Table 1 Tabulation of reported corrosion characteristics of some CCAs
System | Molar ratio (X) | Test | Electrochemical parameters | Localised corrosion | Comments | Reference | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
OCP | Potentiodynamic polarisation | EIS | Mass loss | Electrolyte | E corr (mVSCE) | i corr (A/cm2) | E pit (mVSCE) | |||||
AlxCrFe1.5MnNi0.5 | 00.30.5 | ✗ | ✓ | ✓ | ✗ | 0.5 M H2SO4 1 M NaCl | −473−438−450 | 6.86 × 10−42.39 × 10−35.08 × 10−3 | ✗✗✗ | ✗✓✓ | High free corrosion rate reported, however an active-passive transition occurs. This leads to a wide passive region in acidic solution; Al reported to impair corrosion resistance in both electrolytes tested | |
AlxCoCrFeNi | 00.250.51 | ✓ | ✓ | ✓ | ✓ | 0.5 M H2SO4 | −325−339−328−338 | 15.8 × 10−616.7 × 10−613.4 × 10−613.1 × 10−6 | ✗✗✗✗ | ✓ | Wide passive region. Better general corrosion resistance than 304 SS | |
FeCoNiCrCu0.5Alx | 0.511.5 | ✗ | ✓ | ✗ | ✗ | 0.5 M NaCl 0.5 M H 2 SO 4 | −286−288−443 | 1.31 × 10−68.21 × 10−71.87 × 10−5 | ✗✗✗ | Not reported | As-cast FeCoNiCrCu0.5Al alloy exhibits better corrosion resistance than 321 SS in acidic solution based on potentiodynamic polarisation test | |
Al0.3CrFe1.5MnNi0.5Tix | 00.2 | ✗ | ✓ | ✗ | ✗ | 0.6 M NaCl | −230−310 | 2.41 × 10−87.34 × 10−7 | ✗✗ | Not reported | Small amount of Ti (x = 0.2) addition deteriorates the corrosion resistance | |
Al0.3CrFe1.5MnNi0.5Six | 00.2 | ✗ | v | ✗ | ✗ | 0.6 M NaCl | −230−300 | 2.41 × 10−84.71 × 10−8 | ✗✗ | Not reported | Small amount of Si (x = 0.2) slightly increased the corrosion rate | |
Al2CrFeCoCuNiTix | 00.511.52 | ✗ | ✓ | ✗ | ✗ | 0.5 M HNO3 | −180−300−330−300−150 | 3.8 × 10−52.2 × 10−57.3 × 10−64.4 × 10−62.7 × 10−6 | ✗✗✗✗✗ | Not reported | Better general corrosion resistance than Q235 steel (roughly equivalent to ASTM A36 mild steel) | |
As-cast AlCoCrFeNi | ✗ | ✓ | ✗ | ✗ | 0.6 M NaCl | −294 | 9.30 × 10−8 | ✗ | ✓ | The Al-rich, Cr-lean dendrites suffer from selective dissolution. The alloy has better corrosion resistance than AISI 1045 steel | ||
Co1.5CrFeNi1.5Ti0.5Mox | 00.10.50.8 | ✗ | ✓ | ✗ | ✗ | 0.5 M H 2 SO 4 , 1 M NaCl 1 M NaOH | −687−625−737−795 | 5.7 × 10−71.3 × 10−72.0 × 10−74.1 × 10−7 | 94970920938 | ✓ | Mo-containing alloys are not susceptible to pitting corrosion in 1 M NaCl | |
Al2CrFeCoCuTiNix | 00.511.52 | ✗ | ✓ | ✗ | ✗ | 0.6 M NaCl 1 M NaOH | −510−430−220−480−500 | 6.8 × 10−53.2 × 10−51.3 × 10−56.4 × 10−56.7 × 10−5 | ✗✗✗✗✗ | Not reported | The general corrosion resistance increases up to x = 1, and then decreases with further addition of Ni | |
FeCoNiCrCux | 00.51 | ✗ | ✓ | ✗ | ✓ | 0.6 M NaCl | −260−290−330 | 3.15 × 10−87.23 × 10−71.32 × 10−6 | 3109080 | ✓ | Preferential dissolution of the Cu-rich FCC phase. FeCoNiCr alloy exhibits better general corrosion resistance than 304 L SS | |
CuCr2Fe2Ni2Mn2 | ✗ | ✓ | ✗ | ✓ | 1 M H2SO4 | −974 | 2.09 × 10−6 | ✗ | ✓ | Higher Cu content and elemental segregation leads to higher corrosion rate | ||
Cu2CrFe2NiMn2 | ✗ | ✓ | ✗ | ✓ | 1 M H2SO4 | −1144 | 4.02 × 10−5 | ✗ | ✓ | |||
Cu0.5CoCrFeNi | ✗ | ✓ | ✗ | ✗ | 0.6 M NaCl | −280 | 2.03 × 10−9 | 70 | ✓ | Lower corrosion resistance than 304 l SS for both the as-cast and aged alloys | ||
Al0.5CoCrCuFeNiBx | 00.20.61 | ✗ | ✓ | ✓ | ✗ | 1 N H2SO4 | −359−365−392−403 | 7.87 × 10−41.03 × 10−32.63 × 10−32.85 × 10−3 | ✗✗✗✗ | ✓ | Superior general corrosion resistance than 304 SS | |
FeCrNiCoBx | ✗ | ✓ | ✗ | ✗ | 0.6 M NaCl | ✗ | ✗ | ✗ | Not reported | Better general corrosion resistance than 304 l SS | ||
FeCoNiCuSnx | 00.020.030.040.050.070.09 | ✗ | ✓ | ✗ | ✓ | 0.6 M NaCl, 5% NaOH | −1030−1089−1097−966−1095−1103−1173 | 9.49 × 10−52.13 × 10−63.23 × 10−69.69 × 10−51.35 × 10−61.86 × 10−62.03 × 10−6 | −490−397−393−421−425−414−433 | Not reported | Better corrosion resistance than 304 SS in NaCl solution. Poorer corrosion resistance than 304 SS in NaOH solution | |
AlxCrFe1.5MnNi0.5 | ✗ | ✓ | ✓ | ✗ | 15% H2SO4 1 M HCl | ✗ | ✗ | ✗ | ✓ | Anodisation in 15 % H2SO4 significantly enhances the corrosion resistance | ||
Al0.5CoCrFeNi | ✗ | ✓ | ✗ | ✗ | 0.6 M NaCl | −570 | 1.7 × 10−7 | 130 | ✓ | Cl− ions preferentially attack the Al–Ni-rich phase | ||
AlCrFeNiCoCu | ✗ | ✓ | ✗ | ✗ | 1 M NaCl | −12 | 3.23 × 10−9 | ✗ | Not reported | Better general corrosion resistance than 304 SS | ||
CoCrCuFeNiNb | ✗ | ✓ | ✓ | ✗ | 1 M/6 M HCl | −397 | 8.93 × 10−5 | ✗ | Not reported | Better general corrosion resistance than 304 SS in HCl | ||
