The Control Of Microstructure And Performance&Software Development For Large Forgings

Due to the cross-section of large forgings，in the heat transfer process，eitherheating or cooling，there is along the section of the surface to the core part ofuneven temperature distribution.The situation is more prominent and intense in thequenching process，and even lead cracking.Because of the above phenomenon， itis difficult to remove coarse grain，mixed grain，widmanstatten，compositionsegregation and other defects of structure hereditary by conventional means thatcauses a large difference in heat treatment microstructure and properties.It isdifficult to use past experience quickly developed to meet the performance andmicrostructure of the requirements specified in the engineering contract.In recent years，with the rapid development of computer technology and theenormous theoretical and experimental progress in materials science research，thestructural steel hardenability prediction model，performance prediction model ofunfixed tempered steel and large forgings critical quenching and temperingmicrostructure and performance prediction model is integrated into the software onthe results of previous studies.The software named microstructure and performanceof large forgings control and Ansys Workbench dimensional，variable propertiesand transient quenching temperature field simulation technology for integrated usecan quickly and efficiently guide practice engineering production.The problem of H13tool steel in large cross-section after quenching crackingis that because of the complexity of the mold structure and H13steel has a strongtendency to quench cracking.Therefore，conventional methods can easily lead toquench cracking.How to develop a reasonable cooling system is also a hot issue inthe large cross-section forgings quenching.The4340v steel is based on AISI4340steel added vanadium with less relevant material；4340v transmission gear axis hashorizontal and vertical impact energy required to heat treatment process to bequenched.How to quickly develop a heat treatment process to meet therequirements is also a problem in the less relevant information premi se.Ansys Workbench can simulate the temperature field distribution of large andcomplex forgings，which gets relationship of part of the internal temperature withtime.Combination of continuous cooling curve of materials and the relationship can develop effective large section of H13tool steel cool system.Choosing areasonable heat treatment process according to the size of the ideal critical diameterprovided by the method in SAEJ406to calculate，which described the relationshipbetween structure hereditary and hardenability in the literature.The heat treatmentcan solve microstructure defects caused by the forging and get so small uniformmicrostructure of4340v steel with heat treatment after foring.Using the softwareand Ansy workbench’s quenching temperature field simulation technology canmake rapid and effective guidance for the performance of the heat treatmentprocess of4340v steel， avoiding the cost of production of the blind test.This article was first proposed that the structural steel hardenab ility predictionmodel，performance prediction model of unfixed tempered steel and large forgingscritical quenching and tempering microstructure and performance prediction modelis integrated into the software. Using the software and Ansys workbench’squenching temperature field simulation technology can be solved microstructureand mechanical properties of large forgings control problems，which has practicalsignificance for the development of heat treatment in the actual production.