Banca de QUALIFICAÇÃO: JOSÉ NAELSON DA CUNHA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : JOSÉ NAELSON DA CUNHA
DATA : 14/11/2018
HORA: 08:00
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

EFFECT OF THERMAL TREATMENT CYCLES OF TENSION RELIEF IN THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF THE API 5L X80 STEEL AFTER AISI-4130 STEEL DISSIMILAR WELD.

PALAVRAS-CHAVES:

API 5L X80 Steel, Dissimilar Welding, PWHT, ZAC Microstructure

PÁGINAS: 84
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Metalurgia de Transformação
ESPECIALIDADE: Soldagem
RESUMO:

This work aims to study the modifications in the microstructures and mechanical properties in the Thermally Affected Zone - ZAC, of API 5L X80 steel, caused by the welding processes and Post-Weld Heat Treatment - PWHT. The motivation for this work is to understand the effects on ZAC of API 5L X80 steel, after welding processes and PWHT, in dissimilar welding with AISI 4130 steel, used in the manufacture of drilling risers. For this study, a tubular welded joint with a TIG root pass and filled and coated passes with a coated electrode was submitted to 5 (five) cycles of PWHT, always with the same parameters, from which the coupons for the manufacture of Bodies of Proof - BP, with 1 (one), with 3 (three) and 5 (five) cycles of PWHT. The BPs were used for metallographic analyzes (macrography, optical microscopy and scanning electron) and mechanical tests (traction, microhardness and Charpy-V), characterization of microstructure and mechanical properties, in the three situations studied. The results show that the microstructural modifications and the mechanical properties observed in the ZAC of the API 5L X80 steel, after the welding process and the PWHT cycles, for Coupons-1, 2 and 3, did not show significant changes in the Coupons results -1 and 2, in relation to the base metal, however, the results of Cupom-3, showed losses in properties, especially in the limit of flow and microhardness. The flow limit obtained for Coupon-3 presented a loss of 23% (423.5 MPa), compared to the minimum value recommended by the API standard (552 MPa), while the other coupons were around 5% loss. The impact toughness, for the three coupons, was above 200 J, for an upper limit for 0 C of 68 J, determined by norm, considered excellent results. The microhardness showed a reduction in the values from Coupon-1 to Coupon-3, with lower values at the center of the weld, for the ZAC region, with an average of 193.5 HV, to an expected value in the base metal, close to 250 HV as indicated by the standard.

MEMBROS DA BANCA:
Presidente - 2156996 - AUGUSTO JOSE DE ALMEIDA BUSCHINELLI
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Externo ao Programa - 1938946 - NICOLAU APOENA CASTRO