METHOD OF MAKING WEAR-RESISTANT BARRELS OF FIRE-ARMS FIELD OF THE INVENTION
The present invention relates to the defence technique, and precisely to manufacturing of infantry-gun arming and can be used for repair-restoration operations. BACKGROUND OF THE INVENTION
The problem of arming vitality, particularly vitality of the barrels acquires large importance as manufacturing of arming has a mass scale. The question about vitality of the barrels is of extreme importance, as at present time a barrel is the most short-lived detail among the responsible details of weapon. Sometimes the duration of an automatic device service is ten times more, than vitality of one barrel . This disproportion is the reason of paying serious attention to the barrels vitality. Pressure and temperature of the gunpowder gases; pressure of the projectile on lateral edge of a groove; friction on barrel surface during moving of projectile (bullet) along of a groove are the principal reasons, which cause the barrels wear [Blagonravov A.A. Material part of the fire-arm. Book l.
- M. : Oborongiz, 1945, p. 23 - 41; Orlov B.V. Projecting of the rockets and barrels systems. - M. :Mechnical-engineering,
1974, pp. 323 - 373; Orlov B.V., Larman Z.K., Malikov V.G.
Device and projecting gun tube.- M. :Mechnical-engineering,
1976.- 431p.] .
Weapon vitality is measured by the quantity of shots made by a weapon before the essential changes of weapon
quality take place. They are determined by measuring a close grouping of shots and by determining the cases of tearing bullets from grooves which conduct to a wrong flight of a bullet and etc.
Searching for means of decreasing barrel wear, first of all a lot of attention was paid on searching for the sorts of special steels which provide higher vitality of the barrels. There is a row of the sorts of special steels which are sufficiently resistant to wear. The special steels, which have in their composition such elements as Cr, Ni, W, give some rise of vitality. However the technological difficulties during the use of special sorts of the steels in comparison with an insignificant rise of the barrel vitality make searching for other methods of a rise vitality of the barrels.
The special treatment of surface bore of barrel is concerned to those methods, it is precisely the precipitation of a chrome layer on a surface, the special condition of a surface case-hardened bore of a barrel; the rivet, added to a surface layer of a metal, that give higher hardness to a surface of a bore . Sometimes through the use of such methods the barrel vitality may be raised in 1,5 time [ Blagonravov A.A. Action o tube. - L. : Publishing house of the Artillery Academy RKKA, 1933, pp. 2 - 49 ] .
However in case of the use of the above mentioned methods the expenses on their realization are not justified by a level of rise vitality in most cases.
It is known the method of making wear-resistant barrels of fire-arm [description to RU patent No. 2066821, 20.12.93, IPC F 41 A 21/00 ] , which includes thermal rise of hardness of a part of a barrel and the subsequent pressing of casing
on the barrel, in which the whole metal of the barrel breech including the cartridge-chamber and beginning grooving part on the length not less than three calibre are put to thermal treatment for rise hardness; then the casing is pressed on the part with higher hardness and the casing overlaps this part on a length not less than one calibre.
Manufactured by such a method, a barrel has high hardness of a material in part where thermoplastic wear takes place (the beginning of a groove part) and subsequent constructive hardness for its making under strengthen scheme (presence of a pressing casing) .
However the described method essentially rises the cost of a product, and can't be used for repair-restoration operations and besides it requires the use of special equipment .
The nearest to declared decision for setting, technical essence and the result which must be reached during the use, is the method of smearing a bore of a fire-arm barrel which includes cleaning and drifting of protective layer by ultradispersion powder [description to RU patent N 2074349, 22.07.93, IPC F 41 A 21/00], in which a powder of tetrafluorineethylene is used as ultradispersion powder, and on the parts, which are not in friction connection, a neutral smearing layer is drifted on the protective layer of the ultradispersion powder of polytetrafluorineethylene .
As the control shots showed, after smearing by the known method, a close grouping of shots was 15 cm at the distance of 100 m, and after smearing by the offered method, the control shots showed a close grouping of shots not less than
5 cm at the same distance.
