Chapter Five Hundred and Nine Brothers Factory Inspection
"Electroslag-replenishing steel technology is simply a major breakthrough in the manufacturing of tank gun barrel materials." When we arrived at the Second Machine Factory, Director Xie Huimin of the Second Machine Factory greeted them very affectionately and took them directly to the production factory.
Xie Huimin pointed to the equipment being produced and said.
At this time, you can clearly feel the heat waves attacking people. The steel ingots below are forming, and you can see the fiery red steel ingots, extremely dense and compact.
Since the ancient times, metal smelting began, the important part was how to extract impurities. When the temperature was not enough and the metal could not be melted, there was often a way to jump into the furnace by martyrdom and increase the furnace temperature. The commonly used knocking was also through this kind of tempering, which constantly knocked out the carbon in the steel, thereby improving its purity and increasing toughness.
With the development of technology to this day, there have been a series of progress, and the electroslag-repellent steel is a very good operation method.
This is a secondary refining technology. In a water-cooled crystallizer, the metal or alloy is remelted and refined by the resistive heat generated when the current passes through the slag. After melting, the high-purity molten steel goes downwards to form the required shape. Now, since the gun barrel is produced, the one that goes down is directly a dense round steel ingot, and the slag is floating at the upper end of the gradually condensed molten steel at this time.
"The steel remelted by electroslag has a very good quality, high purity, low sulfur content, few non-metallic inclusions, smooth surface of the steel ingot, clean, uniform and dense, and uniform metallographic structure and chemical composition. The casting mechanical properties of electroslag steel can reach or exceed the index of forgings of the same steel type." Xie Huimin said: "The steel ingots we cast are higher than the quality of forgings. Therefore, after the steel is smelted, it will directly enter the next process of manufacturing the gun barrel, and there is no need forging at all."
This is the first set in the country, which is used to produce the most needed tank gun barrels. Now, walking along the production line, you can see that the cylindrical ingots that have been melted through the electroslag are directly sent to the next machine. This is a large drilling machine equipped with an extra-long drill bit. After the gun barrel is fixed, a hole will be drilled inside while it is still hot.
This is not simple, it is a "deep hole processing" that is very difficult to process. The drill bit is six or seven meters long. As it continues to drill in, deviations may occur at any time. As long as there is a slight deviation, the drill hole will be scrapped and the entire barrel will be scrapped.
Especially, since the drill bit cannot see the processing surface, the operator cannot see it directly and can only operate based on experience.
"The masters of our Second Machinery Factory are also experienced." Qin Zhenhua sighed.
After drilling, the body tube tightened immediately. This technology was also introduced from abroad.
The body tube was tightened, and it took a long time to go through. The earliest one was the British naval gun. A circle of dense steel wire was wrapped outside to increase the strength of the barrel. Later, multiple layers of gun barrels appeared. As for the modern body tube tightening process, it started with the British L7 rifled gun.
In terms of principle, it is not complicated. In fact, it is to stuff a conical device behind the hole that has been drilled. The largest circle behind is higher than the inner diameter of the drilled. Then, use a hydraulic press to squeeze the conical device into it, that is, stuffing this object thicker than the steel pipe into it, expanding the inner chamber without changing the outer diameter. During this squeezing process, the inner chamber of the gun barrel is squeezed tighter and denser.
It's simple to say but difficult to do.
It has been studied in China for many years, but no results have been published. It has not been truly available until now.
This is the principle of self-tightening of the body tube. Then, a series of operations such as rifling, chrome plating, etc. can be determined after inspection and measurement.
"Now, the production line is still in the trial operation stage, and our monthly output is only about a dozen." Xie Huimin said: "So, our first-machine factory has been urging us to build the gun barrel and install it, but we can't pull the seedlings to help grow. This process can be familiar with it slowly."
After saying that, Xie Huimin continued: "Moreover, we are not only building guns, but this set of equipment also plays a greater role. Our future tank guns also need to be produced on this set of devices."
After saying that, Xie Huimin looked at Qin Zhenhua: "Assistant Qin, you are too busy with work. Our 120mm tank gun experiment is still waiting for your progress."
Don't urge us, you urge us, we still want to urge you.
Hearing this, Qin Zhenhua apologized: "Yes, our first-machine factory is moving too slowly, but please rest assured that our scientific research projects are accelerating. Both the 1224 tank and the Storm 2 tank can be equipped with 120mm tank guns."
Now the first machine factory has developed the 1223 tank and the Storm 1 tank. These two tanks are equipped with 105mm tank guns. The 1223 tank is the first model of the second-generation tank. When it was designed, it was planned to directly buckle the existing cast turret, so it is impossible to stuff the 120mm tank gun into it.
As for the Storm 1 tank, if you want to sell it as soon as possible after it is manufactured, it is impossible to install the 120mm tank gun that is still under development. It is more suitable for a mature and reliable 105mm tank gun.
Now, 120mm tank guns and 125mm tank guns need to compete to see which one is more suitable. The 125mm shell has begun to be tested and has mastered more technical information. The tank gun with only 120mm has not started loading. Xie Huimin is a little anxious.
"Your machine factory has too many R&D projects." Xie Huimin said: "It won't be chewed too much, so if you can't afford some other projects, if you machine factory can't afford it, you can also give us some second machine factory some and let us help share it."
Qin Zhenhua smiled and looked at Xie Huimin: "Director Xie, are you talking about the upgrade of the 59 tank?"
I had this kind of premonition. This time I came here, I was just asking for information. Now, the other party has confessed.
"Yes, the army is planning to upgrade tank guns for the 59 tank. For such a small job, there is no need to bother you, the first aircraft factory. Our second aircraft factory can steadily replace the gun barrel." Xie Huimin said: "After all, your first aircraft factory is also doing big business and doesn't look down on this little job."