MODELAGEM ESTATÍSTICA POR REGRESSÃO NÃO LINEAR DO EFEITO DA DUREZA SOBRE A CONFORMABILIDADE DO AÇO SAE 1045 TREFILADO

Abstract

Formability is the material's ability to plastically deform, in forming processes, without damage to mechanical, dimensional, metallurgical and visual requirements. There are several factors that influence formability, such as chemical composition, microstructure, surface finish, work hardening and hardness being. In this context, this research measured the effect of hardness on the SAE 1045 drawn steel formability, through hardness and compression tests on samples under the effect of different heat treatments. In addition to being analyzed as supplied, the samples of the analysis material were subjected to six different heat treatments: annealing, normalization, coalescence, water hardening, oil hardening, and oil hardening followed by tempering, in order to understand a wide range of hardness and compression deformations as a result of subsequent mechanical tests. The compatibility of the microstructure obtained with the heat treatment applied was verified by means of metallographic analysis to verify the success of the process and the expectation in relation to the test data. After analyzing the hardness-deformation ordered pairs, the statistical model that predicts the exponential behavior of the conformability decay with increasing hardness was presented, with satisfactory correlation values ​​validated via the coefficient of determination.