However the described above method of swearing a barrel, parts and mechanisms of a weapon solves the main problem from the point of view of corrosion protection because it protects a bore surface of a barrel during its 6 months storage even in the most hard exploitation conditions (rain, dirt, sweating) . The method does not solve a problem of rising a barrel vitality, because the action of swearing which contains the ultradispersion polite is limited by some cycles of shotings, after this it is necessary to repeat the procedure of swearing. It is connected with the circumstance, o that at temperature higher than 250 C it takes place the disintegration of a polytatrafluorineethelene with evolving of high toxic products, and their concentration rises at o temperature higher 415 C [Polymer encyclopaedia. V.3 - M. :
S.E. , 1977, p.644 - 648] .
The last circumstance excludes the use of powder of polytetrafluorineethelene for treating the barrels of automatic weapon, which must be used in closed or limited spaces, for example in a turret of a tank, in which it is possible that gases are concentrated after shots have been done.
SUMMARY OF THE INVENTION
Therefore the task of the offered technical decision is to rise fire-arms vitality, and in addition to expand functional possibilities by the use of this method both for corrosion protection and for the technical characteristics of a fire-arm barrel improvement, reducing the expenses on restoration of battle and operating characteristics of a fire-arm.
The basis of the invention is the problem of improvement of the method of making wear-resistance barrels of fire-arms, in which, in consequence of the treating by the ultradispersion powder or by^the mixture of ulttradispersion powder and technological medium fulfilled before each gunshot of a set, which consist of not less than 3-5 shots, by means of drifting ultradispersion powder or its mixture with technological medium on the outward surface of the each projectile and on the inside surface of a barrel, with that the ultradispersion powder is prepared of the natural mineral or the mixture of the natural minerals, which is chosen from the flaky silicate row, including the different structural modification of the composition Mg [ Si 0 ] (OH) , it is
3 2 5 4 provided modification of an inside surface of a barrel with the specific metal-ceramics phases formation, which are resistant to corrosion and wear, and at the expense of that a rise of ballistic characteristics of fire-arm takes place, and it is expressed in a rise of gun long-rang and killing power, and also in a rise of close grouping shots which remains for a long time, that is the rise of the characteristics, which determine weapon vitality.
The raised problem is solved so that in the known method of making wear-resistant barrels of fire-arms, including preliminary cleaning and treating by ultradispersion powder, according to the invention, the treating by the ultradispersion powder or by the mixture of ultradispersion powder and technological medium is fulfilled before each gunshot of set, which consists of not less than 3-5 shots, by means of drifting ultradispersion powder or its mixture with
technological medium on the outward surface of the each projectile and on the inside surface of a barrel, with that the ultradispersion powder is prepared of the natural mineral or the mixture of the natural minerals, which is chosen from the row of a flaky silicate, including the different structural modification of composition Mg [Si 0 ] (OH) .
3 2 5 4 According to preferred embodiment of the invention the content of the natural mineral or the mixture of the natural minerals in a technological medium takes not less than 1,0-
1, 5 g/ml .
According to another embodiment of the invention the quantity of the shots in the set and the content of the ultradispersion powder in the technological medium is mounted depending on the condition of inside surface of a barrel . It may depend on work cleanness of the inside surface of a barrel or on a wear degree of a barrel, if the method is used for repair-restoration operations, it also depends on a weapon calibre and the other peculiarities.
As it is seen from the description of the technical decision, which is declared, it is distinctive from the prior art and consequently it is new.
The decision has also the inventive level. It is known utilisation of a repair-restoration composition on a base of the natural minerals for treating of a cylinder-piston group by means of introduction of the technological composition in an engine over piston level [description to UA patent No. 24442 A, 22.04.97, IPC C 10 M 125/40] . Then without putting of the oil burners, a crankshaft was revolved during 20 min with the help of a hand gear. After that the oil burners were put on and the engine was started up as usually. After 65
hours of engine work it was noticed, that the quantity of crankcase fumes was essentially reduced, that was the evidence of the whole renewal of the cylinder-piston group. In the above-mentioned technical decision visible tribotechnical effect and restoration of the friction zones are connected with a certain quantity of the amorphous silicon dioxide and the presence of the catalysts on the basic of schungite and rare-earth metals, which lead to generation of special metal-ceramics layers, which provide reaching of the above-mentioned positive properties . Tribotechnical effect is reached and restoration is completed at temperature and pressure, which exist, when oil burns down in an engine .
