Influência da severidade de têmpera no comportamento dimensional e metalúrgico após processo de têmpera no aço ETN 25 cementado

Abstract

Shafts are mechanical components of great importance within the automotive transmission sector. They are responsible for transmitting the rotation and torque movement from one point to another. One of the problems that most cause financial impact on industries is dimensional distortions. The distortion can occur due to several factors, which can be minimized, but not eliminated. At Eaton Ltda., one of the highest rates of rejection of parts in the heat treatment, occurs in the straightening operation, which is responsible for correcting the dimensional variation and leaving the part within the specified tolerance. Hence, this work sought to understand the influence of the quenching severity on the dimensional and metallurgical behavior of a shaft. Measures of radial beat, residual tension, grain size, depth of carburized layer and retained austenite were performed in an attempt to understand the reason for the variations found. The metallurgical results found do not demonstrate in a concrete way why the improvement in the operation of straightening, while the improvement in the results of the dimensional behavior makes clear the influence of the change in the severity of quenching.