Based On Deform Analysis Of The Grain Size And Research Of Organization Inheritance During Metal Forging And Heat Treatment

In the past30years, with the fast development of computer technology and numericalcalculation, the method of inite element simulation has been widely used in the field offorging processing. Besides, a major breakthrough has been obtained in the research ofnumerical simulation about the forging and heat treatment process. With the aid of computersimulation technology, we can forecast the microstructure evolution in the forging processing.It plays a very important role in guiding the actual production. The research subject isfinancially supported by the2009major scientific and technological projects in Guangdongprovince (2009A080304004)“Research on forging reduction of heavy forgings andtechnology of using waste heat and its application in shipping industry”.In this paper, the large forgings-35CrMo HuangChuan warships intermediate shaft isselected as the research object. And a numerical simulation has been done by using Deform inthe forging and heat treatment process. In order to study the change of grain size in theforging and heat treatment process, the secondary user subroutines DEF_USR of softwareDeform and experiment research should be done. The main research contents and conclusionsof this paper are summarized as follows:（1）Secondary user subroutines DEF_USR has been developed and the recrystallizationmodel, which the German professor R.Kopp proposed, has been embedded in softwareDeform by means of Absoft Fortran, which has managed to forecast microstructure evolutionduring forging and heat treatment process.（2）Based on the numerical simulation during the forging and heat treatment process,we can find that the grain size has reduced with the increase of anvil width. Besides, when thereduction has increased, the grain size will decreases. So in order to obtain fine grain, it’snecessary for enough anvil width. We can get the small grain size by the optimized heatingschedule. Besides the initial forging temperature is low and the heating time is shortened by4%, about0.43h. It has played a important role in reducing energy consumption.（3）During the heat treatment process, there are four factors which can influence thegrain and organization inheritance. In four factors, the heating speed is first and the heatingmeans is second. The holding time and cooling means have play a little role. What’s more, thetime of quenching heat preservation have shortened for30min. It helps reducing the energyconsumption. Besides, it can be found that enough anvil width and reduction can promotegrain refinement through the research of the relationship between forging and heat treatmentprocess. （4）In order to validate the results, a experiment is needed. During the experiment, wecan find that there is a obvious phenomenon of organization inheritance by heating slowly.Conversely, it will not be found by medium heating rate. So in order to prevent it, the heatingrate on the critical area should be improved.