Lin Gao Qiming

Chapter 1315
Ji Wusheng has been watching the blast furnace, without saying a word from the beginning to the end, this time he decided to let the naturalized migrant workers follow the process by themselves - the specific smelting process has been discussed and drilled many times with the workers in charge of the trial, so Various accident situations that may occur have been planned.For this trial, he wanted to see if a naturalized migrant worker like Zhao Youcai could roughly complete the entire work process without the guidance and assistance of the elders.

Now the two blast furnaces and one open hearth furnace are equipped with Guihuamin's foreman according to the shift, but their work cannot completely reassure Ji Wusheng. Every time he taps iron and slag or adjusts the composition, he will come over to have a look and give advice. a bit.This time he wanted to see if the best furnace chief under his command could completely break away from the guidance of the elders.

Seeing that Zhao Youcai was looking at him, he nodded and said loudly, "Zhao Youcai, now you are in charge!"

A look of nervousness and excitement flashed across Zhao Youcai's face, and he responded loudly: "Understood!" Turning around, he began to direct the workers in front of the furnace to take their positions, waiting for the time to formally load the materials.He himself stared closely at the flames in the blast furnace,

"Start feeding for the first time!" Zhao Youcai suddenly shouted.The feeding workers on standby start the equipment and put a batch of materials into the blast furnace.

炼硅铁的料是按照硅砂、焦炭、生铁、生石灰四种原料5:3:1:2.5的比例混合的，因为是第一批投料，焦炭的比例比较高。到第5批料投过之后焦炭的投入比例可以逐步递减。

After adding the material, Ji Wusheng quietly left the observation platform - the first ironing will be in 3 hours, and he plans to come back at that time to see the actual ironing situation.

Three hours later, Ji Wusheng returned to the special blast furnace.The workers are nervously preparing for the first tapping of molten iron.Ji Wusheng checked the main ditch and the lower slag ditch for foreign matter without saying a word—this was the first time the special blast furnace tapped iron. In theory, there should be nothing in the two ditches. However, accidents often happen Things that "should have" didn't happen according to common sense.

Rubbish was mixed into the iron slag tank that should have no foreign matter at some point. As soon as the hot iron slag entered the tank, it was exploded like shrapnel, and two-thirds of the people in a blast furnace working class were wiped out in an instant. .

There have been more than one incidents in which major accidents have been caused by tapping iron without being ready for tapping.

According to the standard working procedures, Ji Wusheng personally inspected every link: whether the mud sleeve of the tap hole is intact, whether the diverter gates of the iron ditch and the lower slag ditch have been put down, whether the nozzle of the slag iron ditch is intact...

"I've already sent someone to send the melting sample to the laboratory." Zhao Youcai was busy instructing the workers to make iron preparations. He just saw Ji Wusheng coming, so he hurried over to report, "The ironing preparations are ready, and we are waiting for the results of the melting sample test." .”

Ji silently nodded.

"I think it will be fine this time."

"Whether there is any problem depends on the results of the laboratory." Ji Wusheng was amused by his self-confidence, "I can't see it right with my eyes!"

"Yes." Zhao Youcai replied loudly.At this time, a worker rushed over, waving a piece of paper in his hand, and Ji Wusheng knew that it was the melting test result sent by cable telegram just now by the heavy industry laboratory.

Seeing Ji Wusheng present, the worker was about to hand over the list to him, but Ji Wusheng shook his head, signaling to hand it directly to Zhao Youcai.Zhao Youcai took it and looked at it, and excitedly clenched the note into a ball. He turned around and shouted loudly, asking the workers to prepare to release the first furnace of molten silicon iron.

The casting mold smeared with coke powder is ready, and the workers are holding the steel drill, nervously waiting beside the taphole for the order to open the taphole.

Zhao Youcai pulled the cord of the warning bell, and the bell rang loudly.

"Iron!"

He gave an order, and several workers moved a hand-operated drill to the tap hole with a crane. Zhao Youcai first checked whether there was any wet mud on the mud sleeve of the tap hole, and only nodded when he confirmed that the tap hole was dry. Start drilling.

"Be steady!" Zhao Youcai shouted, carefully holding the drilling rig close to the mud hole. The temperature of the taphole is the highest in the entire blast furnace workshop. The strong heat radiation makes it difficult for people to stand there for a long time, but Zhao Youcai Still meticulously check the position of the drill bit.When drilling, the drill bit must be aimed at the center of the funnel-shaped deep pocket of the iron hole mud sleeve, otherwise the iron hole mud sleeve will be drilled or the iron hole will be drilled off, and mud will be emitted when the hole is blocked or slag and iron will be ejected out of the ditch.

"Drill!"

The workers began to shake the drilling rig, and the drill bit slowly drilled into the mud casing. After drilling a few times, the drilling rig would come out. Several workers immediately used the blowpipe drawn from the blast furnace to blow the revolving hole to blow out the drilled mud. powder.In order to observe the condition of the iron hole, whether the red point is drilled, and measure the depth of the iron hole to determine how much more drilling is required to avoid burning out the drill bit and drill pipe after drilling leakage.

