Boron-containing cored wire is used to adjust the boron content, and the boron content set by Zhao Qingshan is 0.003~0.005%.

Although the content of boron is small, it plays an important role in 945 steel, and theoretically 0.003~0.005% boron can significantly improve the yield strength and hardenability of 945 steel.

Carbon, silicon, manganese, nickel, chromium, molybdenum, copper and other elements also assume various functions in order to ensure that the performance of 945 steel meets the standards.

Composition setting is one thing, but more important is smelting and rolling.

Zhao Qingshan: They have arranged the various elements clearly, but whether they can be smelted on industrial equipment is a test.

After the 945 steel furnace was refined, it was sent to the continuous casting workshop, and the continuous casting billet was late at night.

Liu Yahui yawned and was tired: "Ha...... Yawning, squatting from eight o'clock in the morning to the turning clock every day, I can't bear it. ”

Zhang Tongqiao said quite energetically: "I can carry it physically, but every day when I go back so late, my lover begins to doubt me." ”

Zhao Qingshan said: "Sister-in-law suspects Zhang Gong? Then you have to prove your innocence to your sister-in-law overnight when you go home." ”

Zhang Tongqiao was stunned, and then laughed: "The proof question has been done, and it has never been broken." ”

"I haven't seen you prove the child. Liu Yahui said.

Zhao Qingshan pretended not to hear, and said that Liu Yahui's emotional intelligence was too low.

Zhang Tongqiao has been married for four years, and he wants to have a child, but his lover has not conceived a child for a long time.

Although everyone knows about this, you can't poke his sore spot in front of Zhang Gong.

Zhang Tongqiao snorted coldly, his face gloomy.

"Okay, okay, don't go off-topic, let's measure the data. Liang Minfang is a mother of one child, and she also wants to go home early.

The billet of continuous casting is an ingot-shaped cuboid with a width of 700~1600 mm, a thickness of 170 mm, 210 mm and 250 mm, a length of 8~10 meters, a short length of 4~4.8 meters, and a single weight of 3.62~30.4 tons.

A billet is a semi-finished product of steel, which is rolled into finished steel such as plates, bars, and wire rods.

After testing by quality inspectors, the quality of 945 billets is qualified.

Engineers used photoelectric spark direct tester and carbon and sulfur analyzer for composition detection, carbon 0.12%, silicon 0.60%, manganese 1.10%, phosphorus 0.018%, sulfur 0.020%, nickel 1.20%, chromium 0.50%, molybdenum 0.08%, copper 0.15%, boron 0.002%......

Liu Yahui rubbed his hands and said, "The ingredient data is okay." ”

Zhao Qingshan shook his head and said: "Sulfur is high and boron is low, and 945 steel needs to be further improved in the smelting process." ”

Liang Minfang said: "High sulfur and low boron has always been a major issue to be solved, this furnace 945 steel to the continuous casting line, all aspects of the data as a whole meet expectations, tomorrow morning to report to the leader, and then hot rolling?"

"Okay, call it a day. ”

The four of them had a busy day, each going back to their respective homes.

The next morning, Zhao Qingshan, as a representative of the Iron and Steel Research Institute, reported to Ye Guoguo: "This furnace of 945 billets has been sent to the hot rolling mill, and in the smelting process of the second steelmaking, we have found several pros and cons. The good news is that our RH deep decarburization and dephosphorization are very powerful, and most of the alloying elements can be adjusted to the desired composition content in the initial refining and refining. ”

"Boron is chemically reactive, and precise control of boron content is not easy to achieve during RH refining. We add aluminum, zirconium and other alloys to fully deoxidize, add titanium alloy to fully fix nitrogen, and then add boron-containing core-clad wire to fine-tune the boron content, this process I think there is no problem, although it is not the best way, but there is no better way, it can be used. ”

Ye Guoguo looked at the data, and he asked: "Isn't it the best way to consume precious metals to ensure the yield of boron and other trace elements?

"I don't know, I just know that the method we use is the best method at the current level of technology. Zhao Qingshan replied, he continued: "The refining technology of boron and other trace elements is difficult to update in the short term, and we can only achieve the ultimate refinement in operation under the condition of existing technology." For example, the timing of adding precious metal alloys, the amount of material, etc., can be more refined in manual operation. It would be nice to increase the boron content by 1 to 2 parts per 100,000. Practice makes perfect, and I'm sure our on-site operators can do it. ”

"Actually, what is more troublesome than boron is sulfur, which is a harmful impurity in steel, and the more thoroughly desulfurization is done, the better. We want the sulfur in 945 steel to be controlled below 0.01%, and the sulfur in this furnace steel is 0.02%, and I am not satisfied. ”

"Not only 945 steel, but any kind of steel other than silicon steel, deep desulfurization has been a long-term technical problem. Ye Guoguo said, he added: "I also know that the solvent desulfurization method used by our RH is by no means the best method, and in the world, the best method of deep desulfurization is in the hands of Dongying and West Germans." Our 1.7 meters were bought from Dongying and West Germans, and they did give us some advanced technology, however, they kept their mouths shut about major technologies, including deep desulfurization, and did not even publish papers. ”

Zhao Qingshan nodded and said, "In a few years, we will enter the 90s, rely on yourself." ”

"What kind of whimsy does Xiao Zhao have?" Ye Guoli suddenly remembered that last summer, Zhao Qingshan said "rely on yourself", and then self-developed paint was born.

Zhao Qingshan said: "I have a little idea, let's make a few furnaces of 945 steel first." ”

"Okay, a few of you go to the hot rolling mill and continue to follow up on 945 steel. ”