The Soviet armored steel was actually a history of introduction. Russia's industry was underdeveloped during the Tsarist era, and the quality of armored steel was not good (as can be seen from the poor performance of Russian warships during the Russo-Japanese War) and it was very dependent on imports (Germany, France, and Britain). It was not until the 1930s that when the Soviet Union began to vigorously develop armored forces, it began to systematically sort out the metallurgical industry.

For example, the steel of the BT series tank is a fully introduced American technology. It was not until the T-34 era that the Soviet armored steel basically kept up with the world's advanced pace (it was still slightly worse). For example, the steel used by the T-34 is chromium manganese nickel chromium molybdenum homogeneous steel (the 7d and 8s series). The performance of these two armored steels is naturally advanced compared with the Tsar era, but compared with the world's most advanced level, it still seems to be insufficient, for example, the steel is not very tough.

Now, t-34, t-35 and even t-54 all use 7d and 8s series steel. Take t-54 for example. The current t-54 has a considerable gap in defense compared with the historical t-54, and the main reason for this gap is the problem of steel. The historical t-54 uses more advanced 74d armored steel, which exceeds the 7d series several streets. In other words, the current t-54 is actually a shrinking version, which is incomparable to the original genuine licensed products.

Now, Li Xiaofeng demanded to increase the defense of T-35, but he could not make large structural adjustments. The only way is to use better armored steel. So does the Soviet Union have better armored steel now?

Unfortunately, it has not been there yet. Although the Northern Industrial Metallurgical Laboratory has been improving the armored steel process, there has not made much progress in a short period of time. Anyway, at least it is impossible to quickly produce the 74d series of steel.

It seems that this path cannot be done either? Constantine soon put forward another new suggestion: "The only way is to use carburized armored steel!"

The so-called carburizing armored steel is to increase the hardness of the surface layer of the steel through the surface carburizing process. As we all know, armor-piercing bombs are head-on. If the hardness of the steel exceeds the hardness of the core, the latter's armor-piercing ability will be weakened, or even directly broken.

This process is actually not unusual at all. It has been born for more than 40 years and began in the late 19th century. It was first invented by American engineer Harvey, and then the German Krupp Company promoted it and was widely used in armored steel for ships.

In fact, the Germans also used carburizing technology on the steel of tanks, and generally speaking, their surface hardness was greater than that of other countries. If the Soviet Union also built a surface carburizing armored steel for tanks, it seemed like a good solution to insufficient defense?

However, this proposal was firmly resisted by Li Xiaofeng: "Surface carburized armored steel has no future, and it is a waste of time and cannot be used!"

Why does a fairy say that? This has to start with the surface carburizing process. First, you have to make qualified steel and roll it into sheets, and then place these sheets in a gas or liquid carburizing chamber for carburizing. This carburizing process takes a lot of time and it is difficult to penetrate one or two millimeters of steel in a few hours. It takes a lot of time to obtain qualified surface carburizing steel!

Now, the Soviet Union did not have so much time to waste. Instead of being so "scrutinized", it is better to produce a few more tanks to make. What's more, the surface carburizing process is very technical. The carburizing layer should not be too thick. If it is too thick, it will affect the overall toughness of the steel. It will collapse and crack under the attack of high-speed armor-piercing bombs, which will reduce its defense. At the same time, the carburizing layer should not be too thin. If it is too thin, it will not work. This process takes into account the experience and level of the technician, and it will not be careless at all!

Why did Germany produce so many tanks in World War II than the Soviet Union? It was not only because the Germans liked to develop fancy and complex and unqualified technologies. Carbonized steel consumes time.

Of course, this is not the most important reason why Li Xiaofeng opposed the use of carburized armored steel. More importantly, he knew that this thing had no future. With the birth and widespread use of the AP (capped armor-piercing projectile), the APB (truncated armor-piercing projectile), the APB (hollow closure armor-piercing projectile), and especially the APR (sub-caliber speeding armor-piercing projectile), the death penalty for carburized armor was completely sentenced.

