TITLE:
Study of Electroslag Remelted and Nitrogen Containing High Speed Tool Steel M41
AUTHORS:
S. A. El Badry, Hossam Halfa, A. Ahmed, A. G. Moustafa
KEYWORDS:
High speed tool steel; Nitrogen; ESR; Mossbauer
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.9 No.1,
January
20,
2010
ABSTRACT: Mossbauer Effect (ME) spectra, microstructure and hardness of some alloyed and conventional
AISI M41 high speed tool steel samples produced by induction furnace as well as after doing
electro-slag refining (ESR) process under different slag compositions have been investigated.
The obtained ME spectra for all samples could be analyzed to a singlet and three sextets. The
appeared singlet in the conventional steel and that alloyed with nitrogen as well as two refined
samples using electro-slag remelting 1 and 2 (ESR1, M41N and ESR2, M41N) can be attributed
to γ–austenite phase, while the singlet that appeared in the refined sample 3 (ESR3, M41N) can
be attributed to some iron nitride of the form ( ε-Fe2N). In the refined sample, which does not contain nitrogen, γ–austenite phase cannot be found and some α-Fe2O3 was detected. The observed three sextets were attributed to three different magnetic martensite phases. It appeared also that some transformations in between the three martensite phases and between martensite and austenite take place, and all these changes were thoroughly discussed. It is interesting to state that the obtained ME results are in agreement with those obtained from optical microscopy and micro-hardness measurements.