1.Steel Plant Introduction
EAF, converter and refining system: The third steelmaking plant has 4 120t converters, with a steel output of about 110t, a smelting time of about 35min, and a steel output temperature of about 1620℃. The main steel grades smelted are: Q235A, Q235B, Q345D, SS400, SPHC, HPB235, CCS-A, etc. At present, about 130 furnaces are smelted in 24 hours;
4 LF refining furnaces, with a refining ratio of 100%, a refining time of about 35min, and the temperature of the molten steel in the ladle after LF refining is between 1565 and 1595℃; 2 RH refining furnaces, with a refining time of about 25min and a RH refining ratio of about 10%.
Ladles and sliding nozzles: 47 ladles with a capacity of 120t, an actual steel output of about 110t, and 17 to 18 online turnovers. The ladle working lining is built with magnesia carbon bricks, which are contracted by Beijing Lier, Henan Zhulin and Dashiqiao Xinghua. The ladle age is between 95 and 105 times, and it has undergone 2 minor repairs and 1 medium repair. Specifically, after the new ladle is put into operation, it is used for the first time until about 30 furnaces are taken offline for minor repairs, and the nozzle seat bricks and the overall air-permeable bricks are replaced; after it is put into operation, it is used until about 60 furnaces are taken offline for medium repairs, and the slag line, ladle bottom impact zone bricks, nozzle seat bricks and air-permeable bricks are replaced; the third time it is put into operation, it is used until about 85 furnaces are taken offline for minor repairs, and the nozzle seat bricks and air-permeable bricks are replaced; after it is put into operation again, it is used until about 100 furnaces are taken offline for major repairs, and the ladle is covered throughout the process;
2.Product use environment
1. At present, the ladle slide uses Tangshan slide, which slides twice in a row. When the steel plant leader is not on site, the slide is used three times. The record of the hot repair lounge does not record the three consecutive slides. If the slide and the drain cannot be used synchronously, clean the drain and continue to use it to ensure that the drain can be used twice. The use of Tangshan’s ladle slide is stable, the continuous sliding rate reaches more than 2.0, and the slide slides three times in a row. The reason is that the steel plant stipulates that three consecutive slides are not allowed.
2. The hot rest group is divided into four shifts, and the hot repair position is divided into the east and west sides. The two platforms of the hot repair position on the east side are mainly responsible for hot repairing the ladle from the small square billet continuous casting machine, installing the spare ladle upper water inlet and preparing the ladle for baking.
The four platforms of the hot repair position on the west side are mainly responsible for hot repairing the ladle from the medium and thick plate thin slab continuous casting machine. The hot repair personnel on one side are 5 people and 1 person for oxygen burning. There are 12 people in each shift for hot repair and oxygen burning.
The following figure is a schematic diagram of our company’s skateboard:
3.the trial condition
2. From the test of slide gate plate situation, our company’s slide gate plate has been used well once and can meet the requirements of the steel plant. The following are photos of the on-site slide gate plate test
3. 5 sets of heats continuous sliding gate plates were tested, and the slideway of the lower slide gate plates of one set was slightly roughened. The anti-skid area of the lower slide gate plate of one set was delaminated. The slide gate plate was able to meet the requirements of on-site use after two consecutive sliding. The following are photos taken on site;
4. From the above photos, we can see that the slide gate plates of our company can meet the requirements of on-site use. Five sets of continuous sliding slides are installed, one of which is installed on the 2# ladle. After the 2# ladle is taken down, it needs to be put on the billet continuous casting machine to cast steel. The steel plant stipulates that the billet continuous casting machine is not allowed to use continuous sliding slides. Only the ladle slides from the billet continuous casting machine can slide continuously. The aperture of the ladle slide of the billet continuous casting machine is required to be 55mm, and the aperture of the slide we tested is 60mm. Our company’s ladle slides are used synchronously with the lower nozzle, and the lower nozzle can meet the requirements.
4.the comparison
At present, the Tangshan steel ladle slide gate plate has slid twice in a row, which is basically the same as the slide gate plat of our company that slid twice in a row. The our slide gate plat has 4 sets that have been tested for two consecutive slides, and three sets of slide gate plate have the conditions for three consecutive slides. The tangshan slide gate plate slideway also has a roughening phenomenon, but the slide gate plates steel fixing does not move. The tangshan slide gate plate was smashed open on site, and no anchor nails were installed on the steel fixing. The following are photos taken on site of the Tangshan:
5.conclusion
The sldie gaet plates test of the Handan No. 3 Steelmaking Ladle was successfully completed. The sldie gaet plate test was used twice and was able to meet the on-site conditions. There are a total of 4 sets of continuous sldie gate plates, three of which meet the conditions for 3-heats. In January, our company tracked the sldie gate plate when they were officially used for a period of time, mainly to understand the use of the sldie gaet plate and the three-stage continuous slide of the upper nozzle.