Take the apr as an example. Relying on the initial velocity of up to 1,200 meters per second and the tungsten carbide bullet core, the time-consuming carburized armor is as fragile as a piece of paper. Not only the apr, but also for homogeneous armor. The hollow armor-piercing bomb is ignored regardless of whether you have carbon leakage or not. Li Xiaofeng does not want the carburized armor that was made at a huge cost to be declared dead in less than two years. That is a huge waste.

It seemed like there was no way out, but in desperation, a certain immortal could only continue to cheat. Others did not know the formula and crafts of homogeneous steel armor in later generations. He could get it from the treasure pot with some immortal power. The only thing that made him hesitate was which one to choose.

Yes, there are two options in front of Li Xiaofeng. One is the copycat r-touch steel (ai private 4130) and its improved version of 4340 steel made by the US imperialists during World War II. This 4340 steel is not ordinary. It has been used from the m41 tank to m60, and it is still used on m1a2.

Anyway, if 4340 steel was created, it seems that the Soviet metallurgical department could have been on the verge of more than ten years. However, Li Xiaofeng was a little hesitant because he felt that 4340 might not be in line with the national conditions of the Soviet Union, not to mention that the Soviet armored steel during the Cold War did not have to be inferior to the United States (or even stronger). For example, the 75d armored steel developed from 74d is an armored steel with excellent comprehensive performance, with a hardness of hb262-311 (the hardness of the German World War II armored steel substrate was hb0-240), and the hardenability of the steel was quite superior (up to 350 mm). The superior performance of 75d armored steel has long been ahead of the West, and it was still in use until the T-90 tank.

The Soviet Union not only had 75d but also had higher hardness 52s armored steel, with a hardness of up to hb285-341 and its hardenability can also reach 120 mm. The 53s developed from 52s ensures hardness while increasing the hardenability to 150 mm. It is mainly used in the car head armor (75d is generally used in turrets because of better casting).

After thinking about it, Li Xiaofeng finally decided to copy himself, first make 74d armored steel, and then make 75d and 52s. When someone handed over the technical information and some of the physical objects of 74d armored steel to Constantine, the pseudo-woman was furious: "With such good steel, why didn't you say it earlier!"

Li Xiaofeng was speechless, why did he say this earlier? How could he expect Tukhachevsky to spend almost the advantage he had accumulated after finally accumulating. If he had known this before, Tukhachevsky would have done it directly in the 1930s, and where would this bastard have turned to ruin his big thing!

Fortunately, Constantine did not pursue this problem, and this technical pseudo-woman was completely attracted by the new technology and wanted to start working immediately.

Li Xiaofeng quickly grabbed him: "By changing armored steel, do you think the bulletproof ability of t-35 can meet the requirements?"

Cons Dante calculated it and shook his head and said, "According to my estimate, if the armor thickness is not increased, it is just by replacing new armor. The turret defense of the t-35 is equivalent to 80 mm level, and the front of the car is about 60 mm level!"

Li Xiaofeng frowned and said, "This is not enough!"

Yes. A certain immortal's ambition has risen again. He thought 80mm was acceptable before, but now he is ready to follow one hundredmm!

"If you want to reach the equivalent level of 100 mm, the t-35's turret armor must be increased from the current 45 mm to 70 mm." Constantine replied after an estimate.

The 70mm turret is not as exaggerated as 90mm, and it can be done with just a little strengthening of the first pair of torsion rod suspension. Of course, the turret must be replaced, and there is no way to do it, but the 70mm thick turret must be lower than the 90mm process requirements.

However, Li Xiaofeng is still not satisfied. The level of 100 mm is possible to deal with the kk40 tank gun, but it is probably not enough to deal with the pak40. As for the kk36 and kk43, there is no need to think about it, especially the latter, which can only be withstand the genuine T-54.

So Li Xiaofeng felt that he had to follow the kk36. It would be better to make the t-35 reach the equivalent level of 120 mm homogeneous armor. However, it is difficult to achieve this, at least in Constantine's opinion: "Then it takes 100 mm thick on the front of the turret! This thickness is a huge burden on the body!"

