SU1244204A1 - Method of treating metallization self-fluxing coatings - Google Patents

Description

The invention relates to the deposition of gas-thermal methods of water, in particular to the melting of gas-thermal coatings from self-fluxing alloys, and can be used in various fields of engineering.

The purpose of the invention is to reduce warpage of parts with pokryp.

According to the proposed method, the coating is first melted in a continuous strip along its perimeter, and further melting is carried out by sequential alternation of the melted and non-melted portions of the coating from the edges of the part to the center.

A solid melted strip is obtained by simultaneously melting all the boundaries of the coating, and the area of this band is 5-15% of the total area of the coating; during the melting of coatings on parts operating under reciprocating conditions, the central part of the coating with an area of 5–15% is left unmelted; the melting of coatings on parts operating under rotational motion conditions is carried out by sequential alternation of melted and non-melted radially opposite sites, the central part of the coating with an area of 5-15% is left unmelted.

When the coatings are melted in the specified sequence, the residual stresses are redistributed over the entire surface and part volume, which reduces its distortion

A solid melted strip along the boundary of an area of not less than 5% of the coating area creates such a tension of the substrate that the residual stresses that occur in the coating during the zonal melting of sections can no longer cause significant distortion of the part.

With a stripe area of more than 15%, an increase in the distortion of detail is observed1244204

15% unacceptable due to reduced wear resistance of the coating.

The invention is carried out as follows.

5 Sprayed onto the part a coating of a self-fluxing alloy, for example, a plasma torch, then the coating is melted in the indicated sequence by a suitable source.

10 heating, such as a gas burner.

Example. A self-fluxing grade PG-CP4 alloy coating was sprayed onto plates measuring 125x70 mm and 4, 6, 8 mm in thickness made of steel 45.

(5 The surface to be coated was pre-shot blasted.

The coated parts were heated to 1150 K and then at 1320 K

20 made a reflow burner Moscow.

The total area of the melted areas of the coating was within 60–85%.

25

YU

35

40

45

In this case, some plates were fused alternating between fused and non-melted areas, starting from one edge of the product to another, as in the well-known solution, while others were melted in accordance with the proposed method: first a continuous strip was melted along the edges of the processed plates, and then The process of melting was by gradual alternation of melted and non-melted areas of the coating from its edges to the center without melting of the central part of the coating with an area of 5–15%. .

Observed varying degrees of warping of melted parts, depending on. comparable technological methods of processing metallization coatings.

The buckling of the plates with melted coatings after they were cooled at a rate of 200 degrees / hour was determined by the following method.

The plate was installed on the test plate face down. A stand with a dial indicator was installed on the same plate. The measuring tip of the indicator was moved along the non-dusted side of the plate in two mutually perpendicular directions. The difference between the largest and smallest indications of the indicator was taken as the amount of warping of the measured plate. Wednesday

Is it already in the process of melting such a band?

The presence of a non-melted central part of the coating with an area of at least 5% has a positive effect on the redistribution of residual stresses, which leads to a decrease in the distortion of the part.

Increasing the area of the non-melted central part to a value of more

In this case, some plates were fused alternating between fused and non-melted areas, starting from one edge of the product to another, as in the well-known solution, while others were melted in accordance with the proposed method: first a continuous strip was melted along the edges of the processed plates, and then The process of melting was by gradual alternation of melted and non-melted areas of the coating from its edges to the center without melting of the central part of the coating with an area of 5–15%. .

Observed varying degrees of warping of melted parts, depending on. comparable technological methods of processing metallization coatings.

The buckling of the plates with melted coatings after they were cooled at a rate of 200 degrees / hour was determined by the following method.

The plate was installed on the test plate face down. A stand with a dial indicator was installed on the same plate. The measuring tip of the indicator was moved along the non-dusted side of the plate in two mutually perpendicular directions. The difference between the largest and smallest indications of the indicator was taken as the amount of warping of the measured plate. The average plate warping rate is calculated as the average arithmetic value of the measurement results with an accuracy of 0.01 mm; the warping values of a batch of plates of the same thickness (not less than 5 pcs.).

The measurement results are presented in the table. Plate thickness, mm

The average amount of warping, mm, according to the method

the famous

4 6 8

0.53 0.38 0.24

Thus, the invention makes it possible to significantly reduce the distortion of parts with melted coatings of self-fluxing alloys.

 This makes it possible to recommend the invention for use: in the screw industry, in particular for flat parts working in pairs.

Average percent reduction

I

proposed

0.22 0.21 0.17

60 45 30

Claims (4)

1. METHOD OF PROCESSING METAPLIZING COATINGS FROM SELF-FLUIDING ALLOYS by melting 60-85% of the coating area, characterized in that, in order to reduce warpage of coated parts, the coating is melted first by a continuous strip along its perimeter, and further melting is carried out sequentially plots of coverage from the edges to the center. 2. The method according to p. ^ Characterized in that a continuous melted strip is obtained by simultaneously melting all coating boundaries, the area of this strip being 5-15% of the total coating area. 3. The method according to PP. 1 and 2, characterized by the fact that when melting coatings on parts, I work. Under conditions of reciprocating motion, the central part of the coating with an area of 5-15% is left unmelted. 4. The method according to PP. 1 and 2, characterized in that the melting of the coatings on parts operating under rotational conditions is carried out by sequential alternation of the melted and unmelted radially opposite sections and the central part of the coating with an area of 5-15% is left unmelted. * 1244204