10236 Corrosion Resistance of Ni-Cr-Mo and Ni-Mo-Cr Alloys in Different Metallurgical Conditions

Available for download

Product Number: 51300-10236-SG

ISBN: 10236 2010 CP

Author: Raul Rebak, Natalia Silvina Zadorozne, Ricardo Carranza, Martin Rodriguez and Nacera Sabrina Meck

Publication Date: 2010

Member Price: $0.00

Non Member Price: $20.00

Price: $20.00

Qty:

Ni-Cr-Mo alloys offer an outstanding corrosion resistance in a variety of highly-corrosive environments. This versatility is due to the beneficial effects of Cr and Mo in oxidizing and non-oxidizing conditions, respectively. Alloy 22 (Ni-22%Cr-13%Mo-3%W) is a well known member of this family, while alloys Ni21Cr17Mo and Ni15Cr22Mo have been introduced recently. Alloy Ni21Cr17Mo is age hardenable and Alloy Ni15Cr22Mo is able to deal with reducing acids with oxidizing species. Aging of Ni-Cr-Mo alloys lead to different microstructure changes depending on the temperature range. A long range ordering reaction occurs between of 350ºC and 600ºC, producing an ordered Ni2(Cr,Mo) phase. Tetrahedral close packed phases precipitate at grain boundaries in the range of 600ºC to 1100ºC.

The aim of the present work was to compare the corrosion rate and the crevice corrosion susceptibility of Ni-Cr-Mo alloys in different metallurgical conditions when exposed to chloride solutions at 90ºC. All the tested alloys showed similar corrosion rates in 1M NaCl. In 1M HCl solution, Alloy Ni15Cr22Mo had the best performance. The corrosion rate in 1M HCl and the crevice corrosion resistance in 1M NaCl of the alloys were determined by their Mo content. As the Mo content increased, the corrosion rate decreased, and the resistance to crevice cor-rosion increased.

Keywords: nickel alloys, Ni-Cr-Mo alloys, N06022, chloride, crevice corrosion