It is also known the use of a substance as a hard lubricant covering, which contains a sticker and the natural mineral mixture with dispersion less than 10 mem [description to RU patent No. 2043393, 25.09.91, IPC C 10 M 125/04]. In this case a final antifriction fettling was made at room temperature that provided unlimited capacity for work of triads of friction and wear absence of an immovable model
C421-40 under pressure 6,0 - 13,5 mPa and the speed 0,3 m/c. o However if the natural mineral mixture is heated until 1500 C the reaction of diserpentinization takes place and quartz, fluorsulfur and pyroxene are their products. These substances do not form the mirrors of sliding.
As it is seen from the descriptions of the known technical decisions, which use the natural minerals or the mixture of the natural minerals, the conditions of their use for a surface modification and the use of the modified
surfaces essentially differ from the applicant decision. The wear-resistance barrels are manufactured at the presence of higher temperature and more complicated dynamical loading, which are realised in a barrel as a result of gunpowder pressure and a projectile moving at a large speed.
Nevertheless, as the result of realisation of the offered method the steady modification of the barrel inside surface is observed, which is displayed as an improvement of barrel ballistic characteristics and vitality rise.
The offered technical decision may be used in industry for modification of the fire-arms (shells) barrels during their manufacturing and restoration, as it permits to restore the ballistic properties of the weapon, which were lost in the result of exploitation.
USE OF THE INVENTION
The results of the application of the offered method are illustrated by the following examples of the use of ultradispersion powder, which is the mixture of the natural minerals; for example not less than 90% ophite, with the dominate structural modification of composition
Mg [Si 0 ] (OH) . 3 2 5 4
The first example. The barrel of a small-calibre rifle
5,6 mm was cleaned from factory lubrication. The barrel was settled on a test bench at the distance of 50 m from a target and 10 control shots for the determination of a close grouping of shots were done. For the barrels of such class the registration certificate data are not less than 7,5 mm.
From the ultradispersion powder of the natural mineral, the above mentioned composition was prepared, the suspension in which 1,0 g of the powder was π ςed with 1,0 ml kerosene or
white-spirit and etc. It was drifted uniformly on the barrel inside surface and the bullet outside surface before each shot . The whole expense of the ultradispersion powder was 2 g. After the set of 3 shots a close grouping of shots was not less than 4 cm and retained after 1000 shots without the additional protective treatment from corrosion.
The second example. The barrel of a small-calibre rifle 5,6 mm, which was in exploitation for a long period of time, was cleaned from lubrication and other dirt. The barrel was settled ona test bench and 10 control shots for the determination of a close grouping of shots were done. The above-mentioned composition, suspension was prepared from the ultradispersion powder of the natural mineral and kerosene, and it was drifting uniformly on the above-mentioned surfaces before each shot. The whole expense of the ultradispersion powder was 20 g after the set of 30 shots. At the initial close grouping of shots 9,5 cm, after the set of 30 shots a close grouping of shots became not less than 4 cm and retained after 1000 shots without the additional protective treatment from corrosion.
The third example. The gun tube with calibre 128,5 mm, which was in exploitation for a long period of time, was cleaned from lubrication and other dirt. Five control shots were done for the determination of a close grouping of shots. The above-mentioned composition, suspension was prepared from the ultradispersion powder of the natural mineral. This suspension was drifted uniformly on the projectile outside surface and the gun tube inside surface on 2 m length before each sho . After a set of 10 shots a close grouping of shots
improved in 1,4 time, projectile distance of flight improved in 2 times. Attained indices of a close grouping of shots and projectile distance of a flight retained after 600 shots and more without any additional treatment.
The fourth example. The CKC-7,62 barrel, which was in exploitation for a long period of time was cleaned from lubrication and other dirt. The barrel was settled on a test bench and 10 control shots wear done for the determination of a close grouping of shots. After the control shots the additional shots were done to modify a barrel inside surface. Before of each shot out of 10 shorts the bullet outside surface and the barrel inside surface wear drifted by the ultradispersion powder. The expense of powder for modification was 6 g. At the initial close grouping of shots was 9,5 cm, after a set of 10 shots it became not less than 4 cm and retained after 1000 shots and more without the additional protective treatment from corrosion.
As it is seen from the descriptions of the examples of the method of realisation, the offered technical decision has wide functional possibilities, because it provides the rise of fire-arm vitality, which is displayed in the steady improvement of ballistic characteristics both new and having been in exploitation for a long period of time. Furthermore, the method is characterised by simplicity of its realisation and the possibility of reducing of the expenses for the restoration of fire-arm battle characteristics.