Effects of simultaneous boron and nitrogen implantation on microhardness and fatigue properties of Fe-13Cr-15Ni alloys

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02646687· OSTI ID:5262650

Rao, G R; Lee, E H; Mansur, L K ^[1]; Chin, B A ^[2]

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1. Oak Ridge National Lab., TN (United States)
2. Auburn Univ., AL (United States). Materials Engineering Dept.

Eight complex austenitic stainless steel alloys based on the composition Fe-13Cr-15Ni-2Mo-2Mn-0.2Ti-0.8Si-0.06C were implanted simultaneously with 400-keV B[sup +] and 550-keV N[sup +] ions and were investigated for changes in fatigue properties and surface microhardness. The near-surface hardness of all eight alloys improved, but the fatigue life of each decreased. These findings were contrary to those obtained in an earlier study using four simple Fe-13Cr-15Ni alloys, where the dual implantation improved fatigue life by up to 250 pct. While unimplanted specimens failed by slip-band crack initiation, it was hypothesized that the dual implantation suppressed slip to the extent that fewer slip-band cracks were initiated and these were subjected to accelerated crack propagation. In addition, grain-boundary cracking was promoted, yielding a lower fatigue life. Support for this hypothesis was obtained by a study of single crystals of Fe-15Cr-15Ni, which were also implanted with B[sup +] and N[sup +]. The dual implantation caused a lower fatigue life due to concentration of slip along a few slip bands to relieve applied stress. Evidence of grain-boundary cracking was obtained using the four simple alloys, which were subjected to triple ion implantation with B[sup +], N[sup +], and C[sup +].

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5262650
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 25:1; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360106* -- Metals & Alloys-- Radiation Effects
ALLOYS
AUSTENITIC STEELS
BORON IONS
CHARGED PARTICLES
CHROMIUM ALLOYS
DATA
EXPERIMENTAL DATA
INFORMATION
ION IMPLANTATION
IONS
IRON ALLOYS
IRON BASE ALLOYS
MECHANICAL PROPERTIES
NICKEL ALLOYS
NICKEL STEELS
NICKEL-CHROMIUM STEELS
NITROGEN IONS
NUMERICAL DATA
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
STEELS