Goldak Technologies

VrHeatTreat Highlights

Automatic meshing of a gear. The user picks a few points in a GUI and specifies the desired number of elements in the mesh. Meshing requires about 5 minutes on an Intel Core 2 processor to generate very high quality curvilinear brick meshes. Furnace heating is specified by a time dependent convection boundary condition with furnace temperature and convection coefficient. A transient 3D thermal analysis computes the 3D temperature as a function of time for the complete heat treating process. Carburization is specified by a time dependent carbon potential. A transient 3D solute diffusion analysis computes the carbon concentration as a function of time. Quenching is specified by a time dependent convection boundary condition with quench temperature and convection coefficient. The lowering of a part into a quench bath can be simulated by specifying the orientation and position of the part as a function of time as it is lowered into the quench media The evolution of microstructure is simulated. Usually a ferrite-pearlite microstructure evolves to an austenite that is carburized. On quenching the austenite transforms to martensite and bainite. The effect of the variation of carbon concentration on microstructure evolution is included, e.g., austenite with higher carbon levels has a lower Ms temperature for the start of the transformation to martensite. During this entire heating, carburizing and quenching process, the 3D transient stress, strain and displacement are computed. All of these analyses are 3D non-linear, transient and coupled. The expansion due to both temperature changes and phase changes is included. The end result of the simulation is a prediction of the distortion, microstructure, hardness and residual stress in the gear. VrHeatTreat software is designer driven. This means that anyone in the design, development, manufacturing, operations and maintenance team could use the software. The computing time on a single Intel Core 2 processor is about 12 hours for a gear meshed with 100K elements. More important, the user time to set up an analysis for heat treating a typical gear is less than one hour. A single gear set for a tractor manufacturer can take a team of several engineers three to five years to develop. Today gears are often manufactured to tolerances as tight as 2 microns over lengths as long as 50 cm. The carburized layer is often 2 mm thick. It is critical that distortion and residual stress on quenching be carefully controlled. Also the hardness and microstructure must be controlled carefully. We believe that VrHeatTreat is the best heat treating simulation software available.