Abstract
Two austenitic stainless steel grades, 316L and 904L, and
three duplex stainless steel grades, LDX 2101, 2205, and
2507, were erosion-corrosion tested as impeller blade
materials for hydrometallurgical applications. Samples
were attached to the pressure and suction sides of an
impeller and were tested in 50 g/l H2SO4 and 0.5 g/l
Fe2(SO4)3 for 72 h at 80°C and 95 °C in a small-scale
reactor using quartz sand slurry. The results showed that
under lower erosion intensity the ranking of the grades
was similar to that in pure erosion. Under higher erosion
intensity the ranking of the grades changed completely:
lean alloys LDX 2101 and 316L suffered from the highest
mass losses followed by 2205, 2507, and 904L. To clarify
this behavior, the ability of the grades to repassivate
was investigated with scratch tests. It was found that
the ranking could be explained by the repassivation
rates. The only exception was that 2507 showed a similar
repassivation rate to 904L but its erosion-corrosion mass
loss under higher erosion intensity was larger. One
contributing factor to this was found to be the selective
dissolution of the austenite phase of all the tested
duplex grades. The prerequisites for the galvanic
coupling between the phases that was responsible for the
selective dissolution are discussed.
Original language | English |
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Pages (from-to) | 10-21 |
Journal | Wear |
Volume | 364-365 |
DOIs | |
Publication status | Published - 2016 |
MoE publication type | A1 Journal article-refereed |
Keywords
- erosion-corrosion
- slurry
- stainless steels
- sulfuric acid
- wear