【作者】 池武；

【导师】 崔振山；

【作者基本信息】 上海交通大学 ， 材料工程， 2009， 硕士

【摘要】 本课题对轴承钢GCr15棒线材产品的控轧控冷工艺进行了研究。采用控轧控冷工艺可降低网状碳化物级别,使其达到2.0级(YJZ84标准),缩短轴承钢球化退火时间以及实现线材不经球化退火直接进行冷拉。对精轧GCr15的断面收缩率及温度对网状碳化物和晶粒细化的影响进行了实验,从而发现精轧必须给予一定量的断面收缩率或降低精轧温度,都可以获得更加细化的晶粒以及降低碳化物网状级别。利用ANSYS软件对轴承钢控轧控冷过程中的温度场进行了数值模拟并与工业试验进行了对比修正。利用数值模拟手段研究轴承圆钢冷却过程温度场是可行的,可以真实地反映圆钢断面温度变化的趋势及规律。对实现控轧控冷的冷却系统装置进行了设计和研制,对轧制过程中的断面收缩率进行了优化设计,为实现轴承钢控轧控冷提供了手段。在新建的生产线上进一步对轴承钢的控轧控冷效果进行了研究。研究出以控制网状碳化物级别及缩短球化退火时间的轴承钢棒线材最佳控轧控冷工艺参数。还研究出了GCr15线材不经球化退火而直接进行冷拉的工艺流程及工艺参数。该课题的研究成果有很好的经济及社会价值。更多还原

【Abstract】 This thesis is focused on the research of controlled rolling and cooling process of bearing steel in a new invested bar and wire rod mill. It has been proved by research that controlled rolling combined with cooling process is effective to reduce net carbide up to 2.0 grade (with reference to standard YJZ84) and not only to shorten spheroidizing annealing time but also to realize direct cold drawing of the wire rod without any further spheroidizing annealing.Made a study of the effects of the reduction rate and finishing rolling temperature on net carbide and grain size. It was finally found out that uniform fine grain and lower net carbide grade will be achieved by enough deformation or low finishing rolling temperature. Made an utilization of ANSYS software to carry out somecomputer-aided simulation on the temperature falling during the period of controlled cooling of bearing steel bar. After compared the simulated and actual measured values it was proved that it was feasible and reliable to study the temperature falling of bearing steel bar by using computer-aided simulation.The cooling system used in controlled rolling and cooling process was designed and developed. Meanwhile optimized the design for the reduction rate which aimed to carry out cotrolled rolling and cooling process of bearing steel bar and wire rod sucessfully.Further research on practical results of controlled rolling and cooling of bearing steel in new invested bar and wire rod mill has been tried on. It was found out the best process flow and parameters to reduce net carbide grade and shorten spheroidizing annealing time.Besides it was developed a new process for direct cold drawing of wire rod without extra spheroidizing annealing.The results achieved in this thesis have already been put into use and brought very good profit both in terms of economy and society.更多还原