armor protection is the basic feature of the tank. Before the emergence of reactive armor and active protection technology, the protection of tanks was mainly provided by the armor of the hull and turret itself. The armor structure of the tank turret has undergone the development process of riveting-casting, welding-welding. The main structural forms of modern tank turrets are casting and welding. Next, we will briefly analyze the characteristics of these two structural methods. The
tank was born in the First World War. The armor thickness of early tanks was mostly about 6-30 mm, and the main form of riveting was adopted. For example, the first French Renault FT-17 tank equipped with a rotating turret. The turret and the hull were riveted by homogeneous armor plates, with a small inclination of armor and a thickness of only 6 to 16 mm. When tanks first appeared, there were no specially developed anti-tank weapons. The armies of various countries mainly relied on ground-pressed artillery to conduct anti-tank operations. The muzzle velocity of the artillery was low and the power was not high; the tank manufacturing technology was not high enough, and the manufacturing was convenient and the thickness was not large. The armor can meet the requirements. Z1z
casting turret
After World War I, with the development of tank power and materials, the technical level of tanks has been greatly improved. The armies of various countries began to use a large number of anti-tank guns and tanks for anti-tank operations. The calibers of tank guns and anti-tank guns began to gradually increase, from 20 mm, 37 mm, 45 mm, and 47 mm to 50 mm, 57 mm and even 76.2 mm (such as the Soviet T-28 and T-35 heavy tanks), using armor-piercing ammunition specifically for anti-tank, even the infantry is also heavily equipped with 13.2 and 14.5 mm anti-tank guns.
Due to the rapid increase in the power of anti-tank weapons, the armor thickness of tanks also needs to continue to increase. Large-thickness armor is difficult to use in the form of riveting, but it is easy to achieve by casting and welding. So before the start of World War II, some tanks began to use cast armor, and began to form two different turret structures, casting and welding. For example, the famous T-34 tank, the turret is integrally cast, and the car body is welded with homogeneous armor plates; the German III, IV, and V tanks use welded turrets; the American M3A1, M4 and French S-35 The turret of the tank and part of the hull components are all cast. During World War II, the power of anti-tank weapons and the armor protection of tanks have been greatly improved. Taking Soviet tanks as an example, the front armor thickness of the T-34/85 tank turret reached 90 mm, and the IS-2 heavy tank reached 102. Mm. It can be said that in World War II, except for Germany, which admired precision machinery, cast turrets have been widely adopted by the Soviet Union and the United States.
Before the emergence of the stabilized tail wing armor-piercing projectile, ordinary armor-piercing projectiles were the main anti-tank projectile. Ordinary armor-piercing bullets can be divided into pointed armor-piercing bullets, blunt-headed armor-piercing bullets and cap-piercing bullets. The pointed armor-piercing projectile has a sharper head, and the impact force is concentrated when it hits the armor plate. It is easy to pierce and perforate the armor. It is suitable for shooting softer uniform armor. The projectile head is easy to shoot at a harder or hardened armor plate. It is broken and easy to jump when hitting the inclined armor with a certain angle. The head of the blunt-headed armor-piercing projectile is flat and blunt, and the contact surface is larger when hitting the armor. The reaction force per unit area of the projectile head is smaller than that of the pointed-headed armor-piercing projectile, which can reduce the damage of the projectile's head. It is not easy to jump when shooting an inclined armor plate. Fly, suitable for shooting harder armor. The capped armor-piercing projectile is welded with a tougher and blunt quilt on the outside of the sharper head to reduce flying. While the cap hits the armor and breaks, it also causes certain damage to the armor surface. Conducive to the continued penetration of the complete pointed projectile. In the case of ordinary armor-piercing projectiles and early shelling armor-piercing projectiles, a good protective appearance is an important factor for tank armor protection. In terms of overall performance, cast turrets have certain advantages over welded turrets. After World War II, most of the first and second generation tanks designed by countries around the world used welded hulls and cast turrets, such as Soviet T-54, T-55, T-62, British "Chiefs", French AMX-30, and Japan Type 61, 74 and German Leopard 1 tanks; Chinese 59, 69, 88B series tanks also use cast turrets. The hulls and turrets of the American M47, M48, and M60 tanks continue the manufacturing method of the M4 tank, and all use casting. The
cast turrets are all integrally cast, making it easier to produce. Simply put, it is to make a mold according to the shape of the turret in advance, pour the hot molten steel from the steelmaking furnace into the mold, and perform some necessary after cooling.After trimming, the casting of the turret is completed. The armor of each part of the
cast turret has a smooth transition. The thickness and angle of inclination of each part of the turret are properly configured, which can form a good protective appearance, and improve the bullet resistance of the armor through shape protection. The armor has a certain inclination angle, which not only makes the ordinary armor-piercing projectile easy to jump, but also increases the distance the projectile passes through the armor. While the welded turret adopts the same inclination angle as the cast turret, the structural weight of the armor is higher than that of the cast turret.
