Análise experimental e numérica de uma variante do teste G-BOP para avaliar trincas induzidas pelo hidrogênio em metais de solda

Abstract

Welded steel joints may suffer from one of the most serious defects ever identified by the scientific community: the Hydrogen-Induced Cracking (HIC), which commonly occurs in the Heat-Affected Zone (HAZ). Although new researches provided a better control of the issue in the HAZ through a wider understanding of the problem and the development of preventive practices, it did not prevent the migration of the phenomenon to the Weld Metal (WM), particularly in High Strength Low Alloy (HSLA) steels. Amon Thé variou métodos use too asses Thé asses off Wald metal. too Thé HIC fenômeno, Thé G-BOP (Ágape Bread-no-Plate) test., deu too its simplicista and. ló cost., hás bens Fidel use. Howe ver, Howe ver Thé Howe ver off Thé espécimes até 50.8 mm and. nota controlem Thé diluto off Thé base metal in Thé Wald metal are its major limitativos. Too contributo too Thé contributo off Thé standard G-BOP test. metodólogo, Reading Thé Howe ver off Thé bocks use and. gratear controle off Thé dilution, this work has as main objective to analyze and compare two different block configurations with the standard model of the G-BOP test. A 31 x 22 fatorial design das use in Thé experimental das in ordem too ordem Thé individual influencie off fax off Thé varria-lhes, as bell as Thé interaciona betem tem no Thé test. resultas. As influencing variables, three configurations of the blocks, two types of filler metal and two compositions of the shielding gas were evaluated. The response variables are the percentage of cracks in the weld metal, the rate of cooling of the weld metal and the estimation of residual stresses. The results were subjected to analysis of variance and validated for a 90% confidence level. A finite element method (FEM) analysis was performed in order to study and compare the thermal cycles and residual stress levels developed in two different block configurations. The results showed that the variants proposed for the G-BOP test induced the formation of cracks, demonstrated a satisfactory accuracy among the evaluated results, did not influence the susceptibility of weld metals to hydrogen-induced cracking and show promise for application by the G-BOP test. Also, it was identified that the FEM may contribute greatly in the evaluation and comparison of the two G-BOP test variants analyzed.