The resistance of 20Cr/25Ni steels to carbon deposition. Pt. 3
Creators
- 1. Central Electricity Generating Board, Berkeley (UK). Berkeley Nuclear Labs.
Description
Specimens of annealed 20Cr/25Ni/Nb, selectively pre-oxidised 20Cr/25Ni/Nb, cold worked 20Cr/25Ni/Nb and TiN-strengthened 20Cr-25Ni steels have been exposed to a 75% CO/CO2 gas atmosphere for periods up to 2000 hrs at 923 K (6500C). Whereas the cold-worked and TiN-strengthened steels show high resistance to this environment, the annealed Nb-stabilized alloy exhibited large amounts of carbon deposition. Associated with these were extensive regions of oxide pitting and gross carburisation of the substrate. By contrast, the selectively preoxidised specimens suffered much less deposition and no evidence for carburisation was found. It was also shown that small quantities of defects in the original preoxidised layer increased the propensity for deposition but did not result in local carburisation. (orig.)
Abstract (German)
Proben aus angelassenem Stahl 20Cr/25Ni/Nb, selektiv voroxidiertem Stahl dieses Typs sowie kaltverformtem 20Cr/25NiNb-Stahl und TiN-verfestigtem 20Cr/25Ni-Stahl wurden bis 2000 h lang in 75% CO/CO2 bei 923 K exponiert. Waehrend die kaltverformten TiN-versteiften Staehle unter diesen Bedingungen sehr verfestigt sind wird auf den angelassenen Nb-stabilisierten Stahl Kohle in betraechtlichen Mengen abgeschieden. In Verbindung damit kommt es zu Oxid-Lochkorrosion auf groesseren Teilen der Oberflaeche und zu einer Aufkohlung des Substrats. Im Gegensatz dazu sind die selektiv voroxidierten Proben weit weniger anfaellig fuer Kohleablagerung und Aufkohlung. Geringe Mengen von Fehlstellen in der voroxidierten Schicht steigern zwar die Anfaelligkeit fuer Kohleablagerung, fuehren jedoch nicht zu oertlicher Aufkohlung. (orig.)Additional details
Additional titles
- Subtitle (English)
- Cold work and selective pre-oxidation
Publishing Information
- Journal Title
- Werkst. Korros.
- Journal Volume
- 38
- Journal Issue
- 5
- Series
- Werkst. Korros.
- Journal Page Range
- 219-224
- ISSN
- 0043-2822
- CODEN
- WSKRA
INIS
- Country of Publication
- Germany
- Country of Input or Organization
- Germany
- INIS RN
- 19016978
- Subject category
- S36: MATERIALS SCIENCE;
- Descriptors DEI
- BINARY MIXTURES; CARBON; CARBON DIOXIDE; CARBON MONOXIDE; CARBURIZATION; COLD WORKING; DEPOSITION; HIGH TEMPERATURE; NIOBIUM ADDITIONS; OXIDATION; PERFORMANCE TESTING; PITTING CORROSION; STEEL-NI25CR20; TITANIUM NITRIDES
- Descriptors DEC
- ALLOYS; AUSTENITIC STEELS; CARBON ADDITIONS; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; CHEMICAL REACTIONS; CHROMIUM ALLOYS; CHROMIUM-NICKEL STEELS; CORROSION; CORROSION RESISTANT ALLOYS; DISPERSIONS; ELEMENTS; FABRICATION; HARDENING; HEAT RESISTING ALLOYS; HIGH ALLOY STEELS; IRON ALLOYS; IRON BASE ALLOYS; MATERIALS WORKING; MIXTURES; NICKEL ALLOYS; NITRIDES; NITROGEN COMPOUNDS; NONMETALS; OXIDES; OXYGEN COMPOUNDS; STAINLESS STEELS; STEELS; SURFACE HARDENING; SURFACE TREATMENTS; TESTING; TITANIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS