Abstract
The corrosion resistance of the steel grades 1.4509 and 1.4301 against sodium and calcium chloride, at 650 and 750 °C is investigated by means of cyclic exposure tests (CETs) in dry air. The formation of chromates as well as volatile metal chlorides and oxychlorides leads to non-protective oxide scales on both steel grades. At 650 and 750 °C and in presence of a salt layer the alloy 1.4301 shows a higher corrosion resistance than the material 1.4509. At 750 °C and in presence of salt, the surface of the steel grade 1.4301 is transformed from a face centered cubic (fcc) to a body centered cubic (bcc) lattice, due to corrosion induced de-alloying. The surfaces of both tested materials deplete in chromium, especially at 750 °C. Consequently, the corrosion resistance of the materials exposed to CET decreases sharply in aqueous corrodants.
| Original language | English |
|---|---|
| Pages (from-to) | 1071-1086 |
| Number of pages | 16 |
| Journal | Materials and Corrosion |
| Volume | 70 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Jun 2019 |
Keywords
- aqueous corrosion
- automotive exhaust systems
- calcium chloride
- high temperature corrosion
- sodium chloride
ASJC Scopus subject areas
- Environmental Chemistry
- Mechanics of Materials
- Mechanical Engineering
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry