RU2254312C1 - Spherical retarded gunpowder for submachine gun and rifle cartridges - Google Patents

Abstract

FIELD: explosives.

SUBSTANCE: invention provides spherical retarded gunpowder consisting of spheroidally-shaped gunpowder grains with retarded surface layer containing nitrocellulose, nitroglycerin, ethyl acetate, Centralite no.1, diphenylamine, water, and retarding agent selected from dibutyl phthalate, dioctyl phthalate, diethyl hexylphthalate, triethylene glycol bis-methacrylate, oligoether acrylate, and their combinations. Thickness of retardant layer in gunpowder grain is S = 55-0.0312D (μm) wherein D is diameter of gunpowder grain. Concentration of retarding agent in retarded surface layer is 8-20 wt % and combustion heat is found from formula: Q = 685 + 0.244D.

EFFECT: increased bullet speed at the same maximum powder gas pressure.

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Description

The invention relates to the field of powder materials science and can be used in the manufacture of gunpowder for small arms cartridges.

Currently, work is underway in Russia and leading foreign countries to improve and develop new gunpowders for small arms cartridges. One of the priority directions in this area is to increase the ballistic efficiency of PSO due to the development of new propellant charges and high-energy progressively burning gunpowders.

Powder for machine guns and rifle cartridges, such as 5.45 mm × 39, 7.62 mm · 54, 5.56 mm “Remington 223” and 7.62 mm “Winchester 308”, are in great demand among domestic manufacturers and various foreign companies. .

It is known that for these cartridges a large number of grades of monobasic pyroxylin powders and dibasic spherical powders are used (1-2).

The disadvantage of monobasic pyroxylin powders is their low energy performance, associated with the ultimate capabilities of nitrocellulose.

Therefore, to obtain higher energy parameters of the shot using dibasic spherical gunpowder.

Known dibasic spherical powder for rifle and submachine gun cartridges manufactured by Olin (USA) and described in the book Accurate Smokeless Powder, 1994, 346 p. (2).

This gunpowder brand 2520, which is used in cartridges "Winchester 308" and machine gun cartridges "Remington 223".

This powder contains the following components, wt.%:

Nitrocellulose balance Nitroglycerine 8.0-11.0 Dinitrotoluene 1,0 Sodium sulfate <0.1 Potassium nitrate <0.5 Calcium carbonate <1.0 Ethylcentralite <7.0 Moisture and residual solvents 0.75-1.50 Graphite <0.4

The main physicochemical and ballistic characteristics of the composition are given in table 2,3,4.

The closest in composition and technical characteristics to the claimed one is dibasic spherical gunpowder grade SSNf 30/3, 69, produced by the domestic industry according to OST V-84-2432-89 (3).

This powder is selected as a prototype.

Phlegmatized gunpowder containing nitroglycerin is intended for small arms cartridges with an average burning arch size of 0.3 mm, with a specific heat of combustion of 880 ± 25 (kcal / kg), and an average grain diameter of 0.60 ± 15.

Powder grains have a spheroid shape with a phlegmatization surface layer.

Gunpowder on the prototype has the following composition:

Nitrocellulose 79.0 ± 4.0 Nitroglycerine 12.0 ± 1.5 Centralit No. 1 5.0 ± 1.0 Dinitrotoluene 1.8 ± 0.5 Diphenylamine 0.8 ± 0.3 Ethyl acetate 0.5 ± 0.4 Bonded graphite 0.1-0.3 Moisture 0.6 ± 0.3 Free graphite 0,03

The main physico-chemical and ballistic characteristics of this powder - the prototype are given in table.1.2.

The main disadvantages of the analogue and prototype is that they (gunpowder) do not provide a set of requirements for new generation cartridges. Firstly, the characteristics of the speed of bullets and the maximum pressure of the powder gases are not fulfilled or are fulfilled at the limit.

In addition, due to the non-optimal choice of the phlegmatizer, its distribution in the powder grain and the non-optimal thermodynamic parameters of the powders, poor performance on the stability of ballistic characteristics and the burning out of the powders at negative temperatures are observed. In addition, neither in the analogue nor in the prototype, the thickness of the phlegmatization layer and the content of the phlegmatizer in the layer are not determined.

The objective of the invention is to develop a new spherical powder, providing an increase in the speed of bullets without increasing the maximum pressure of the powder gases.

