3D scanning improves understanding of distortion after case hardening

Predicting distortion after case hardening is a challenge. The ultimate objective is to determine the relation between cause and effect throughout the entire process chain: steelmaking, casting, rolling, forging, machining and hardening. Although hardening is the primary trigger, all process steps can give rise to distortion.

3D scanning visualize effects of case hardening

In a joint project, Scania and Swerim have used 3D scanning to visualize distortion after case hardening of crown wheels. By scanning the crown wheel before and after case hardening, the distortions can be visualized in 3D. 

The results provide an extensive body of data for qualitative assessment; e.g., for studying how workpiece geometry, hot forging and machining method influence distortion. Scanning also enables quantitative analyze of distortions, chemical composition (charge analysis), hardenability and process parameters.

Cost savings and improved quality

Greater understanding of the factors influencing distortion has long been a concern in the field of heat treatment. Prediction of these factors enables both significant cost savings and improved product quality.

“The project has given us a better understanding of the types of distortion that occur and of how they are related to suppliers’ processes. With this knowledge, we are better able to control our own process,” says Anders Olofsson at Scania.

The study is part of an extensive ongoing research project, the aim of which is to