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Laser‐beam surface transformation hardening of hypoeutectoid Ck‐60 steel
Author(s) -
Katsamas Anthony I.,
Zervaki Anna D.,
Haidemenopoulos Gregory N.
Publication year - 1997
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.199700551
Subject(s) - martensite , materials science , microstructure , power density , ferrite (magnet) , hardening (computing) , laser , hardness , metallurgy , case hardening , beam (structure) , composite material , diffusionless transformation , optics , power (physics) , thermodynamics , physics , layer (electronics)
A carbon dioxide laser with a power of 1.5 KW was employed for surface hardening of a hypoeutectoid Ck‐60 steel. The microstructures and hardness profiles were determined as a function of power density and laser beam travel speed. The microstructure in the laser‐beam hardened zone depended on power density and consisted of plate martensite (for high power density) or autotempered martensite (for low power density). In the transition zone of the laser‐beam treated specimens, martensite and ferrite were observed. Case depth and maximum hardness were found to depend on power density and travel speed. A simple one‐dimensional heat flow model has been used for the selection of process parameters and for the prediction of case depth. Calculated and experimentally determined case depths are in good agreement for medium values of power density.