Crevice corrosion behaviour and mechanism of laser additive manufacturing nickel-based alloy by using wire beam electrode

The wire beam electrode (WBE) of laser additive manufacturing (LAM) nickel-based alloy was prepared to help study its crevice behaviour and mechanism at different area in the crevice with different size. The results show that the LAM nickel-based alloy with the crevice size of 0.1 and 0.3 mm presents crevice corrosion characteristics at 1 day and 3 days due to the formation of oxygen-concentration cell at the former two cases caused by the difficult migration of oxygen from the outside into the crevice. The corrosion at the middle and inside of the crevice is more serious than the outside, which is reflected by the 29.92% lower contents of O2- at the inside than that at the outside of the crevice. Locally, inter-phase corrosion appears between the uniform nickel-based alloy matrix and the insoluble oxides at the inside of the crevice.