Abstract:In order to improve the cleanliness and comprehensive properties of hot-rolled pickling plate produced by CSP process. The inclusions in QSTE500TM (hot rolled pickling plate for automobile structure) smelting process and hot-rolled coil through the CSP process were studied. The variation route of inclusions in the process of smelting is Al2O3-SiO2-MnO→Al2O3→MgO-Al2O3-CaO-CaS→Al2O3-CaO-CaS. Before the LF calcium treatment to tundish, the total amount of inclusions in molten steel remains unchanged, is about 200 μm2/mm2. The total amount of inclusions in the hot-rolled coil is about 2 times of that in molten steel. The main inclusion is large MgO-Al2O3-CaO-CaS, small TiN precipitates, and medium-size Al2O3-CaO-TiN complexes. The mass percent of TiN in complex inclusions varies from 10% to 100%. With the increase of TiN content, the size of inclusions decreases gradually. The density of inclusions below 10 μm in different positions of the hot-rolled coil is almost the same, and the inclusions above 10 μm are the most at 1/4 of coil width. With the increase of nitrogen content, the content of inclusions in hot rolled coil increases.The precipitation of the second phase in the hot-rolled coil is more uniform under the CSP process, which is beneficial to the final mechanical properties of the products. Considering the process control ability and product performance requirements, it is suggested to strictly control the protective casting of CSP hot-rolled pickling plate with nitrogen mass percent below 0.006 0%.
隋亚飞, 邓之勋, 赵如, 齐江华. CSP产线下汽车结构用热轧酸洗板中的夹杂物[J]. 钢铁, 2021, 56(4): 44-51.
SUI Ya-fei, DENG Zhi-xun, ZHAO Ru, QI Jiang-hua. Inclusions in hot rolled pickling plate for automobile structure through CSP process[J]. Iron and Steel, 2021, 56(4): 44-51.
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