摘要
对B510L钢在全流程生产过程中不同位置取样,研究了钢中非金属夹杂物的变化情况。结果表明,钙处理前夹杂物主要为Al_(2)O_(3),由于RH精炼过程钢液中氧含量较低而硫含量相对较高,加入过量的钙后生成了大量CaS夹杂物,CaS含量高达60%,Al_(2)O_(3)含量降低至30%,夹杂物变为CaS-Al_(2)O_(3)-CaO的复合夹杂物。连铸过程中发生二次氧化,钢液中氧含量增加,夹杂物中Al_(2)O_(3)含量增加,CaS含量降低,夹杂物转为钙铝酸盐。随着冷却过程的进行,钢基体与夹杂物之间的热力学平衡发生转变,夹杂物中CaO含量降低,夹杂物变为Al_(2)O_(3)-CaS的复合夹杂物。使用热力学软件Factsage计算了不同钙含量及氧含量对钙处理过程夹杂物变化的影响以及冷却过程中夹杂物的析出情况。随钢中钙含量增加,夹杂物中Al_(2)O_(3)含量逐渐降低,CaO以及CaS含量增加,当钢中钙含量超过12 ppm时,由于固体CaS夹杂物的大量生成,夹杂物总量增加明显。随着钢中氧含量增加,夹杂物中CaS含量降低,液态夹杂物数量增加,夹杂物总量增加。随温度降低,钢中CaO夹杂物在1 310℃左右时消失,1 280℃开始生成MnS夹杂物,钢中CaS与液态的钙铝酸盐夹杂物逐渐演变为Al_(2)O_(3)-CaS复合物,由于CaS以及MnS夹杂物的生成,夹杂物总量逐渐增加。
The B510L steel samples were taken during the production process to study the evolution of inclusions.The main composition of inclusions before Ca treatment was Al_(2)O_(3) and a large amount of CaS generated because of the higher sulfur content and lower total oxygen content after excessive Ca addition to the molten steel.The CaS content increased to 60%while the Al_(2)O_(3) content decreased to 30%so that the inclusions changed to CaS-Al_(2)O_(3)-CaO complex inclusions.Secondary oxidation phenomenon occurred during the continuous casting process,leading the increase of oxygen content.The Al_(2)O_(3) content increased while the CaS content decreased due to the increase of oxygen content in molten steel.During the cooling process,CaS inclusions gradually precipitated and inclusions became Al_(2)O_(3)-CaS complex inclusions.The effect of T.Ca and T.O.contents on the inclusions transformation during the Ca treatment process and the precipitation of inclusions during cooling process were also calculated using the thermodynamic software Factsage.The Al_(2)O_(3) content in inclusions gradually decreased while the CaO and CaS contents increased with the increase of T.Ca content.When the calcium content in the steel exceeded 12 ppm,the total amount of inclusions increased significantly due to the generation of solid CaS inclusions.The CaS content in inclusions decreased,the number of liquid inclusions increased,and the total amount of inclusions increased with the increase of T.O content in the steel.With the temperature decrease,CaO inclusions in the steel disappeared at 1310℃,and MnS inclusions began to form at 1280℃.The CaS and liquid calcium aluminate inclusions in the steel were gradually transformed into Al_(2)O_(3)-CaS composite inclusions.Due to the formation of CaS and MnS inclusions,the total amount of inclusions gradually increased.
作者
李成龙
代平
李世良
王伟健
张立峰
Li Chenglong;Dai Ping;Li Shiliang;Wang Weijian;Zhang Lifeng(Ironmaking Plant of Shandong Iron and Steel Group Rizhao Co.,Ltd.,Rizhao 276800,Shandong;School of Mechanical and Materials Engineering,North China University of Technology,Beijing 100144,China)
出处
《河北冶金》
2025年第6期40-45,65,共7页
Hebei Metallurgy
基金
国家重点研发计划(2023YFB3709900)
国家自然科学基金(U22A20171,52304341)。
关键词
B510L
二次氧化
夹杂物析出
热力学计算
钙含量
钙铝酸盐
B510L
secondary oxidation
precipitation of inclusions
thermodynamic calculation
calcium content
calcium aluminate salt
