Cofiño-Villar Alberto, Alvarez-Antolin Florentino, Asensio-Lozano Juan
Materials Pro Group, Departamento de Ciencia de los Materiales e IngenieríaMetalúrgica, Universidad de Oviedo; Independencia 13, 33004 Oviedo, Spain.
Materials (Basel). 2019 Apr 20;12(8):1304. doi: 10.3390/ma12081304.
To ensure the formation of a sound shell-core bond interface free of defects between the shell and the core in work rolls used in the finishing stands of hot strip mills, a complete fusion of this interface must be achieved, avoiding excessive mixing of the two components and the formation of hard, fragile microstructures. The shell is made of white cast iron, alloyed with Ni and Cr, and the core is manufactured of grey cast iron spheroidal graphite in a pearlitic matrix. It is thus advisable to inoculate the shell with 0.6 kg/T SiCaMn, as this promotes discontinuity in the carbide network and leads to an increase in the impact toughness of the bond interface. Furthermore, inoculation of the shell with FeSi-La should be avoided, as this inoculant leads to an increase in graphite counts, promoting it with a lamellar morphology at the edge of the bond and hence reducing the impact toughness in this interface. Addition of Mg to the shell has been found to produce an increase in hardness in the regions adjacent to the bond interface.
为确保热轧带钢精轧机架工作辊中，在外壳与芯部之间形成无缺陷的良好壳-芯结合界面，必须实现该界面的完全熔合，避免两种成分过度混合以及形成硬而脆的微观结构。外壳由含镍和铬的白口铸铁制成，芯部由珠光体基体中的球墨铸铁制造。因此，建议在外壳中加入0.6 kg/T的硅钙锰进行孕育处理，因为这会促进碳化物网络的间断性，并导致结合界面的冲击韧性增加。此外，应避免在外壳中使用硅铁-镧进行孕育处理，因为这种孕育剂会导致石墨数量增加，在结合边缘促进形成层片状形态的石墨，从而降低该界面的冲击韧性。已发现向外壳中添加镁会使结合界面附近区域的硬度增加。
