Chapter 531 Armor
In American history, there was a soldier who had a weird temperament and a bad temper. He was called "the most stubborn bastard in the Navy" by his subordinates. He often insulted and ruthlessly threatened his colleagues and subordinates. Some people said that he "made life difficult for everyone around him", even his wife and children. Moreover, this guy was addicted to smoking and drinking, and he was also lustful and played with women. His private life was extremely dissolute, just like a gangster.
But such a bad guy became the greatest military all-rounder in the history of the US Navy! Whether it was submarines, cruisers, destroyers, battleships, aircraft carriers, or naval aviation, naval logistics and laboratory research, he could handle it. He even accompanied the president to do diplomacy all over the world. He was quite proficient.
This guy was one of the only four five-star admirals in the Navy in American history: Ernest Joseph King.
In his military career, Ernest scolded countless people and ruined a lot of people. His bad temper was annoying to everyone. But President Roosevelt recognized Ernest's talent and was determined and courageous! He promoted him to Vice Admiral in 1938 and recently appointed him as the commander of the North Atlantic Fleet.
"Four more patrol ships lost contact today."
The tonnage of this type of patrol ship is small, and even if it is hit by a torpedo, it will sink immediately, and there is basically no time to send a distress message. In addition, the maritime defense circle has been extended to 1,500 kilometers, and it is difficult to provide timely reinforcements. From the declaration of war on Germany to now, they have lost more than 20 ships, and all of them were sunk by the enemy's submarines.
"..." Roosevelt, who was furious about Cordell Hull's murder and wanted to declare war on the Soviet Union immediately, gradually calmed down. The United States has already caused a big trouble with Germany, and it cannot provoke another Soviet Union. "What do you think?" He secretly made up his mind that after solving Germany, he must make the Soviet Union pay a painful price!
Ernest took out a document. "This is the battle plan I have drawn up. We should take the initiative and teach the Germans a lesson."
In Berlin, Germany, Yannick came to Krupp to inspect the research progress of new armor.
Tank armor can be classified into many categories according to its properties, materials, manufacturing methods, composition, etc. High-quality rolled homogeneous steel armor (RHA) has become the mainstream product of tank armor in World War II with its dense structure, good anti-bullet and processing technology. RHA has become the standard for measuring armor anti-bullet.
Alloy steel armor is made by adding alloy elements such as nickel, chromium, molybdenum, and manganese to ordinary steel armor, which doubles the hardness and toughness of steel armor. Taking the famous nickel-chromium alloy steel armor in World War II as an example, by adding 2% to 6% nickel, 1% to 5% chromium, and 2% to 6% molybdenum to ordinary medium and low carbon steel, after special heat treatment process, it can be made into high-grade alloy steel armor that is hard and tough, hard on the outside and tough on the inside. Its yield strength reaches 720 to 900 Newtons per square millimeter, which is more than twice that of ordinary steel armor.
But for resource-scarce Germany in World War II, these are veritable "rare metals", and the quantity cannot even meet the needs of industrial production.
So Germany's traditional technological advantages played a huge role. The armor of the Tiger tank is very different from the nickel-chromium alloy steel armor of the United Kingdom, the United States and the Soviet Union. To be precise, the Tiger is not an alloy armor, but a steel armor containing trace amounts of manganese and molybdenum, generally called molybdenum steel armor.
Molybdenum can improve the ductility of steel and make it tougher. But there are very few molybdenum mines in Germany, only in Norway. Since the Norwegian molybdenum mine was bombed in the late World War II, the armor quality of German tanks has seriously declined.
In desperation, Germany can only use armor surface quenching carburizing hardening technology to make up for the shortcomings of the armor steel element structure.
Carburizing process is now commonly referred to as surface hardening process. Under normal circumstances, ordinary low-carbon steel plates that have been carburized and quenched can penetrate carbon elements at a depth of 8 to 2 mm on the surface. Some carburizing depths can reach 2 mm or even deeper. In theory, the deeper the better. The surface strength of low-carbon steel after carburizing and quenching is 20-30% higher than that of ordinary low-carbon steel plates, which can increase the thickness of armor.
However, its performance is not proportional to weight gain.
For example, if the same 20 mm steel plate is carburized steel, although the protection performance can be improved to about 26 mm, its weight is equivalent to that of a 33 mm thick steel plate. This is also an important reason why the weight of German tanks remained high in the late World War II. If the 56-ton Tiger tank is armored with nickel-chromium alloy steel, it can reduce its weight by at least 10 tons; its mobility will be significantly improved.
Another drawback of using surface carburizing hardened armor is that while the hardness of the armor is strengthened, its armor toughness is greatly reduced, in layman's terms, it becomes brittle! Especially in the late 1944s, many German tanks with declining armor technology were not penetrated by the firepower of the Allies but had large-scale armor cracks. Records show that the upper armor of a Tiger King was cracked after being hit by SU-152, but it was not penetrated, which is the reason.
In addition, the surface hardening process is also quite complicated. This is not a simple quenching. The so-called carburizing is to go through low-temperature tempering, primary heating quenching, high-temperature carburizing and tempering, secondary quenching and cold treatment on the surface of the formed steel plate, which is time-consuming and laborious. There are also requirements for steel. The steel plate used is a low-carbon steel plate (carbon content is less than 25%). If there is enough carbon, carburizing and quenching cannot be done.
Fortunately, this time Yannick explored and integrated the resources of various European countries. Although the rare resources are still rare, they can still meet the military needs of the German army. German armor has finally embarked on the road of alloy steel doped with rare metals such as nickel, chromium, and molybdenum.
However, Yannick is not satisfied with this. He continues to improve steel smelting technology. Through vacuum smelting, electroslag remelting, etc., the impurities such as sulfur and phosphorus in steel armor are reduced to less than 01%, and the bullet resistance of steel armor is further improved.
Under his guidance, the scientific research department has developed aluminum alloy armor and ceramic composite armor.
Comparing aluminum alloy and steel armor of the same weight, the effect of aluminum alloy against armor-piercing bullets is slightly worse, but the effect of anti-armor bullets is better than that of steel armor. In addition, the high rigidity of aluminum alloy can save structural parts such as reinforcing ribs and beams, thereby reducing the weight of the whole vehicle. Therefore, aluminum alloy armor is widely used as the main armor of light armored vehicles.
As for ceramic composite armor, its structure is similar to that of cream sandwich biscuits. The face plate layer is made of alloy steel with high hardness, the base plate layer is made of alloy steel with high toughness, and the middle layer is made of many small ceramic balls. The gaps between the balls are filled with glass fiber reinforced resin.
In this way, when a fierce armor-piercing projectile passes through the "sandwich" layer, the bullet has become blunt and consumed a lot of energy. Then, the tougher ceramic balls in the middle layer decompose and dissipate the main impact of the bullet. Finally, when the armor-piercing projectile that has lost most of its energy hits the high-toughness inner base plate, it no longer has any armor-piercing ability.