SU897459A1 - Method of obtaining grooves in piston ring blanks - Google Patents

Description

one

The invention relates to welding and is intended to obtain grooves in the piston rings of piston machines, such as the pistons of internal combustion engines.

A known method of producing grooves, according to which, in the body of the piston, a groove is preliminarily bored, the dimensions of which exceed the dimensions of a given groove. After that, the piston is heated to 200 ° C and the intermediate layer (sublayer) of nickel aluminide is sprayed, then a base layer of wear-resistant material is applied to the specified sublayer until the groove is completely filled. For example, stainless steel is used as a wear resistant material. After spraying, a groove of the required dimensions is machined. material and final groove grooves.

There is also known a method of producing grooves in piston ring blanks, according to which the piston blanks are preheated to the melting zone of the groove with the introduction of alloying material and the groove grooves after cooling the blanks f Sj.

ten

The disadvantages of this method include the technological complexity caused by. required by the preliminary 1C) otochkn grooves in the body of the piston, and the poor quality of fusion of the weld

ts of the hardening layer with piston metarial, the presence of welds, pores and other welding defects.

The purpose of the invention is to reduce the complexity of the process and increase the quality

30 grooves.

This goal is achieved by the fact that according to the method of obtaining grooves in the billet piston rings melting

389

The plasma arc is produced at a depth of 0.5-1.3 at a given groove with a ratio of welding speed to feed rate of alloying material of 0.75 - 1.85, and in the process of melting the workpiece is cooled with compressed air.

The method for producing the grooves for the piston rings is carried out as follows.

The blank is heated and the temperature is kept constant during the melting process (by blowing with compressed air), then the metal volume is melted in the future groove with a plasma arc and at the same time the alloying material is introduced, for example nickel. Then the piston is cooled and the groove of a given size is machined. In this case, the groove zone is produced, depending on the diameter of the core (dimensions of a given groove) at a depth of 0.5-1.3 depths of a given groove, and transition materials or their alloys (nickel, nickel chromium, aluminum) are used as alloying materials. nickel-chromium, etc.) In order to ensure uniform dissolution of the alloying material in the melted layer, the filler wire is fed at a rate

VCB / Vnp-aTsr-f F /

where VCB is the rate of penetration;

V - alloy feed rate

g wire.

The proposed method of strengthening the grooves of the wheels is implemented in the manufacture of aluminum plates 0 150 and 210 mm for diesel engines 6ЧН 15/18 and

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6411 21 / 2J. In this case, the preform blanks are preheated to 2OOc. Then, in the area of the groove under the first compression ring, the plasma arc with a velocity

13-O, 5 m / h, the volume of the metal is melted to a depth of 6.5 4-O, 3 mm, which corresponds to 1.1 from the depth of the groove for thickened 0 150 mm and 0.8 from the depth of the flute for thickened 0 210 mm.

Simultaneously with the penetration, the alloying material (in the form of DB-NI wire) is introduced into the weld pool at a speed of 14 m / h, which corresponds to a Vcg / V p ratio of 0.93. To achieve

nor the same depth of penetration

Along the length of the circumference and overheating of the material of the workpiece, the temperature of the blank of the substrate in the process of melting is kept constant (175 + 25 C). WITH

To this end, in the process of penetration, the blank is cooled by compressed air with a temperature of 20 ° C. After cooling the piston blank, a metallographic examination of the resulting alloy is carried out before the flow groove.

Studies show that when melting with the introduction of nickel, the structure of the molten metal fine-grained, lack of penetration. Number of pores

does not exceed 0.2% of the volume of the material melted. The transition zone of fusion with the base metal of the core smoothly passes from one structure to another. The resulting alloy

has 8 to 9% nickel by weight of the molten metal,

The table shows the results of comparing the hardness of the piston alloys AK-4 and AL-25 and the deposited alloy.

Melted

140-160 metal. After the zone of the grooves has been melted, the core is cooled to room temperature and then the groove of the predetermined groove is made. Test pistons with hardened grooves on diesel engines CHN 15/18 and CHN 21/21 show that the wear of the grooves is reduced by 4-6 times.

27 -OZ The advantage of the method of hardening grooves for piston rings is to increase the wear resistance of the piston grooves of the pulses by 4-6 times, which significantly increases the lifespan of the diesel piston group. The economic effect from the introduction of the proposed method only on diesel engines of the type CH-ChN 15/18 is 1.3 1.5 million rubles.

5897459 "

Claims (2)

Claim 1.3 of a predetermined groove depth Paemen Method for obtaining grooves in workpieces to the feed rate of the pegirukypets of piston rings, at which it produced 0.75-1.25, and in the process Water t preheating the billet- $ melted down the billet is compressed I pi of the piston until melting zone ka-air. navki with the introduction of the doping mother - Sources of information ala and groove grooves after cooling are taken into account during examination. billet, characterized in that 1. UK patent that, in order to reduce the labor intensity of Pro. # 132648О, кп. 23 r 17/00, 1975. process and improve the quality of the grooves, 2. US patent number ZO14771, melting is carried out at a depth of 0.5 cells. ZO9-14, 1966. Noah arc with the speed of welding