A, preparation before production.
1. When you take over, check first. Understand the use of the lining, whether the production tools are complete, and whether the furnace panel is exposed.
2. Each of the two furnace seats is a group, and the ferrosilicon, medium manganese, synthetic slag and heat preservation agent are prepared in place and placed in the middle of the furnace.
3, scrap steel must be in place, if the shortage of materials can not be opened.
4. The insulating rubber mat on the stove should be placed, and no gaps are allowed.
B, normal production
1. The new furnace lining is strictly in accordance with the requirements of the new furnace baking process, and the baking time should be more than 2 hours.
2. Firstly add a suction cup to protect the furnace lining in the furnace. It is not allowed to directly add the bulk material into the empty furnace. Then, when the furnace is energized, the small material scattered around the furnace should be added to the furnace in time. The lower furnace, silicon steel sheets and punches are only used in the oven, and the rest of the time is not allowed to use.
3. The disk hoisting material is lifted from the material yard to the furnace table, and the scrap steel is sorted by the furnace worker. The sorted flammable and explosive materials are directly placed in the special inbox, and the furnace platform security is registered and confirmed.
4. The flammable and explosive special inbox is placed in the middle of two sets of furnace seats, and no one should move at will.
5. The pre-furnace feeding is mainly based on manual feeding. After the furnace scrap is carefully sorted, the material with the length less than 400mm is confirmed by the furnace chief. The material that has been carefully selected can be added by the suction cup, and the driving conductor is small for each furnace. The length of the furnace, if other people command the suction cup to feed, the trainer does not allow the feeding.
6. The suction cup should be controlled to increase the amount of addition. After the addition, the scrap is not allowed to exceed the plane of the intermediate frequency furnace. When the feeding is done, the scrap steel around the furnace mouth is cleaned. During the feeding process, the medium frequency furnace must be kept clean to prevent it. The falling of the scrap causes the induction coil or cable joint to catch fire.
7. It is strictly forbidden to pile up the amount of scrap steel on the stage. The total amount is controlled within 3 cups to reduce the difficulty of scrap sorting.
8. In the event of an explosion, the operator should immediately turn his back to the mouth of the furnace and quickly leave the scene.
9. In the pre-feeding process, for long materials, large blocks must be erected into the furnace to melt the pool as soon as possible. It is strictly forbidden to join the tile to cause the bridge. If the material is found to be bridged, the bridge must be destroyed in 3 minutes, so that the charge can be quickly melted into the molten pool. If the bridge cannot be destroyed in 3 minutes, the bridge must be destroyed due to power failure or heat preservation. Normal smelting.
10. For some heavy steels that need more than 2 people to move into the furnace, it is strictly forbidden to throw into the furnace. It should be made excessive on the furnace edge and then carefully pushed into the furnace.
11. Tubular scrap steel is added into the furnace, and the upper port of the pipe should be oriented in the direction of tapping, and it is not allowed to move in the direction of maneuvering.
12. For cold steel and short-head continuous casting billet in slag and tundish, it should be erected into the furnace after the molten steel in the intermediate frequency furnace reaches 2/3 or more, and it is not allowed to hit the furnace lining.
13. When the medium frequency furnace molten steel reaches 70% or more, it shall be sampled for analysis. The sample shall not have defects such as shrinkage holes, and no steel bars shall be inserted into the sample. After the chemical composition of the sample is obtained, the personnel of the matching elements shall be determined according to the comprehensive situation of the two furnaces. The amount of alloy added.
14. If the chemical analysis before the furnace shows high carbon, add some iron oxide blocks for decarburization. If the carbon is low, add some pig iron blocks for carbonization; if the average flow of the two furnaces is ≤0.055%, the oxidation will be exhausted when tapping. Slag, increase the amount of synthetic slag to carry out desulfurization treatment, at which time the tapping temperature must be properly increased. If the average flow of the two furnaces is ≥0.055%, the molten steel should be treated in a separate furnace, that is, the molten steel with high sulfur should be poured into the ladle. Into other furnaces, and then add some silicon steel sheet punches in the two furnaces for smelting and then tapping. If the phosphorus is high, it can only be processed in a furnace.
15. After the melting of the steel in the furnace is completed, the furnace group will carry the slag into the furnace. After pouring the slag, it is strictly forbidden to add the moist oily, painted and tubular scrap into the furnace. The dry and clean materials should be in the smelting process. Ready, after the molten steel in the furnace is full, the slag is cleaned once, and after the cleaning, the alloy is quickly added to the alloy to adjust the composition for more than 3 minutes before the steel is tapped. The purpose is to make the alloy have a uniform composition in the furnace.
16, the tapping temperature: the upper continuous casting 1650---1690; the molten iron water around 1450.
17. The temperature of the molten steel in front of the furnace is measured. According to the tapping temperature and tapping time required for continuous casting, the transmission curve is controlled. It is strictly forbidden to keep the intermediate frequency furnace at high temperature (the holding temperature is controlled below 1600 °C).
18. After the notification of continuous casting and steel is obtained, the temperature is raised rapidly. The heating rate of the intermediate frequency furnace in the liquid state of the full furnace is about 20 ° C / min before 20 furnaces; about 30 ° C / min for 20 - 40 furnaces; It is about 40 ° C / min, while paying attention to the higher the temperature inside the furnace, the faster the heating rate.
19. When the first furnace is tapped, 100 kg of synthetic slag slag is added to the ladle for heat preservation, and the second furnace is finished with steel and 50 kg of covering agent for heat preservation.
20. After the medium frequency furnace has finished the steel, carefully check the condition of the furnace lining. It is strictly forbidden to draw water into the furnace to cool down. If some parts of the lining are seriously eroded, the furnace should be carefully repaired before the furnace can be opened to replenish the furnace. All the evaporation can be added after the feed, first add a suction cup silicon steel sheet punch in the furnace, and then add other scrap steel. The first furnace after the furnace should be controlled to control the power supply curve, so that the furnace lining has a sintering process to ensure the furnace The effect is that it is strictly forbidden to add large pieces of waste to the furnace immediately after the furnace is repaired.
During the entire production process, it is strictly forbidden to expose the furnace surface to the outside.