has an advantage over welded turrets in terms of bulletproof appearance, which is especially effective for protecting ordinary armor-piercing projectiles. The cast turrets all had a good bullet-proof appearance, and the protective ability of Soviet tanks was stronger than that of American tanks at that time. In addition, the armor utilization rate of the cast turret is high. Under the condition of reaching the same armor thickness, the weight of the cast turret is lighter than the welded turret. However, the density of cast armor steel is lower than that of rolled armor steel, that is to say, for armor plates of the same thickness, the ballistic resistance of cast armor is worse than that of rolled armor. It is generally believed that the ballistic resistance of cast armor of the same thickness of armor plate is 90% of that of rolled armor plate, that is, the ballistic resistance of 100 mm cast armor plate is approximately equivalent to 90 mm rolled armor plate. Moreover, casting armor has high requirements on the quality of casting. The defects such as blisters, pores and sand inclusions formed during the casting process will seriously affect the protective ability of the armor. At the same time, the requirements for heat treatment of cast armor are also very strict. The Soviet tanks produced during World War II, because of poor production sites and equipment conditions, and simplified production processes to increase production, produced tanks with more internal defects in the cast turret, and theoretically, the armor that cannot be penetrated by armor-piercing projectiles. It is often penetrated in battle.
welded turret
After World War II, because ordinary armor-piercing projectiles were difficult to penetrate the armor of the tank at that time, various countries stepped up the development of new-type armor-piercing projectiles, and successively developed rotating stable overspeed shelling armor-piercing projectiles and tail stabilized shelling armor-piercing projectiles. In order to maintain the rotational stability of the projectile, the length-to-diameter ratio (the ratio of length to diameter) of the core of the ordinary armor-piercing projectile and the rotating stable overspeed shelling armor-piercing projectile cannot exceed 4 to 5, and the improvement of armor-piercing ability is limited; while the tail wing is stable The length-to-diameter ratio of the armor-piercing projectile can reach 13 to 15 or more (currently more than 30), and the muzzle velocity generally reaches 1500 to 1800 m/s. It is not easy to jump at an angle of less than 65 degrees, and has a clear direction to the normal of the armor plate. The phenomenon of normalization uses high-density materials such as tungsten alloy and depleted uranium as the core material. The kinetic energy in the unit cross-sectional area of the projectile is large, and the armor-piercing ability is rapidly improved. At present, tungsten alloy armor-piercing projectiles can reach a vertical thickness of 600 to 700 millimeters at a distance of 2000 meters, and depleted uranium armor-piercing projectiles can achieve greater thickness. The armor thickness and inclination angle of the cast turret can no longer withstand the attack of the stabilized tail wing armor-piercing projectile. The shattered armor projectile is particularly suitable for shooting inclined armored targets at a longer distance, and can produce fragments on the inner surface of the uniform armor. Due to improvements in charges, fuzes, charge-type shields, partitions, and the appearance of tandem warheads, the armor-piercing capability of armor-piercing projectiles has also been greatly improved. The thickness of armor-piercing ammunition has increased from about 2 times the caliber during World War II to 6 times the caliber. the above.
tail stabilized shelling armor-piercing projectiles, the emergence of fragmented armor-piercing projectiles, and the greatly improved armor-piercing ability of the armor-piercing projectiles have made it difficult for simple homogeneous armor to meet the protection requirements, and the protective effect of cast armor is becoming less and less obvious. So countries have begun to develop composite armor and apply it to tanks. Composite armor can be divided into two types: metal composite armor, metal and non-metal composite armor, the number of layers varies from two layers to multiple layers, usually the outer layer is a metal material with high hardness and low toughness, and the inner layer is a metal material with low strength and high toughness. , If you use non-metallic materials, sandwich it in the middle. Because each part of the cast turret is curved and integrally formed, the shape of the internal space of the sandwich is complicated, which limits the structure and type of materials in the composite sandwich. After the emergence of composite armor, the tank turret appeared in the form of casting and welding coexistence, mainly welding structure. For example, the Soviet T-64, T-72, and T-80 tanks still use cast turrets, while the American M1 series tanks and the German Leopard "2 Tanks etc. use welded turrets.
