Title

ANÁLISE DE TENSÕES RESIDUAIS EM BARRAS DE AÇO AISI 1048 PRODUZIDAS POR TREFILAÇÃO COMBINADA

ANALYSIS OF THE RESIDUAL STRESSES IN AISI 1048 STEEL BARS INDUCED BY COMBINED DRAWING-STRAIGHTENING PROCESS

Authorship

Nunes, Rafael Menezes; Metz, Maurício; Hirsch, Thomas; Rocha, Alexandre da Silva

Nunes, Rafael Menezes

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Metz, Maurício

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Hirsch, Thomas

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Rocha, Alexandre da Silva

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DOI

10.5151/2594-5327-2005-15975-0036

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Abstract

As tensões residuais podem afetar positiva ou negativamente o desempenho dos componentes mecânicos. Estas tensões residuais também representam um dos principais potenciais para a distorção (isto é empenamentos e mudanças dimensionais) em componentes mecânicos durante a manufatura. Por isso são de grande importância a determinação da distribuição e o controle destas tensões residuais em cada etapa do processo de manufatura. Neste trabalho, foram realizadas análises da variação das tensões residuais em barras trefiladas de aço AISI 1048 em decorrência do processo de fabricação. As barras foram retiradas após cinco diferentes etapas do processo de trefilação combinada guardando-se a orientação inicial do fio-máquina, sendo elas: pré-endireitamento, jateamento, trefila, endireitamento e polimento por rolos cruzados (PTN) com ângulos de 16

The residual stresses can affect positively or negatively the behavior of mechanical components. These residual stresses also represent one of the main potentials for distortion (i.e. bending and dimensional changes) in mechanical components during the manufacture. Therefore the determination of the distribution and the control of these residual stresses in each stage of the manufacturing process are of great importance. In this work the variation of residual stresses in cold-drawing of AISI 1048 steel bars due to the production process was analyzed. Samples were taken from five different stages of the process of combined cold- drawing with special care to keep the information about initial orientation. The process steps from where samples were taken were: pre-straightening, shot-blasting, drawing, straightening and polishing in crossed rolls (PTN) with angles of 16° and 18°. The determination of residual stresses was accomplished by the hole drilling method. The measurements were done until a depth of 1 mm in different angular positions on the periphery to characterize heterogeneities imposed by the process. Starting with the obtained strains, the residual stresses were calculated in the longitudinal and tangential directions for each measurement point. With this work a global view of the developed stresses in the surface of the bar after each process stage was obtained.

Keywords

Trefilação combinada; Tensões residuais; Método do furo; Hole-drilling.

Combined cold-drawing; Residual stresses; Hole-drilling.