Study on Corrosion Behavior of Ti-Ni-Nb Shape Memory Alloy and 1Cr18Ni9Ti Stainless Steel Aeroplane Pipe System
The susceptibility to stress corrosion cracking (SCC) and galvanic corrosion of an aeroplane pipe made of 1Cr18Ni9Ti connected with a pipe coupling that made of Ti-Ni-Nb shape memory alloy were evaluated. SCC test was completed under simulated service environment in 6% NaCl solution through a self-designed corrosive system. Galvanic corrosion behavior of Ti-Ni-Nb/1Cr18Ni9Ti couple was conducted in 3.5% NaCl solution at 30°C, in which galvanic corrosion current (Ig) and galvanic corrosion potential (Eg) were monitored. The corrosion morphology was observed by using scanning electronic microscope (SEM) and optical microscope (OM) after SCC test and galvanic test. It was showed that no obvious corrosion was detected on the surface of the whole pipe system after the simulated test. The two metals showed excellent resistance to SCC based on the section morphology observation. The average galvanic corrosion current of 1Cr18Ni9Ti/Ti-Ni-Nb couple was 0.13µA/cm2. No obvious corrosion pitting was detected on the surface of the two alloys by OM observation. Therefore, 1Cr18Ni9Ti pipe was safely connected with Ti-Ni-Nb pipe coupling in aeroplane pipe system.
David M. Batisdas and Y.Q. Chang
J. X. Shi and J. H. Liu, "Study on Corrosion Behavior of Ti-Ni-Nb Shape Memory Alloy and 1Cr18Ni9Ti Stainless Steel Aeroplane Pipe System", Advanced Materials Research, Vol. 668, pp. 808-813, 2013