Influência da dupla normalização na variação dimensional após processo de cementação e têmpera do aço ETN 22

Abstract

Gears are the major mechanical components in the automotive transmission industry. One of the problems that cost the industry the most is dimensional distortion. Distortion is a phenomenon that can occur due to a wide range of reasons, and the source of the problem is difficult to detect. At Eaton Ltda one of the manufactured gears tends to have greater dimensional stability when double normalized compared to a single normalization. This stability is important as it allows process adjustments to ensure the achievement of product specifications. Thus, this work sought in the microstructure of the material a possible explanation for the narrow variation of dimensions. Residual stress, grain size, carburized layer depth and retained austenite were measured in an attempt to identify the reason for the differences that have been found. The obtained results did not show the reasons of the dimensional stability with double normalization, while the dimensional results make clear the process improvement.