Surface treatment – effect on spring parts in the automotive industry

  • 1 “Angel Kanchev” University of Ruse, Ruse, ul. "Studentska" 8, 7017 Studentski grad, Bulgaria


In modern automotive engineering, a particular car is composed of various parts that are manufactured using a wide variety of materials and technologies and that meet the high demands of modern customers and environmental norms. In the production process of a specific article for assembling cars, a problem with springs of a certain type is found. During the planned production, assembled products began to show the same defect. The mounted springs fall spontaneously. An analysis of the possible causes was made. A visual examination was made which showed a lack of plasticity, a change in geometry and raised doubts about the thermal surface treatment. Based on the results of the performed measurements and analysis, the possible causes of the problems during production were recognized. Several conditions could have caused this:
– Two different tools were available at the manufacturer, respectively two different technologies for the production of the springs;
– The manufacturer used two different sub-suppliers for surface treatment;
– insufficient corrosion protection;
The results of the measurements show that despite the geometric deviations of the dimensions, the springs lose their function due to lack or improper surface treatment.



  1. J.Vetter, G.Barbezat, J.Crummenauer, Surf & Coat Techn 200, 5-6 (2005)
  2. Peter Hutmann, BMW Group Munich, The Application of Mechanical Surface Treatment in the Passenger Car Industry, Ed: Prof. Dr.-Ing Lothar Wagner (2003)

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