleaning its surface.

The method of repairing operational damage to the rolling surface of the rail head is illustrated by drawings.

FIG. 1 shows the grinding scheme of the damaged surface;

in fig. 2 shows the scheme of surfacing of the roller from point 1-4 on the perimeter (beginning);

in fig. 3 shows the scheme of surfacing of the roller from point 1–4 along the perimeter (end);

in fig. 4 shows the deposition scheme of the first layer;

in fig. 5 shows the scheme of overlapping of the previously deposited bead;

in fig. 6 shows the scheme of surfacing the last layer;

The method of repairing operational damage to the rolling surface of the rail head of worn-out rolling surfaces of the rail rail is carried out as follows.

Example 1

Standard equipment, such as welding equipment, electric generator, automatic machine, grinding equipment, heating equipment, etc., are used to perform work on electric arc cladding of railway rails made of high carbon medium alloyed steel with a mass fraction of chromium content up to 1.25% inclusive.

The cladding repairs rails that have defects on the head in the area of bolted joints with a length of more than 25 mm and a depth of more than 1 mm, and a length of up to 25 mm inclusive and a depth of more than 6 mm.

Before surfacing, the damaged surface of the rail, which has a defect, is mechanically cleaned before it is completely removed, avoiding arson, and the length of the section being cleaned considerably exceeds the length and depth of the damaged surface of the rail (Fig. 1), where

K - the length of the polished area in the defect at the rail head;

P - the depth of the sanding area in the defect at the rail head;

L is the length of the transition zone, and L≥2P.

The surfacing zone (bare area) plus 250 mm at the rail head is heated approximately in the range from 455 ° C to 485 ° C, the heating temperature is measured with a digital small-size thermometer or pyrometer along the entire profile of the rail head for the length of the heating zone. For heating the surfacing zone, induction equipment equipped with an electronic certification system of the process is used; in the absence of induction equipment, a gas-flame method using propane-oxygen or gas-air propane torches is used.

After heating the bare rail section, mechanized surfacing is performed, consisting in that the three-sided roller is first deposited, starting and ending on the side of the non-working edge A of the rail along the perimeter of the damage being repaired (FIG. 2) - positions 1, 2, 3, 4. self-shielded cored wire.

Then they beat off the slag with a welding hammer and clean the place of surfacing with a metal brush. Next, weld the roller around the perimeter (positions 1, 2, 3, 4) of the repaired damage (Fig. 3), beat off the slag with a welding hammer and smooth out the place of surfacing with a metal brush.

The first layer of surfacing is produced in the transverse direction over the entire width of the rail head (positions 1, 2, 3, 4) (Fig. 4), starting from the non-working face A, with the previously welded bead overlapping 1/3 (Fig. 5) without undercuts and irregularities where

S is the width of the previous roller;

D is the overlap width of the previously deposited bead, with D = S / 3.

The second and subsequent layers are fused in the same way as the first layer, with the last layer being fused with a bevel of about 45 ° (Fig. 6).

In the case of lowering the heating temperature below 455 ° C, the surfacing zone is reheated to the desired temperature.

The rolling surface after surfacing on the rail head is mechanically processed in accordance with the transverse profile of the non-weld part of the rail. The deposited rails are treated with an abrasive tool after they are naturally cooled to a temperature of about 35-45 ° C, if after the completion of surfacing work the ambient temperature is below 10 ° C, the surfacing zone is covered with mineral wool for several minutes.

If, after finishing the work, visual pores, undercuts, inconsistencies are detected in the surfacing zone, then the defects are cleaned with an abrasive tool followed by surfacing.

Example 2

Surfacing of the stripped portion of the rail surface can be carried out automatically by means of a surfacing machine, which is mounted on the rail head with quick-release clamps. The operator (welder) from the control unit sets the surfacing program, the procedure for surfacing the first and subsequent layers is the same as in Example 1.

When approaching a rail vehicle or a crane, the operator stops the overlay with an emergency shutdown button and puts the machine into a safe area for rail traffic or a crane.

The claimed invention allows to expand the technological capabilities of the method of repairing damaged rolling rail surfaces, developed schemes for cleaning the damaged surface and surfacing of rollers and layers allows repairing defects in the form of chipping metal and / or previously deposited layer, crumpling and saddles located on the head rolling surface in the area of bolted joints, increasing the temperature of the weld zone (bare area) and increasing the length of the heated section allows for repairs electric arc welding of railway rails from high carbon medium alloyed steel, with a mass fraction of chromium content up to 1.25% inclusive.

The application of the proposed method provides: restoration of the operational properties of the damaged rolling surfaces of the rails, saving the operating costs of the owner of the transport and crane infrastructure for the complete replacement of the rail, for limiting the speed of movement of the rail transport, skipping up to 250 million tons. gross cargo with preservation of the required performance properties.

Claims (2)

1. A method of repairing operational damage to the rolling surface of a rail head, including cleaning the damaged surface that has a defect, grinding to its complete removal, heating the bare section, layer-by-layer surfacing of the bare section, natural cooling and machining of the weld surface, characterized in that the width of which exceeds the width of the deposition zone by 250 mm, they carry out heating up to 455-485 ° С, at the same time first they roll up the roller, starting and ending it from the non-working side rail, on three sides of the perimeter of the repaired damage, then re-weld the roller around the perimeter of the repaired damage, and then perform surfacing on the entire width of the rail head, and the surfacing of the first layer and the subsequent surface layers is carried out in the transverse direction on the entire width of the rail head, starting and ending on the side of the non-working face of the rail. 2. The method according to p. 1, characterized in that after each surfacing make cleaning its surface.

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