To solve this problem, spherical phlegmatized gunpowder for machine guns and rifle cartridges, consisting of spheroidal powder grains with a phlegmatization surface layer containing an energy base - nitrocellulose and nitroglycerin, ethyl acetate, phlegmatizer - centralite No. 1, chemical stability stabilizer - diphenylamine and water, as the phlegmatizer further comprises dibutyl phthalate and / or dioctyl phthalate and / or diethylhexyl phthalate and / or triethylene glycol dimethacrylate and / or oligoester acrylate, wherein the thickness of the phlegmatization surface layer has a value in microns: S = 55-0.0312D, where D is the diameter of the powder grains, and the concentration of the phlegmatizer in the phlegmatization surface layer is 8-20 wt.%, the heat of combustion of the powder in kcal./kg corresponds to the formula: Q = 685 + 0.344 D, in the following ratio of components, wt.%:

Ethyl acetate 0.3-0.7 Centralit No. 1 2.0-4.0 Dibutyl phthalate and / or Dioctyl phthalate and / or Diethylhexyl phthalate and / or Triethylene glycol dimethacrylate, and / or Oligoester acrylate 2.0-4.0 Diphenylamine 0.3-0.7 Water 0.2-0.6 Nitrocellulose rest

As the main direction for solving this problem, the principle of ensuring the progressive combustion of gunpowder and the approximation of the pressure distribution curve along the barrel channel to the plate-shaped one was used, which made it possible to increase the efficiency of the work performed by the powder gases. The process of gas formation and the efficient use of energy released during the combustion of gunpowder were controlled by the method of phlegmatization. The essence of the method consists in introducing substances into the surface layers of powder grains of substances that change their thermodynamic characteristics. This allows you to increase the specific energy of the charge from the spherical powder and the speed of the bullet at a constant, regular pressure level of the powder gases.

This effect was known (4); however, the achieved ballistic effects by means of phlegmatization were insignificant. Theoretical and experimental studies of the authors showed that the control of the ballistic process by creating stable gradient zones of gunpowder - phlegmatizer has great prospects for increasing the efficiency of the shot.

The essence of the invention lies in the fact that for gunpowder to machine guns and rifle cartridges, the optimum allowable diameter size to the thickness of the burning vault of powder grain was found. In this case, the ratio of the caliber of the cartridge to the thickness of the burning dome should be within 19 ... 21. The optimum thickness of the layer of the phlegmatizer in the powder grain should be determined by the dependence: S = 55-0.0312 D, where D is the diameter of the powder grain in microns. The optimum concentration of the phlegmatizer in the layer should be in the range of 8-20 wt.%. In this case, the heat of combustion of the powder increases with increasing grain diameter in accordance with the experimentally found dependence:

Q = 685 + 0.344 D.

To ensure these conditions experimentally, a number of phlegmatizers and their combinations were found. Suitable for phlegmatization of gunpowder are: dibutyl phthalate, dioctyl phthalate, diethylhexyl phthalate, centralite No. 1, triethylene glycol dimethacrylate, oligoester acrylate.

With the appropriate input of these phlegmatizers or their pairs, optimal conditions for the state of the phlegmatizing layer and energy parameters of the powder can be provided.

The following components were used in the composition of gunpowder:

nitrocellulose (GOST V84-2373-87), nitroglycerin (GOST V84-2386-88), which serve as the energy base and provide mechanical strength of the powder elements.

Diphenylamine (GOST 194-80) in the composition of gunpowder is used as a stabilizer of chemical resistance. A decrease of less than 0.3 wt.% Sharply reduces the chemical resistance of the powder, and an increase of more than 0.7 wt.% Leads to a decrease in the energy characteristics of the powder.

Ethyl acetate (GOST 8981-78) and water in the composition of gunpowder play the role of technological additives.

The use of dibutyl phthalate (TU 6-05-5119-82), centralite No. 1 (TU 6-14-205-87), dioctyl phthalate (GOST 8728-88), diethylhexyl phthalate (GOST 8728-88), triethylene glycol dimethacrylate (TGM-3 ) (TU 6-16-2010-82), oligoester acrylate (TU 113-00-05761643-27-92), performing the role of phlegmatizers, provide the necessary combustion progression of powder elements. A decrease in phlegmatizers of less than 2.0 wt.% Leads to an increase in the pressure of powder gases in the channel of the barrel of the weapon, and an increase of more than 4.0 wt.% Increases the mass of the powder charge and reduces the speed of the bullet.

The main distinguishing features of the proposed spherical powder are new values of the depth of the phlegmatizing layer, the concentration of the phlegmatizer in the layer, the dependence of the heat of combustion of the powder on the diameter of the powder grain.

Table 1 shows the main physico-chemical and ballistic characteristics of the new gunpowder in comparison with the prototype for specific examples. Tests were carried out in cartridge 308 WIN with a bullet weighing 10.9 g. The content of the components within the limits stated in the claims is reflected in examples 2, 3, 4. The limit values of the amounts of the composition are given in examples 1 and 5.

