Optimization of the heat treatment of high-strength, sintered gears

 

Starting Situation

The heat treatment of porous materials is currently proving challenging and involves increased effort in process adjustment. The porosity of the gears leads to accelerated carbon diffusion, which is why carburization can also reach deeper material areas under conventional heat treatment parameters and result in an undesirable depth of hardness profile. The specification of the heat treatment parameters is made more difficult by the compaction of the material in the edge zone, since there is a gradient in the porosity above the material depth.

Research Objective

The aim of the research project is to establish practice-oriented guidelines for the application of case hardening of components made of sintered steel with a density profile. For this purpose, FE models will be developed which can map the heat treatment of a material with variable density and thus make it accessible for targeted analysis. These models are used to optimize case hardening by varying the process parameters. The results are verified by heat treating and testing a test series of densely rolled gears with optimized process parameters and then comparing them with a test series of reference gears. The load capacity of the gears is tested on a running test bench and a pulsator test bench.