铸坯碳偏析对Q345E低温冲击性能的影响

 为了适应风电法兰恶劣的工作环境，提高使用寿命，对风电法兰用钢Q345E低温冲击性能提出了在－50 ℃测试的要求，而且内外部性能要求均匀一致。为了提高Q345E钢的心部力学性能， 采用不同连铸工艺生产了具有不同凝固组织的圆坯， 分析了铸坯碳偏析对力学性能的影响，为改善Q345E钢心部的力学性能提供了依据。结果表明， 提高铸坯等轴晶率和细化凝固组织可降低铸坯心部的碳偏析程度，能显著提高钢材内部力学性能的均匀性。

Effects of carbon segregation of billet on Q345E low temperature impact energy

With more abominable working environment and prolonging service life，Q345E steel for wind power flange needs to have low temperature impact property under －50 ℃. Besides，the interior and exterior mechanical property of the steel grade needs to be uniform. In order to improve the mechanical properties of Q345E steel in the core portion，the effects of carbon segregation of billet on the mechanical properties are analyzed using billets of various solidification structures produced with different continuous casting processes. Results show that the carbon segregation in the core portion can be reduced and thus the uniformity of the interior mechanical properties of the steel prominently raised by improvement in the equiaxed crystal ratio and refinement of the solidification structure.