Name: RODRIGO SOARES DOS SANTOS
Type: MSc dissertation
Publication date: 29/09/2016
Advisor:
Name |
Role |
|---|---|
| MARCELO CAMARGO SEVERO DE MACÊDO | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| MARCELO CAMARGO SEVERO DE MACÊDO | Advisor * |
Summary: The need for materials that combine high corrosion resistance and good mechanical properties makes UNS S31803 duplex stainless steel highly employable in severe corrosion environments such as the petrochemical, cellulosic, thermoelectric, marine and other industries. Its welding necessary the assembly and repair of equipment, is still endowed with some technological difficulties, such as precipitation of deleterious phases. This becomes more complex when working with thin plates, WHERE it is difficult to control the heat flux, as well as the microstructural balance (ү / α) and the incidence of deleterious phases. Thus the present work has the objective of evaluating samples of stainless steel duplex UNS S31803 of low thickness, submitted to the autogenic TIG welding process with preheating in order to make possible a better control of the molten zone. The type of current (conventional and pulsed), the pre-heating temperature and the shielding gas were varied. The balance (ү / α) and double-cycle potentiodynamic electrochemical reactivation (DL-EPR) tests were evaluated to evaluate the corrosion resistance of this region. The microstructural characterization was evaluated by means of optical microscopy and Scanning Electron Microscopy (SEM). It was verified that the type of current, the preheating temperature and the shielding gas influenced the microstructural balance as well as the corrosion resistance.
Keywords: Stainless Steel Duplex UNS S31803, TIG welding, preheating temperature, Corrosion