Li Xiaofeng's idea was different because he was different from Constantine. Constantine did not know the future development direction of tank armor, but he knew that it seemed that he could test the composite armor at this time.

Of course, Li Xiaofeng did not think of reaching the sky in one step. The composite armor of ceramic interlayers cannot be handled under current technical conditions. He planned to start with a simple one. For example, first installing the composite armor of gap armor or phenolic resin interlayers.

For example, we can refer to the experience of the Soviet Union in t-64 to reserve a mezzanine in the cast turret. After the turret cools, we will fill the mezzanine with refractory rubber or phenolic resin. This idea was a big idea in the eyes of the technicians at that time. According to their ideas, homogeneous armor without mezzanine should be better blastproof. If a mezzanine is opened in a whole piece of armor, does not this reduce the overall strength of the armor?

However, Li Xiaofeng was the boss after all, and he set a goal, so people on this side could only start experimenting. Soon the metallurgy laboratory of Northern Industry began to use the existing 7d and 8s series armored steel for interlayer testing.

That is to say, two 40mm thick 7d and 8s armors were sandwiched with a phenolic resin sandwich, and then fired. Through intuitive comparison tests, the effectiveness of the composite armor was examined. This test never stopped as soon as it was carried out. In just three months, the metallurgical laboratory conducted more than one hundred comparison tests, and the entire test site could be said to be sounding guns.

Through comparative tests, the Northern Industrial Metallurgical Laboratory found that even without using more advanced 74d armored steel, just using 7d armored steel and interlayer can achieve good results. For example, the new armor composed of 40mm 7d steel + refractory rubber + 20mm 7d steel + refractory rubber + 20mm 7d steel is much stronger than the pure 80mm 7d steel, and its bulletproof ability can be improved by about 20%. If the refractory rubber in the interlayer is replaced with phenolic resin or alumina ceramic material, the bulletproof performance will be further improved.

This result made the northern industry very excited. They discovered a new way to improve their defense. However, when they were about to use their hands and feet to install simple composite armor for the T-35 and T-54, they were denied by Li Xiaofeng.

It’s not that Li Xiaofeng goes back on his word, but that the reality does not allow it. According to the research of the Northern Industrial Metallurgical Laboratory, it is best to use welding rather than casting. This creates a problem. The welding process is complex and takes more time than the casting process, which does not meet Li Xiaofeng’s requirements. For the Red Army, quantity is very important!

In particular, it takes time to get the new armored steel. It also takes time to solve the welding process problem, and the manufacturing of composite armor takes time, so naturally it cannot afford to be injured. Therefore, the first attempt of composite armor in the Soviet Union was rejected, but Li Xiaofeng did not completely deny the achievements of the Metallurgical Laboratory and still invested a lot of funds to allow them to continue their research. After all, if composite armor is not used for the time being, it does not mean that it will not be used in the future.

This also directly caused the first phase of the T-35 transformation plan to involve only two aspects. The first is to replace the new armor, and the other is to strengthen the thickness of the armor according to your ability. In June 1942, the T-35 turret armor that caught up with the second Kiev defense battle increased to 80 mm, and the car's head armor increased to 50 mm. Including the inclination angle, it can basically be immune to the attack of kk40 at a distance of more than one thousand meters. At the same time, the 100mm smoothbore cannon can also knock on the black panther's turtle shell. Compared with the T-34-76 that was abused by the black panther at the same time, the survivability of the t-35 is more than a little bit higher.

Just as Li Xiaofeng tried every means to solve the problem of weapon capacity, the first tragic battle to defend Kiev finally started. Longdested's first tank group rushed to the front, and the 6th and 17th Army followed closely and arrived at the city of Kiev very easily.

