The internal-nitriding behavior of 310 stainless steel with and without Al and Ti additions

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Oxidation of Metals; (USA)

DOI:https://doi.org/10.1007/BF00664427· OSTI ID:6016749

Chen, I C; Douglass, D L ^[1]

---

1. Univ. of California, Los Angeles (USA)

The internal-nitriding behavior in ammonia-hydrogen atmospheres of type-310 stainless steel and 310 to which either 2 wt.% Ti or 3 wt.% Al were added was studied over the range of 550-950C. An Fe-24Cr binary alloy was included to assess the role of a BCC crystal structure vs the FCC crystal structure of 310 stainless steel. The BCC alloy exhibited the most rapid kinetics as expected. X-ray diffraction showed only the presence of CrN in all the alloys up to 735C. At 850C and above, both CrN and Cr{sub 2}N were detected. The nonformation of TiN and AlN at lower temperatures is attributed to nucleation problems. Precipitates were extremely fine (unresolvable even at 20,000{times}) at 563C and became much coarser with increasing temperature. The precipitate density, size, and shape varied across the internal-nitriding zone at the higher temperatures. External scaling was noted at 850C and above, however, it was not a continuous film. The activation energy of internal nitriding from 563-735C ranged from 3.8 kcal/mol for 310+3Al; from 850-950C, the activation energy ranged from 44 (310+2Ti) to 56.6 kcal/mol (310+3Al).

• OSTI ID: 6016749
• Journal Information: Oxidation of Metals; (USA), Journal Name: Oxidation of Metals; (USA) Vol. 34:5-6; ISSN 0030-770X; ISSN OXMEA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ACTIVATION ENERGY
ALLOYS
AUSTENITIC STEELS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
COHERENT SCATTERING
CORROSION RESISTANT ALLOYS
DATA
DIFFRACTION
ENERGY
EXPERIMENTAL DATA
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
HIGH TEMPERATURE
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
LATTICE PARAMETERS
MATERIALS
MEASURING METHODS
NICKEL ALLOYS
NITRIDATION
NUMERICAL DATA
SCALING
SCATTERING
STAINLESS STEEL-310
STAINLESS STEELS
STEEL-CR25NI20
STEELS
X-RAY DIFFRACTION