Table 2 shows the main physico-chemical and ballistic characteristics of the claimed gunpowder in comparison with the analogue - gunpowder grade 2520 and the prototype - gunpowder SNF 30 / 3,69.

Table 3 shows the comparative parameters of the phlegmatization layer, the calorific value and ballistic characteristics of the claimed gunpowder and analogue in the automatic machine guns "Remington 223".

Table 4 shows the comparative parameters of the phlegmatization layer, calorific value and ballistic characteristics of the new gunpowder and the analogue in rifle cartridges "Winchester 308".

The table shows a significant difference between the new gunpowder and the prototype in terms of physico-chemical characteristics. By optimizing the combustion process, an increase in the speed of bullets, a decrease in the maximum pressure of the powder gases, and an improvement in stability in the group of shots are provided.

It should be noted that spherical phlegmatized gunpowder, the parameters of which will differ by 5 ... 10% from the proposed, will sharply worsen the quality of the cartridges.

Bibliographic data

1. V.M.Sabelnikov, V.M. Kirilov. "Cartridges of small arms", Moscow, 1979, p. 264.

2. “Accurate Smokeless Powder,” 1994, p. 346.

3. The industry standard (OST V84-2432-89) "Varnish powder". General specifications.

4. A.G. Gorst. “Gunpowder and explosives”, Oborongiz, 1949, p. 233.

Table 1 Composition Components Gunpowder options Prototype gunpowder, wt.% Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Nitroglycerine nine 12 14 fifteen eighteen 12 Ethyl acetate 0.5 0.3 0.4 0.7 0.4 0.5 Centrality No. 1 0 4 3 2 5 5 Dibutyl phthalate and / or 4.3 2 1,5 Dioctyl phthalate and / or 2 Diethylhexyl phthalate and / or 2 Oligoester acrylate and / or 4 Triethylene glycol dimethacrylate - - - 4 - - Dinitrotoluene - - - - - 2 Diphenylamine 0.8 0.7 0.7 0.7 0.2 0.8 Water 0.4 0.5 0.5 0.5 0.5 0.7 Nitrocellulose 82.0 78.5 77.4 77.1 72,4 79

Continuation of table 1 Ballistic specifications Mass of charge, g 3.0 2.85 2.82 2.82 2,52 2.65 bullet speed, V _25cp , m / s 772 823 819 821 802 785 Bullet speed spread, 36 12 fifteen eighteen 29th 28 ΔV _25, m / s Maximum pressure powder gases P _{m avg} , kgf / cm ² 3471 2934 2886 2902 3494 3248 Spread of maximum powder pressure gases, ΔР _m , kgf / cm ² 248 125 142 138 237 304

Table 3 Gunpowder mass Name of cartridge Phlegmatizing layer, microns The concentration of the phlegmatizer in the layer,% Calorific value, kcal / kg Mass of charge, g V cp / ΔV, m / s Rm Wed, kgf / cm ² Analogue 223Rem 180 eleven 870 1,56 915/27 3522 Claimed gunpowder 223Rem 35 eighteen 908 1,54 927/12 2904

Table 4 Gunpowder mass Name of cartridge Phlegmatizing layer, microns The concentration of the phlegmatizer in the layer Calorific value, kcal / kg Mass of charge, g V25cp / ΔV25, m / s Rm. Wed kgf / cm ² Analogue 308Vin 180 eleven 870 2.80 832/24 3500 Claimed gunpowder 308Vin thirty twenty 915 2.85 334/11 2874

Claims (1)

Spherical phlegmatized gunpowder for submachine gun and rifle cartridges, consisting of spheroidal powder grains with a phlegmatic surface layer, containing an energy base - nitrocellulose and nitroglycerin, ethyl acetate, phlegmatizer - Central No. 1, chemical stability stabilizer - diphenylamine and water, additionally characterized in that contains dibutyl phthalate and / or dioctyl phthalate and / or diethylhexyl phthalate and / or triethylene glycol dimethacrylate and / or oligoester acrylate as a phlegmatizer, the thickness of the phlegmatization surface layer has a value in microns: S = 55-0.0312D, where D is the diameter of the powder grains, microns, and the concentration of the phlegmatizer in the phlegmatization surface layer is 8-20 wt.%, the heat of combustion of the powder in kcal / kg corresponds to the formula : Q = 685 + 0.344 D in the following ratio of components, wt.%: ethyl acetate 0.3-0.7 central number 1 2.0-4.0 dibutyl phthalate and / or dioctyl phthalate and / or diethylhexyl phthalate and / or triethylene glycol dimethacrylate, and / or oligoester acrylate 2.0-4.0 diphenylamine 0.3-0.7 water 0.2-0.6 nitroglycerine 12.0-15.0 nitrocellulose rest.