奥氏体晶粒尺寸对工艺参数的灵敏度方程及应用

Sensitivity equations of process parameters for austenite grain size and its application

为了便捷、准确地确定工艺参数对奥氏体晶粒尺寸的影响规律,考虑热加工工艺参数间的耦合关系,基于Hodgson再结晶模型建立奥氏体晶粒尺寸对工艺参数的灵敏度方程,探讨工艺参数对奥氏体晶粒尺寸的影响.研究表明:在单道次热加工过程中,变形速率、变形量、间隙时间、初始晶粒尺寸、间隙温度和变形温度灵敏度依次降低,工艺参数在不同的工艺过程中灵敏度不同;在多道次热加工过程中,工艺参数的灵敏度还与工艺参数所在道次和总道次数有关.H型钢开坯过程灵敏度分析结果表明,温度和后两个道次间隙时间是奥氏体晶粒尺寸的关键影响因素;降低温度并缩短间隙时间可以将H型钢开坯后的奥氏体晶粒尺寸减小26.2%.

The sensitivity equations of process parameters on the austenite grain size were suggested in order to determine the rules affecting austenite grain size quickly and accurately .These equations were based on the Hodgson recrystallization models of low carbon steel ,and coupling relationships of processing parameters for hot working were considered in these equations .Results showed that the sensitivities of strain rate ,strain ,inter pass time ,initial grain size ,deformation temperature and inter pass temperature successively decreased during single‐pass hot processing .The sensitivity values were dependent on the specific process .Results showed that the sensitivities of process parameters were associated with the total pass number of hot working and the specific pass of the process parameters because these parameters were changed during multi‐pass hot processing .These achievements were applied to the cogging process of H beam .T he sensitivity analysis indicates that the deformation temperature and inter pass time of the last two passes are the key factors affecting on the finishing grain size of H beam .Austenite grain size can be reduced by 26 .2% when the deformation temperature is lowered and the inter pass time is shorten .