Key points of production process of weather resistant steel plate
1、 Converter:
1. The charging amount shall be stable. Scrap copper shall be taken into the furnace with scrap steel at the rate of 2.8kg/t, and the furnace shall not be exchanged and other steel grades shall not be cross smelted during consumption. After the smelting of the last furnace is completed, the remaining steel and slag in the furnace shall be emptied. The next furnace shall not smelt steel grades with Cu content less than 0.10%;
2. Tapping temperature ≥ 1640 ℃, terminal carbon less than 0.06%;
3. Tapping slag material: 600kg lime+400kg synthetic slag, nickel plate shall be taken as 2.3kg/t during tapping, and other alloys shall be taken as per
The art card requests to participate (i.e. silicon manganese 4.8kg/t, ferrosilicon 2.0kg/t, low-carbon ferrochrome 17.5kg/t).
2、 Refining:
1. The deoxidizer uses calcium carbide and aluminum particles;
2. Antimony ingots (99.8% Sb content) are added after the first one, and broken antimony ingots, nickel plates and waste copper are prepared in advance;
3. Ferrotitanium shall participate 15 minutes before the package is hoisted when the deoxidation is good. If ferrotitanium is added, it shall participate 5-7 minutes after the ferrotitanium is added. The aluminum in front of ferrotitanium shall not be too high (controlled within 0.015%) to avoid adding aluminum after the ferrotitanium is added;
4. The sulfur content should not be too low, and the refining outgoing sulfur should be controlled at 0.007-0.008%;
5. In order to ensure that the superheat degree meets the company's requirements, the ladle uses a thermal turnover ladle. The superheat degree of the open casting furnace is controlled at 35-45 ℃ (it is suggested that the ladle lifting temperature be controlled at 1610-1620 ℃), and the continuous casting furnace is controlled at 20-30 ℃ (it is suggested that the ladle lifting temperature be controlled at 1575-1580 ℃).
6. The calcium in molten steel shall be disposed to ensure the wire feeding effect. The calcium feeding line shall be 250m in the pouring furnace to ensure that the calcium content of the hanging ladle sample is greater than 0.0020%. The calcium feeding line of the continuous pouring furnace shall be 100-200m in the furnace to ensure that the calcium content of the hanging ladle sample is 0.0015-0.0020%.
3、 Continuous casting (internal arc corner crack control):
1. The tundish is arranged for quick change at the start of continuous casting, and the tundish is arranged for slow change after the casting of this group is completed. Before the previous group stops pouring, contact with the water disposal department to control the primary cooling water temperature, and ensure that the water inlet temperature of the primary cooling water for this steel casting is 31-38 ℃;
2. Before pouring, the working conditions of primary cooling and secondary cooling shall be normal without blockage, the spray bar and nozzle shall be aligned without deviation, the casting blank shall not be deviated, and the specific water volume shall be 0.4L/kg;
3. Ensure that the nozzle is aligned normally without deflection;
4. After the normal start of pouring, control the temperature difference of crystallizer to 8-9 ℃;
5. Peritectic steel maintenance slag of Nikkei is selected, and 10 tubes of maintenance slag of Xibao 220 * 260 are used for standby;
6. The corner temperature of the casting billet shall be measured on site and straightened at high temperature. The temperature into the casting machine shall not be lower than 950 ℃. When the temperature is low, the casting speed can be adjusted properly;
7. Stacking cooling of slab in walking cooling bed;
8. Take 400mm long samples on different flows according to one piece/furnace to check corner cracks and low magnification analysis of longitudinal profile samples, and mark the furnace number, flow number and internal camber surface when sampling.