"Slow down, don't rush!" Zhao Youcai stared closely at the drilling machine and the iron mouth.Starting the drilling rig is a technical task, and the movement must be very stable to prevent the drill pipe from swinging too much or the drill bit from being stuck.Drilling rig workers have been trained hundreds of times on simulated mud sleeves.

"It's tapped!" With Zhao Youcai's loud shout, the alarm bell rang again, and with the scorching flames spurting out, red molten iron surged out of the tapping hole and slanted down the main iron ditch.The taphole was suddenly shrouded in smoke.Molten iron flows out of the iron trough and is poured into the mold coated with coke powder.Choking smoke and flames rose from time to time.

With the end of the first tapping of molten iron, Ji Wusheng quietly left the blast furnace workshop.The following is the normal production process, and iron will be produced about every three hours.What he should care about is the specific element content of each batch of ferrosilicon.

There is a report on the composition of the melting sample sent in the office: the silicon content is 16.21%, which is roughly the same as their estimated ratio. Before the refining, he estimated that the silicon content of the first five batches was about 14-20%. With the change of the feeding ratio, the silicon content will rise to 17-30%.

"Here comes a good start." Ji Wusheng heaved a sigh of relief, and then looked at the overall composition report. This batch of ferrosilicon meets the needs of silicon steel making.

It is more difficult to smelt silicon steel than ferrosilicon.The smelting method prepared by the metallurgical port is to smelt silicon steel with a converter.

There are 4 small converters brought from the old time and space in the Metallurgical Gate.For the sake of prudence, Ji Wusheng decided to only use the smallest 1-ton converter.

Ferrosilicon smelting by the old time-space converter method requires oxygen blowing and argon protection, as well as RH vacuum treatment and so on.Ji Wusheng didn't have this condition, so he could only use the air blowing method as the next best thing.

Before smelting, ferrosilicon is firstly pretreated in the iron furnace, first of all, it is further desulfurized, so that the sulfur content of the molten iron entering the furnace is lower than 0.005%.As for the residual manganese and phosphorus elements in pig iron, no further treatment will be carried out.Although manganese has certain side effects on the magnetism of silicon steel, the manganese sulfide synthesized by manganese and sulfur can improve the workability of hot rolling and avoid cracking in hot rolling.As for the phosphorus element itself, it has the function of improving the iron loss, and it also has the function of strengthening the adhesion of the oxide scale on the surface of the hot-rolled plate, and it is not easy to produce an oxidized and bonded white film after annealing.However, if the phosphorus element is too high, it will also make the plate brittle, so it must be controlled under a certain content.

As for other various elements, we must try to control the content at a very low level, especially nitrogen-nitrogen element has an effect on silicon steel.In the silicon steel converter blowing process in the old time and space, one used pure oxygen, but injected argon as a protective gas during steelmaking.However, there are no two conditions for Lingao, so it can only be missing.

On the second day after the ferrosilicon was smelted, Ji Wusheng went to battle in person, and cooperated with a group of industry veterans to test the silicon steel.Due to the semi-quantitative analysis of elements that can be carried out by the spectroscopic method, for the first time in the material preparation last season, Wusheng had a rough grasp of the specific elemental composition and content of the raw materials that will be put into the converter, and can accurately prepare suitable raw materials.This is of great benefit to the work of refining special steel.

After a day and night of struggle, multiple attempts, and adjustments to ingredients and processes, they finally got good news from the analysis of molten samples in the heavy industry laboratory. They refined silicon steel with a silicon content of 3% and a carbon content of less than 0.04%.This steel is the raw material for rolling silicon steel sheets used in electric motors.

The ideal silicon content of electric motor steel is 2.4-2.8%, but this kind of steel can be regarded as a qualified material.However, it is not enough to produce suitable molten steel. Lingao’s iron and steel industry does not have continuous casting and rolling processes. The molten steel must first be cast into ingots before it can be used by hot rolling mills.

Casting steel ingots adopt mold slag technology, generally graphite powder is used, the effect of graphite powder is better, but it has obvious carbon increase, sometimes it will increase to 0.01-0.02%, which is for silicon steel with strict requirements on carbon content. Said there was a lot of damage.After several people looked through the materials, they finally decided to adopt the process of carbonized chaff husk with 70% carbon content that was used by domestic steel plants in the 40s.The ignition point of this material is much lower than that of graphite powder. The carbon in the mold slag is burned first during casting, and the carburization phenomenon is significantly reduced. Moreover, this kind of mold slag can also greatly absorb Al2O3 in molten steel, which has a great impact on reducing molten steel. The impurities have great benefits.

In order to produce this kind of carbonized chaff, Ji Wusheng took people to Xiao Bailang's activated carbon workshop to watch the kiln in advance. After dozens of experiments, he finally made carbonized chaff with 40% carbon content.

After some hard work, the Mariao Iron and Steel Consortium finally cast qualified silicon steel ingots.Then, they made persistent efforts and tested silicon steel with a silicon content of 4.1% for transformers.However, refining silicon steel with a suitable content is only half of the work-the specific quality of silicon steel depends to a large extent on the subsequent cold rolling or hot rolling process.

(End of this chapter)