Guo Junli, Wen Guanghua, Pu Dazhi, Tang Ping
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
Materials (Basel). 2018 Apr 7;11(4):571. doi: 10.3390/ma11040571.
The contraction of peritectic steels in the initial solidification has an important influence on the formation of surface defects of continuously cast slabs. In order to understand the contraction behavior of the initial solidification of steels in the mold, the solidification process and surface roughness in a commercial hypo-peritectic and several non-peritectic steels were investigated using Confocal Scanning Laser Microscope (CSLM). The massive transformation of delta-Fe (δ) to austenite (γ) was documented in the hypo-peritectic steel, which caused surface wrinkles and greatly increases the surface roughness of samples in the experiments. Surface roughness (R) was calculated to evaluate the contraction level of the hypo-peritectic steel due to δ-γ transformation. The result shows that the surface roughness method can facilitate the estimation of the contraction level of peritectic transformation over a wide range of cooling rates.
包晶钢在初始凝固过程中的收缩对连铸板坯表面缺陷的形成有重要影响。为了了解钢在结晶器内初始凝固的收缩行为，利用共聚焦扫描激光显微镜（CSLM）研究了一种工业亚包晶钢和几种非包晶钢的凝固过程及表面粗糙度。在亚包晶钢中记录到了δ-Fe（δ）向奥氏体（γ）的大量转变，这导致了表面皱纹的出现，并在实验中大大增加了样品的表面粗糙度。计算表面粗糙度（R）以评估亚包晶钢因δ-γ转变而产生的收缩程度。结果表明，表面粗糙度方法有助于在较宽的冷却速率范围内估算包晶转变的收缩程度。