German "Leopard" 2 main battle tank
welded turret is composed of multiple homogeneous armor plates (or castings) welded together, the process is more complicated than casting turrets. The production of welded turrets requires large-scale equipment to complete the rolling and forming of armor plates, and tooling is required to complete positioning during the assembly welding process.A large number of skilled welding personnel and welding equipment are required. The assembly welding of armor plates with large differences in the thickness of each part of the welding turret also requires special equipment and skilled technical workers to complete the processing. Therefore, the production cycle of welded turrets is generally longer than that of cast turrets. The rolled armor plate used in the welding turret will not have problems such as sand holes, pores and sand inclusions, and the protection ability is stable and consistent. However, if it is not handled well in production or there are welding defects, the welding seam of the welding turret will be a weak point. When the passive armor-piercing projectile hits in combat, even if the armor is not penetrated, the welding seam may crack. The
welded turret has a large internal space and a regular interlayer space, which is conducive to the use of a more complex composite structure, and the combination of different materials in different forms can improve the armor resistance. Therefore, in the case of using composite armor, welded turrets have greater advantages over cast turrets, and most of the newly developed tanks in various countries use welded turrets. Of course, this does not mean that composite armor cannot be used for cast turrets. The cast turrets of the Soviet T-64, T-72, and T-80 tanks used composite armor of metal and non-metal materials. According to information, the composite armor of the T-72 tank has a three-layer structure, the inner and outer layers are armored steel plates, and the middle is a multilayer ceramic and metal sandwich. In the early days of the tanks with composite armor, due to the lack of composite material technology, the welding turret was not superior to the cast turret in terms of protection level. The protection level of the turrets of the American M1 and early German Leopard 2 tanks was not as good as that of the period. Turret protection of Soviet T-72 and T-80 tanks. However, because the armor with a welded structure is thicker than the interlayer between the cast armor, and the interlayer space is relatively regular, more complex composite material structures and more high-performance materials can be used. With the improvement of the performance of metal and non-metal composite materials, the advantages of welding turrets in protection have been reflected. After the US M1A1HA tank with depleted uranium armor and the German Leopard 2A4 tank were installed, their armor protection capabilities began to surpass that of Soviet tanks, and the armor protection capabilities of tanks with welded turrets had room for further improvement, and it was easy to adopt modules Armored components. It is difficult for composite armors with cast structures to achieve further development in protection. Russia has now begun to study welded turrets and overhead artillery tanks. Compared with the welded turret, the
cast turret has the advantages of simple production process and complete structure, and the welded turret has higher protection capacity than the cast turret when using composite armor. Therefore, in addition to the two main turret structures of cast turrets currently used in the Russian T series and welded turrets used in the United States and Europe, there is also a turret with a mixed structure of casting and welding, that is, the basic structure of the turret is in the form of casting (called the base body). Or basic armor), give full play to the advantages of the integral casting structure, and at the same time adopt a composite armor module with a welded structure on the main bullet surface (this composite armor module is different from the structure composed of the fixed panel and the modular sandwich on the M1). The face, back plate and composite interlayer are combined into a whole armor module assembly). The composite armor module can be replaced, which facilitates the use of newly developed composite armor to continuously improve the armor protection capability, and also facilitates the replacement of damaged armor modules to repair battle-wounded tanks as soon as possible. In this way, the casting and welding structures can complement each other's strengths and form a new structure that is better than simple casting or welding turrets as a whole.
The development trend of tank turret structure in our country is basically the same as that of other countries in the world. The first and second generation tanks in our country use the same cast turret as the mainstream foreign tanks of the first and second generations. Composite armor.
It can be said that there is no question of who is more advanced than the cast turret and the welded turret. They are all developed based on the development of tactics and technology. From the perspective of the development of tanks in various countries after World War II, during the period when armored steel was used as the main protection method, cast turrets were a structural form commonly used in various countries. After the emergence of composite armor, a situation of casting and welding coexisted. The performance of the welded turret structure is better. Whether cast turrets, welded turrets or mixed-structure turrets, the protection of tanks can be further improved by using reactive armor and active protection technology. According to the development of tank technology, with the development of active protection technology and new tank weapons, unmanned turrets or overhead artillery tanks will appear. The current meaning of tank turrets may become history, and tank armor protection will enter a new Period.
