SILVA, M. M.; http://lattes.cnpq.br/4819493317308583; SILVA, Marcos Mesquita da.
Résumé:
The aim of study was to evaluate the microstructural features and toughness of
the AISI 317L weld overlay deposited onto ASTM A516 Gr 60 steel substrates.
The weld overlays were carried out using the RTW-GMAW (Robotic Twin Wire
Gas Metal Arc Welding) and CWM-GMAW (Manual GMAW with addition of cool
wire) processes. For both welding processes, it was employed the AWS E317L
wire as filler metal. During weldings - using the RTW-GMAW process - two
welding heat input were employed (1170kJ/m e 1530kJ/m), and an interpass
temperature of 423K. For the CWM-GMAW process, the weldings were carried
out using two cool wire speed (Sew), SCw=25x10~3m/s e SCw=40x10~3m/s. From
coupons weld overlaid, specimens were obtained and submitted to
microstructure and microhardness analysis, and Charpy impact tests at room
temperature and 273K. The results showed an increase in dilution and heataffected
zone (HAZ) width when the heat input increased. Furthermore, it was
presented a methodology to determine - via microhardness - the quantity of HZ
in a WM/substrate interface. It was noted that the quantity of HZ was larger for
the higher heat input levels. It also was verified that the RTW-GMAW process
yielded weld overlays more uniform, less welding faults, shorter HAZ width and
higher impact toughness, as compared with the CWM-GMAW process.