碳与磷含量对易切削钢9SMn28微观组织的影响

Effects of carbon and phosphor contents on microstructure of a free-cutting steel 9SMn28

应用元胞自动机-有限元模型（CAFE）,模拟了不同碳、磷含量对易切削钢9SMn28凝固组织的影响,并通过热力学计算分析结果,优化了钢中的碳、磷含量。模拟结果表明,C含量在0.09 wt%-0.16 wt%时,随C的增加,柱状晶随之而减小;C含量从0.09 wt%增加到0.15 wt%时,晶粒逐渐细化。P含量在0.02 wt%-0.10 wt%时,随P的增加,晶粒逐渐细化。同时,对C、P模拟结果进行了实验验证,实验与模拟结果吻合较好。因此,易切削钢9SMn28的C与P含量应该分别取0.15 wt%及0.10wt%,可以有效地改善9SMn28的凝固组织。

Based on cellular automaton-finite element model（CAFE）,the effects of solidification microstructure of 9SMn28 free-cutting steel with different carbon and phosphor contents were simulated.The simulation results were analyzed by use of thermodynamics,and carbon and phosphor contents were optimized.The results show that when the carbon content in this steel is from 0.09 wt% to 0.16 wt%,the higher the carbon content is,the smaller the columnar dendrite is, and the grain size decreases with increasing the carbon content at 0.09 wt%-0.15 wt%.When the phosphor content is from 0.02 wt% to 0.10 wt%,the sizes of the columnar dendrites and grains decrease with the increase of phosphor content.The simulation results were validated by experiment.Therefore, the contents of carbon and phosphor in free-cutting steel 9SMn28 are determined to be 0.15 wt% and 0.10 wt%,respectively,and the solidification microstructure in the free-cutting steel 9SMn28 with this composition is improved obviously.