基于CAFE法优化易切削钢9SMn28锰、硅、硫含量

Optimization of Manganese,Silicon and Sulfur Contents in 9SMn28 Free-cutting Steel Based on a CAFE Method

应用CAFE法,模拟了不同锰、硅、硫含量对易切削钢9SMn28凝固组织的影响,并通过热力学计算分析了原因,优化了钢中的锰、硅、硫含量,得出结论如下:Mn含量在0.9%～1.3%时,随Mn的增加,柱状晶减小;当Mn含量从0.9%到1.2%时,晶粒逐渐细化。Si含量在0.02%～0.10%时,随Si的增加,柱状晶略有减小;当Si含量从0.02%到0.08%时,晶粒逐渐细化。S含量在0.24%～0.36%时,随S的增加,柱状晶减小,晶粒逐渐细化。因此,从凝固组织方面考虑,易切削钢9SMn28的Mn、Si、S含量应分别为1.2%、0.08%、0.36%。同时,对优化了的锰、硅、硫含量进行模拟,有效的改善了9SMn28的凝固组织。

Based on a CAFE method, the effect of manganese, silicon and sulfur contents on the solidification microstructure of 9SMn28 free-cutting steel was simulated, the simulation results were analyzed using thermodynamics calculation, and manganese, silicon and sulfur contents were optimized. The results show that when the manganese content in this steel is in the range of 0.9 wt% - 1.3 wt%, the columnar dendrite zone decreases with increasing manganese content. When the manganese content is in the range of 0.9 wt% - 1.2 wt%, the grain become finer. When the silicon content in the steel is in the range of 0.02 wt% -0. 10 wt%, the columnar dendrite zone decreases slightly with increasing Si content. When the silicon content is in the range of 0.02 wt% -0.08 wt%, the grains become finer. When the sulfur content increases from 0.24% to 0.36%, columnar dendrite zone decreases and grains become finer. Subsequently, the optimumcontents of manganese, silicon and sulfur in free-cutting steel 9SMn28 are 1.2 wt%, 0.08 wt% and 0.36 wt%, respectively. In addition, the simulation result of free-cutting steel 9SMn28 with optimized composition shows that the solidification microstructure is improved obviously.