Gear Deformations During Heat Treatment

The solution presented in the diploma thesis is satisfactory. The work supports theoretical explanations with practical tests. The sample furnace batches were provided with identical conditions, so that all samples were taken from one metallurgical batch, machined with one machining needle, and placed numbered in identical positions according to the scheme. The main finding obtained from theory and practice is that we can influence the deformation of the shaft gear, which was also proven. Deformation can be reduced and increased, which means less dependence on machining before hardening – machining.

Problem

The solution presented in the diploma thesis is satisfactory. The work supports theoretical explanations with practical tests. Our goal was to determine the reason for the sudden change in deformation and to reduce the scatter of gear deformations to the tolerance range.

They focused on the latter.

Solution and Method

The sample furnace batches were provided with identical conditions, so that all samples were taken from one metallurgical batch, machined with one machining needle, and placed numbered in identical positions according to the scheme. All sample pieces were measured twice with a taper gauge, before the heat treatment process and after the completed heat treatment process. All measurements were documented.

Results

The main finding obtained from theory and practice is that we can influence the deformation of the shaft gear, which was also proven. Deformation can be reduced and increased, which means less dependence on machining before hardening – machining. The consequence of introducing material cooling in the cooling chamber (with a loop) is ** reduction of deformation and scatter of shaft gear deformation**.

With this procedure, they will achieve a higher yield of good pieces in the future. Through constant monitoring and measurements, they determined the influence of cooling on deformation changes. The measurement results show that the measured scatter values decrease and are also smaller than the tolerance range of gear size after heat treatment when cooling with a loop. ** The cooling method has no influence** on surface hardness and carburising depth, which was proven by metallographic analysis.

After heat treatment, we currently have a larger proportion of pieces for gear repair with so-called hard grinding. In the future, we can expect that there will be significantly fewer of these pieces and thus ** costs will be reduced** due to additional machining.