In-Situ Measurement of Fracture Strength of Solidifying Steel Shells to Predict Upper Limit of Casting Speed in Continuous Caster with Oscillating Mold
In-Situ Measurement of Fracture Strength of Solidifying Steel Shells to Predict Upper Limit of Casting Speed in Continuous Caster with Oscillating Mold
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DOI：
10.2355/isijinternational.37.375
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发表时间：
1997-04
影响因子：
1.8
通讯作者：
Mikio Suzuki;Makoto Suzuki;C. Yu;T. Emi
中科院分区：
文献类型：
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作者：
Mikio Suzuki;Makoto Suzuki;C. Yu;T. Emi
在板坯连铸过程中，防止钢壳高速凝固裂纹的形成是提高板坯热装轧和热直轧比例的先决条件。裂纹的形成受到钢壳在其固相线温度附近的机械性能的影响。因此，采用类似于 Ackermann、Kurz 和 Heinemann 的浸没劈冷拉伸 (SSCT) 试验的方法，现场测量了含有 0.004 至 0.70 质量％ C 的凝固钢壳的断裂强度。原位SSCT试验发现，当壳厚度为2～5mm时，凝固早期的断裂强度为1～3.5MPa，低于传统热拉伸试验的断裂强度，因为裂纹在壳的枝晶间区域萌生并扩展。比较壳的断裂强度和壳/结晶器界面的摩擦力，计算出板坯连铸机的拉速上限约为8.5 m/min。
Preventing crack formation of solidifying steel shell at increasing speed in continuous slab casting operation is a prerequisite to increase the ratio of hot charge rolling and hot direct rolling of cast slabs. Crack formation is influenced by mechanical properties of the steel shell near its solidus temperature. Thus, fracture strength of solidifying steel shells containing 0.004 to 0.70 mass% C has been measured in-situ by using a method similar to Submerged Split Chill Tensile (SSCT) test by Ackermann, Kurz and Heinemann. The fracture strength at an early stage of solidification, when the shell thickness is 2 to 5 mm, has been found to be 1 to 3.5 MPa which is lower than that determined by conventional hot tensile tests, since the crack initiates at and propagates in interdendritic region in the shell in the in-situ SSCT test. Comparing the fracture strength of the shell with the frictional force at the shell/mold interface, upper limit of casting speed of slab caster is calculated to be around 8.5 m/min.