At this time, Shaposhnikov and Temushingo were in a state of great difficulty in the city of Kiev because they had too few troops, except for the 12 temporary militia divisions. The only troops in Kiev that could fight were only 10 divisions. Among them, in addition to the five infantry divisions originally stationed in Kiev, the Caucasian Front reinforced two infantry divisions and two infantry brigades. They fled back in a panic under the German encirclement, with a total of about ten divisions. In addition, there were about five reinforcements on the Central Front Army, and there were almost no more troops.

Anyway, Shaposhnikov didn't know how to fight this battle. He only had 25 divisions of troops, and on his front, there were about 60 divisions of the German Southern Army Group and Hungary and Romanian Servants. No matter how he looked, he had no way to survive!

"The order of the Military Commission is to let us hold on the spot and never take a step back. We will fight a street battle with the enemy around the surrounding areas of Kiev!"

Shaposhnikov pointed and explained his tactics and troop configuration: "The militia division was mainly stationed in the urban area. While other regular troops were responsible for the periphery of Kiev, I knew that the troops were not strong enough. So please try to shrink the defense line, and it is best to rely on solid fortifications to slowly deal with the enemy. Among them, the key points of defense are that the airport must be safe, and the second is to maintain the safety of the railway line from Kiev to Moscow as much as possible, otherwise we will not expect any reinforcements..."

Saying a thousand words, Shaposhnikov is still pessimistic about the future, because the enemy is too strong and the reinforcements are almost zero. When he thinks that when Kiev is in danger, Tukhachevsky is still carrying out "rescue" operations, he is full of anger.

Just when Shaposhnikov was most angry, Deputy Chief of Staff Triandafilov rushed to Kiev. As a special envoy of the Military Commission, he would supervise the Ukrainian Front to defend the great Kievan Rus.

"I'm not here to make trouble," Triandafilov said openly, "I was driven to Kiev by the Military Commission. We are the same sympathy!"

Why did Triandafilov say that? It's very simple. In the previous discussions between the Military Commission and the General Staff, he fully supported Li Xiaofeng, and had quite an objection to Tukhachevsky's approach, or simply said it was a strong opposition. At one time, his relationship with Tukhachevsky was extremely tense.

In order to let Tukhachevsky relax his hands and feet to carry out the "rescue" operation, the "disgusting" Triandafilov was "driven away" and temporarily turned him, the deputy chief of staff, into a supervising team member and threw him to Kiev.

"The 3rd and 10th Army really have no hope?" Although Shaposhnikov was dissatisfied with Tukhachevsky, he still hoped to turn the situation around. At the moment, Triandafirov's attitude almost said that there was no hope at all, which immediately made him feel cold.

"No!" Triandafilov replied distressedly, "I can't find any chance of winning through wargame deductions. Instead, such reckless actions will make more troops fall into trouble, and it is very likely that it will be another major defeat. Comrade Shaposhnikov, you'd better be prepared for the worst!"

Shaposhnikov naturally knew what the worst mental preparation was. Once Tukhachevsky was in trouble, it would be even more impossible for Kiev to obtain reinforcements. At that time, more troops would be used to block the gap in the direction of Minsk. This means that he would be able to deal with the enemy with the poor Bala's troops for a long time in the future.

However, Triandafilov was not blindly slandering. Instead, he was still encouraging Shaposhnikov: "Compared with the situation of the Third and Tenth Army, I think the direction of Kiev is not that dangerous!"

Shaposhnikov and Temuxin were both stunned. Now, if you want soldiers, no one, you still want them, you still want them to be called unintentional?

Triandafilov shook his head and explained: "Compared with the 3rd and 10th Army, our air power in the Kiev region is stronger, and air supremacy is firmly in our hands. If used properly, it will cause huge damage to the enemy!"

Shaboshnikov's eyes lit up immediately. He remembered the complaints of the front-line troops before. Under the city of Warsaw, the Luftwaffe abused them into dogs. Now, under the city of Kiev, is it the Red Air Force's turn to fight against German dogs? (To be continued)

ps: Bow to thank the foxes and plane wanted comrades in the desert!
Chapter completed!