Susceptibility to galvanic corrosion of base AISI 316L/welded AISI 316L thermocouples in LiBr solution

摘要

The effect of microplasma arc welding (MPA) on the electrochemical and corrosionbehaviour of AISI 316L stainless steel tubes has been studied by means of scanningelectrochemical measurements (SECM) and Zero-resistance ammeter (ZRA) tests.SECM measurements were performed in NaCl to evaluate the difference in theelectrochemical activity of base and welded samples. Oxygen reduction ratesincrease in AISI 316L as a consequence of the heat treatment used, indicating ahigher electrochemical activity in the welded samples. The use of MPA weldmentswas studied in lithium bromide (LiBr) absorption machines at different temperaturesand Reynolds numbers. ZRA tests show that the galvanic pair generated betweenthe base and welded alloys is weak and electrodes are in their passive state.